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Modulating the Experience of Agency: A Positron Emission Tomography Study
Abstract
This study investigated agency, the feeling of being causally involved in an action. This is the feeling that leads us to attribute an action to ourselves rather than to another person. We were interested in the effects of experimentally modulating this experience on brain areas known to be involved in action recognition and self-recognition. We used a device that allowed us to modify the subject's degree of control of the movements of a virtual hand presented on a screen. Four main conditions were used: (1) a condition where the subject had a full control of the movements of the virtual hand, (2) a condition where the movements of the virtual hand appeared rotated by 25 degrees with respect to the movements made by the subject, (3) a condition where the movements of the virtual hand appeared rotated by 50 degrees, and (4) a condition where the movements of the virtual hand were produced by another person and did not correspond to the subject's movements. The activity of two main brain areas appeared to be modulated by the degree of discrepancy between the movement executed and the movement seen on the screen. In the inferior part of the parietal lobe, specifically on the right side, the less the subject felt in control of the movements of the virtual hand, the higher the level of activation. A reverse covariation was observed in the insula. These results demonstrate that the level of activity of specific brain areas maps onto the experience of causing or controlling an action. The implication of these results for understanding pathological conditions is discussed.
... By introducing angular biases in visual feedback such studies have outlined how accurately participants can monitor their movements, in other words, their Motor Awareness. These studies have reliably reported that MA is limited so that movements with angular deviations of 6.5°-15° or judged to be un-deviated, even if participants perform automatic motor corrections [20], [23], [27], [28]. Similarly, studies that provided temporally manipulated visual feedback (hand movements) showed that participants MA is limited to approximately 150-200ms [20], [23], [25]. ...
... These studies have reliably reported that MA is limited so that movements with angular deviations of 6.5°-15° or judged to be un-deviated, even if participants perform automatic motor corrections [20], [23], [27], [28]. Similarly, studies that provided temporally manipulated visual feedback (hand movements) showed that participants MA is limited to approximately 150-200ms [20], [23], [25]. Similar research has also included mediated action outcomes such as the occurrence of a tone after a button-press [29]- [32], an approach further applied to investigate voluntary action and intention [33]- [35]. ...
... Although participants were instructed to base their responses on the remapped tactile sensations on their back, their actual foot-strike may have still interfered with the present MA judgments. In terms of the central monitoring framework [23], which has been argued to depend on a comparison of internal representations and predictions about our movements with the actual reafferent sensory information (but also with our intended or desired state; see [19]), this corresponds to a strong conflict in the feedback source. Such uncertainty may additionally contribute to the higher temporal thresholds observed here along with potentially differing relative weighting of feedback cues [70]. ...
p>We developed an untethered robotic system that provides walking-related sensory feedback remapped non-invasively to the wearer’s back. Using the so-called FeetBack system, we investigated how accurately healthy individuals can monitor remapped, tactile locomotor feedback (motor awareness) and how this affects their walking characteristics (adaptation).</p
... By introducing angular biases in visual feedback such studies have outlined how accurately participants can monitor their movements, in other words, their Motor Awareness. These studies have reliably reported that MA is limited so that movements with angular deviations of 6.5°-15° or judged to be un-deviated, even if participants perform automatic motor corrections [20], [23], [27], [28]. Similarly, studies that provided temporally manipulated visual feedback (hand movements) showed that participants MA is limited to approximately 150-200ms [20], [23], [25]. ...
... These studies have reliably reported that MA is limited so that movements with angular deviations of 6.5°-15° or judged to be un-deviated, even if participants perform automatic motor corrections [20], [23], [27], [28]. Similarly, studies that provided temporally manipulated visual feedback (hand movements) showed that participants MA is limited to approximately 150-200ms [20], [23], [25]. Similar research has also included mediated action outcomes such as the occurrence of a tone after a button-press [29]- [32], an approach further applied to investigate voluntary action and intention [33]- [35]. ...
... Although participants were instructed to base their responses on the remapped tactile sensations on their back, their actual foot-strike may have still interfered with the present MA judgments. In terms of the central monitoring framework [23], which has been argued to depend on a comparison of internal representations and predictions about our movements with the actual reafferent sensory information (but also with our intended or desired state; see [19]), this corresponds to a strong conflict in the feedback source. Such uncertainty may additionally contribute to the higher temporal thresholds observed here along with potentially differing relative weighting of feedback cues [70]. ...
p>We developed an untethered robotic system that provides walking-related sensory feedback remapped non-invasively to the wearer’s back. Using the so-called FeetBack system, we investigated how accurately healthy individuals can monitor remapped, tactile locomotor feedback (motor awareness) and how this affects their walking characteristics (adaptation).</p
... However, Farrer and collaborators investigated the neural signatures of the sense of agency, using similar methods, such as the systematic manipulation of visual feedback to alter the experience of one's body in action. They demonstrated that activity in the right PIC was correlated with the degree of matching between the performed and the viewed movement, and thus with selfattribution [151]. Beyond its involvement in the most primitive aspects of the SSS, the right insula seems to be implicated in more highly elaborated levels of awareness, such as visual self-recognition in comparison with the processing of another, highly familiar person's face [152,153]. ...
... Our review found results supporting Craig's hypothesis of a posterior-to-anterior insular axis of complexity [40]. Indeed, some studies support the notion that elementary aspects of the SSS, as assessed by interoception, body ownership or sense of agency, are sustained by the PIC [148][149][150][151]167], while more highly elaborated levels of the SSS, such as metacognitive abilities and emotional awareness, are sustained by the AIC [154,155,176]. Furthermore, as proposed by Craig's work and pioneering experiments, the SSS seems to be specifically sustained by the right insula, thus suggesting that some aspects of the self could be lateralized [6,32,35,46,[150][151][152][153]167,175]. ...
... Indeed, some studies support the notion that elementary aspects of the SSS, as assessed by interoception, body ownership or sense of agency, are sustained by the PIC [148][149][150][151]167], while more highly elaborated levels of the SSS, such as metacognitive abilities and emotional awareness, are sustained by the AIC [154,155,176]. Furthermore, as proposed by Craig's work and pioneering experiments, the SSS seems to be specifically sustained by the right insula, thus suggesting that some aspects of the self could be lateralized [6,32,35,46,[150][151][152][153]167,175]. Conversely, the involvement of the left insula is often reported in the literature when subjects are thinking of personal information about themselves [111,153,183], whereas the specific roles of the AIC and the PIC in the SC remain unclear. ...
The insula is a multiconnected brain region that centralizes a wide range of information, from the most internal bodily states, such as interoception, to high-order processes, such as knowledge about oneself. Therefore, the insula would be a core region involved in the self networks. Over the past decades, the question of the self has been extensively explored, highlighting differences in the descriptions of the various components but also similarities in the global structure of the self. Indeed, most of the researchers consider that the self comprises a phenomenological part and a conceptual part, in the present moment or extending over time. However, the anatomical substrates of the self, and more specifically the link between the insula and the self, remain unclear. We conducted a narrative review to better understand the relationship between the insula and the self and how anatomical and functional damages to the insular cortex can impact the self in various conditions. Our work revealed that the insula is involved in the most primitive levels of the present self and could consequently impact the self extended in time, namely autobiographical memory. Across different pathologies, we propose that insular damage could engender a global collapse of the self.
... The role of predictions and prediction errors in modulating SoA was confirmed by a considerable amount of studies. Indeed, SoA is impaired when movement trajectory is different from what is expected (Daprati et al., 1997;David et al., 2016;Farrer, Bouchereau et al., 2008;Farrer, Franck, Georgieff et al., 2003;Farrer, Franck, Paillard et al., 2003;van den Bos and Jeannerod, 2002;Villa et al., 2018); when movements and action outcomes are delayed (Farrer et al., 2013;Sato and Yasuda, 2005;Shanks et al., 1989;Villa et al., 2021;Wen et al., 2015a. For a review, see Wen, 2019); and when the physical properties of the generated external outcome (e.g., pitch of a tone; color change of a visual stimulus on screen) do not coincide with predictions (Barlas and Kopp, 2018;Kühn et al., 2011;Sato, 2009;Sato and Yasuda, 2005;Spengler et al., 2009. ...
... • Attribution of the action/outcome to "self" or "other" (David et al., 2007(David et al., , 2016Farrer, Frey et al., 2008) • Evaluation of the correspondence between executed and observed action (Farrer, Franck, Georgieff et al., 2003;Farrer, Franck, Paillard et al., 2003;Franck et al., 2001;van den Bos and Jeannerod, 2002) ...
... In addition, the Extrastriate Body Area (EBA) which is commonly activated by the selective processing of bodily stimuli (Downing et al., 2001;Moreau et al., 2018;Moreau, Parrotta et al., 2020;Urgesi et al., 2004), may play a role in distinguishing between one's own and another person's actions (David et al., 2007(David et al., , 2009). Thus, it seems plausible that TPJ and EBA, as well as the IPL (Farrer, Franck, Georgieff et al., 2003;Farrer, Frey et al., 2008;Farrer and Frith, 2002), may support the "who system". ...
While the Sense of Agency (SoA) – the experience of controlling actions – is linked to motoric processes, the effects of non-motoric cues remain uncertain. We performed a systematic review investigating whether SoA is modulated by social, affective, and non-motoric bodily cues like internal bodily signals (IBSs) and Sense of Ownership (SoO). We searched Scopus and Pubmed and checked additional sources (e.g., citation searching). We identified 160 articles investigating social (67), affective (71) and non-motoric bodily cues (28), and calculated the percentage of studies supporting SoA modulation. SoA is influenced by social cues (92.54%), like the presence of interactive agents, and their status. Concerning affective cues (88.73%), reward-related information and affective states modulate SoA, but the effects of outcome valence are inconsistent. Regarding bodily cues (78.57%), SoO informs SoA, but the impact of IBSs is unclear. Overall, we show that diverse non-motoric cues modulate SoA. We submit that the brain evaluates different non-motoric cues in partially distinct circuits, before comparing them in a fronto-parietal network grounding SoA modulation.
... combines temporally aligned signals from various sensory sources and plays a pivotal role in maintaining agency and embodiment [10][11][12]. Neurophysiological studies in virtual reality revealed a set of brain regions implicated in agency perception during teleoperation. The activation of posterior parietal regions, including the right angular gyrus, augments sensorimotor control over avatars [10], while a network involving the right supramarginal gyrus, the left anterior inferior parietal lobule, the anterior insula, and the right temporoparietal junction detects agency mismatches [11]. ...
... Prefrontal cortex involvement is crucial for conscious agency experiences [11]. Farrer and colleagues observed increased cerebral blood flow in the right inferior parietal lobule during VR-induced loss of agency, as well as reduced activity in the right posterior insula and cerebellum [12]. EEG studies by Bu-Omer and colleagues and Kang and colleagues indicate that increased alpha and beta bands are associated with decreased agency perception, while heightened control correlates with decreased alpha relative power and reduced phase coherence within frontal regions [13,14]. ...
Agency is central to remote actions, and it may enhance skills learning due to a partial overlap between brain structures and networks, the promotion of confidence towards a telemanipulator, and the feeling of congruence of the motor choice to the motor plan. We systematically reviewed studies aiming to verify the role of agency in improving learning. Fifteen studies were selected from MEDLINE and Scopus ®. When a mismatch is introduced between observed and performed actions, the decrease in agency and learning is proportional to the intensity of the mismatch, which is due to greater interference with the motor programming. Thanks to multisensory integration, agency and learning benefit both from sensory and performance feedback and from the timing of feedback based on control at the goal level or the perceptual-motor level. This work constitutes a bedrock for professional teleoperation settings (e.g., robotic surgery), with particular reference to the role of agency in performing complex tasks with remote control.
... Previous neuroimaging studies typically modulate the magnitude of SoA by either manipulating the authorship of the action, e.g. externally moving people's effector to generate passive "actions" (Balslev et al. 2006;Tsakiris et al. 2010;Kühn et al. 2013;Straube et al. 2017;van Kemenade et al. 2017van Kemenade et al. , 2019Uhlmann et al. 2020;Zapparoli et al. 2020), or perturbing the sensory feedback of the movement or its outcome by implementing temporal and spatial discrepancies (Farrer and Frith 2002;Farrer et al. 2003Farrer et al. , 2008Leube et al. 2003aLeube et al. , 2003bMatsuzawa et al. 2005;Balslev et al. 2006;David et al. 2007;Schnell et al. 2007;Spengler et al. subcortical regions such as the cerebellum and striatum (Haggard 2017;Seghezzi et al. 2019;Charalampaki et al. 2022). ...
... This finding supports the reconstructive mechanism of SoA, which emphasizes that the TB is grounded by retrospective causality since the right AG and IPL participate in both SoA and causal processing in general. The right IPL has been one of the most frequently revealed neural correlates of SoA (Farrer et al. 2003(Farrer et al. , 2008Schnell et al. 2007;Nahab et al. 2011;Chambon et al. 2013Chambon et al. , 2015. Even anosognosia patients who often assert that they performed an action with their paralyzed, immobile limb typically have lesions in the right parietal lobule (Fotopoulou et al. 2008). ...
Sense of agency (SoA) is the sensation that self-actions lead to ensuing perceptual consequences. The prospective mechanism emphasizes that SoA arises from motor prediction and its comparison with actual action outcomes, while the reconstructive mechanism stresses that SoA emerges from retrospective causal processing about the action outcomes. Consistent with the prospective mechanism, motor planning regions were identified by neuroimaging studies using the temporal binding (TB) effect, a behavioral measure often linked to implicit SoA. Yet, TB also occurs during passive observation of another’s action, lending support to the reconstructive mechanism, but its neural correlates remain unexplored. Here, we employed virtual reality (VR) to modulate such observation-based SoA and examined it with functional magnetic resonance imaging (fMRI). After manipulating an avatar hand in VR, participants passively observed an avatar’s “action” and showed a significant increase in TB. The binding effect was associated with the right angular gyrus and inferior parietal lobule, which are critical nodes for inferential and agency processing. These results suggest that the experience of controlling an avatar may potentiate inferential processing within the right inferior parietal cortex and give rise to the illusionary SoA without voluntary action.
... Most studies in healthy participants combined functional neuroimaging with experimental manipulations of the bodily self through synchronous, but mismatching, multisensory stimulation, altering specific components of the bodily self (reviewed in Blanke, 2012;Dieguez & Lopez, 2017). Illusory ownership of a fake hand (Botvinick & Cohen, 1998;Ehrsson et al., 2004), self identification with a virtual body and altered self location (Ionta et al., 2011;Lenggenhager et al., 2007;Nakul, Orlando-Dessaints, et al., 2020), altered sense of agency (Farrer et al., 2003), or distortions in the structure and size of the felt body (de Vignemont et al., 2005;Ehrsson, Kito, Sadato, Passingham & Naito, 2005) have been induced using such techniques in healthy participants (see Table 1 for a summary). ...
... Other studies found that the temporo-parietal junction, primary somatosensory cortex, premotor cortex, cingulate cortex, and the posterior superior temporal gyrus are related to illusory changes in the self location Ionta et al., 2011). The sense of agency on the other hand, has been related to the insula and inferior parietal cortex (Chambon et al., 2013;Farrer et al., 2003;Farrer, Frey, et al., 2008, Farrer, Bouchereau, et al., 2008Farrer & Frith, 2002), whereas experimentally-induced changes in the perceptual body image (perceived shape and size or posture of the body) have been related to the postcentral sulcus, intraparietal sulcus, insula, and inferior parietal lobule Kavounoudias et al., 2008;Naito et al., 2017). While the neural networks revealed by these neuroimaging studies are typically based on a correlative approach, a more causal link has been suggested by non-invasive transcranial T A B L E 1 Five core phenomenal experiences underlying the bodily self ...
An increasing amount of recent research has focused on the multisensory and neural bases of the bodily self. This pre-reflective form of self is considered as multifaceted, incorporating phenomenal components, such as self location, body ownership, first-person perspective, agency, and the perceptual body image. Direct electrical brain stimulation (EBS) during presurgical evaluation of epilepsy and brain tumor re-section is a unique method to causally relate specific brain areas to the various phenomenal components of the bodily self. We conducted a systematic review of the literature describing altered phenomenal experience of the bodily self evoked by EBS. We included 42 articles and analyzed self reports from 221 patients. Three-dimensional density maps of EBS revealed that stimulation in the middle cingulum, inferior parietal lobule, supplementary motor area, posterior insula, hippocampal complex/amygdala, and precuneus most consistently altered one or several components of the bodily self. In addition, we found that only EBS in the parietal cortex induced disturbances of all five components of the bodily self considered in this review article. These findings inform current neuroscientific models of the bodily self.
... Also, Ehrsson et al. (2004) compared the functional images obtained after the SoO's development with those collected before the illusion occurs, showing enhanced activation of the left precentral sulcus and the right cerebellum. The areas supporting the SoA are instead the prefrontal and parietal cortex (Farrer et al., 2003;Farrer & Frith, 2002;Fink et al., 1999), the dorsolateral prefrontal cortex (Fink et al., 1999), the insula (Brass & Haggard, 2007;Farrer et al., 2003;Karnath et al., 2005;Klein et al., 2007), and the cerebellum (Fink et al., 1999). ...
... Also, Ehrsson et al. (2004) compared the functional images obtained after the SoO's development with those collected before the illusion occurs, showing enhanced activation of the left precentral sulcus and the right cerebellum. The areas supporting the SoA are instead the prefrontal and parietal cortex (Farrer et al., 2003;Farrer & Frith, 2002;Fink et al., 1999), the dorsolateral prefrontal cortex (Fink et al., 1999), the insula (Brass & Haggard, 2007;Farrer et al., 2003;Karnath et al., 2005;Klein et al., 2007), and the cerebellum (Fink et al., 1999). ...
The Sense of Ownership (SoO) and the Sense of Agency (SoA) are two key components of bodily self-consciousness. In this experiment, we investigated how they are affected by variations in the ecological validity of the moving Rubber Hand Illusion (mRHI) paradigm, which typically include three movement conditions: active congruent, passive congruent, and active incongruent. These conditions were either in a session in which no auditory feedback associated with finger-tapping was eliminated, or in a session in which such a feedback occurred. Since the presence of the auditory feedback more closely corresponds to what individuals experience in daily life when they tap their finger on a surface, sessions with feedback are more ecologically valid, and should thus result in a more marked SoO. Results indicated that in the active movement condition in which the illusion is typically found (congruent), the effect was enhanced when the feedback was present. This advantage emerged on both on objective and subjective measures of SoO. The SoA, on the other hand, is not affected by the auditory feedback.
... In an anatomical study, Karnath et al. [127] found that the posterior insula was most frequently damaged in RBD patients with anosognosia. Based on a PET study showing that the mismatch between an action and its corresponding visual feedback de-activates the right posterior insula (while activating the right TPJ [128]), Karnath and co-workers interpreted anosognosia as deriving from defective motor-visual comparison in this brain region. These authors cautiously noted that the insular lesion involved underlying white matter connections, and that this might have produced a functional impairment of a network of areas including the somatosensory cortex (SI, SII), the superior and inferior parietal lobule, and the premotor cortex. ...
... The above summarised evidence highlights the involvement of the right TPJ in the network of areas that regulate motor awareness. While the contribution of pre-motor areas in the direct comparison between expected and actual motor signals is now well documented [125,126] the right TPJ could be involved in the detection of multimodal mismatches like the one between proprioceptive signals from self-initiated action and corresponding visual feedback [55,128] or the coding and integration in one's beliefs of mismatches between selfestimated motor abilities and self-perceived counterfactual evidence or counterfactual evidence signalled by caregivers. Here we also sketch the possibility that while pre-motor cortex supports on-line awareness of motor mismatches, the TPJ is engaged in cumulating these signals for updating long-term beliefs on one's own body schema and motor abilities. ...
Experimental and theoretical studies have tried to gain insights into the involvement of the Temporal Parietal Junction (TPJ) in a broad range of cognitive functions like memory, attention, language, self-agency and theory of mind. Recent investigations have demonstrated the partition of the TPJ in discrete subsectors. Nonetheless, whether these subsectors play different roles or implement an overarching function remains debated. Here, based on a review of available evidence, we propose that the left TPJ codes both matches and mismatches between expected and actual sensory, motor, or cognitive events while the right TPJ codes mismatches. These operations help keeping track of statistical contingencies in personal, environmental, and conceptual space. We show that this hypothesis can account for the participation of the TPJ in disparate cognitive functions, including “humour”, and explain: a) the higher incidence of spatial neglect in right brain damage; b) the different emotional reactions that follow left and right brain damage; c) the hemispheric lateralisation of optimistic bias mechanisms; d) the lateralisation of mechanisms that regulate routine and novelty behaviours. We propose that match and mismatch operations are aimed at approximating “free energy”, in terms of the free energy principle of decision-making. By approximating “free energy”, the match/mismatch TPJ system supports both information seeking to update one's own beliefs and the pleasure of being right in one's own' current choices. This renewed view of the TPJ has relevant clinical implications because the misfunctioning of TPJ-related “match” and “mismatch” circuits in unilateral brain damage can produce low-dimensional deficits of active-inference and predictive coding that can be associated with different neuropsychological disorders.
... Nevertheless, the MACM results question the conclusion that thalamic involvement as such is the critical distinguishing factor between physically perceived and observed touch. As a third hypothesis, also the insula may play a crucial role in distinguishing observed from experienced touch (Farrer et al., 2003;Karnath, Baier, & Nägele, 2005). Research here seems not conclusive. ...
Studies have consistently demonstrated that the mere observation of touch engages our own somatosensory cortices. However, a systematic evaluation of the involved networks is missing. Here, we present results of a meta-analytic connectivity modelling (MACM) approach based on clusters revealed by activation likelihood estimation (ALE) combined with resting state analysis to detect networks subserving our ability to empathize with tactile experiences of other people. ALE analysis revealed 8 clusters in frontal, temporal, and parietal brain areas, which behavioral domain profiles predominantly refer to cognition and perception. The MACM analysis further identified distinct networks that are subserved by subcortical structures, revealed that all clusters involved in touch observation are connected to dorso-medial frontal and anterior cingulate cortex control regions, and showed that medial temporal lobe memory structures do not inform network activation during touch observation (confirmed by post hoc resting state connectivity analyses). Our data highlight the importance of higher-level control areas and suggest only a minor role for past bodily experiences in the ad hoc perception of other people’s experiences.
... Neuroimaging studies found the role of the right superior marginal gyrus (SMG), as a part of the right temporo-parietal junction (TPJ), in self-other distinction 19,20 . The posterior portion of the right TPJ involves in non-affective self-other distinction 21,22 . The potential rationale behind this function of the rTPJ could be elucidated by considering its fundamental roles, which encompass spatial perception 23 , mental rotation 24 , the representation of distinct self and other aspects 25 , and inhibitory processes that prioritize the consideration of others over the self 26 . ...
Our perception of physical distance to individuals and stimuli is influenced by our mental distance and relatedness. The present study aimed to investigate the role of the dorsolateral prefrontal cortex (dlPFC), ventromedial prefrontal cortex (vmPFC), and right temporoparietal junction (rTPJ) in interpersonal comfortable distance and approach behaviors towards emotional stimuli. Twenty healthy volunteers received brain stimulation in four separate sessions with a one-week interval, including anodal left dlPFC, anodal right vmPFC, anodal rTPJ, and sham condition, with an extracranial return electrode. Our results revealed an increase in interpersonal distance during anodal rTPJ stimulation and a decrease in distance to positive pictures during anodal vmPFC stimulation. These findings suggest that the rTPJ plays a role in the perceptual component of self-other distancing, while the vmPFC is involved in approaching positive emotions.
... "A brain in a vat" (BIV), without any bodily input, as the homonymous thought experiment postulates it to be (Block, 2005), would not have any visual experience due to the fact that it would not be able to interact with the environment. Sensory processing and the ability to control one's bodily movements, the so-called "sensorimotor coupling with the environment, " are thus mandatory for visual conscious experience (Farrer and Frith, 2002;Farrer et al., 2003;Haggard, 2005;Tsakiris et al., 2007). Moreover, that perfectly fits the neuroscientists' demonstration that consciousness and action seem to sometimes recruit the same neural networks used in the interaction with the environment (Frith et al., 2000;Leube et al., 2003). ...
The new approach in cognitive science largely known as “4E cognition” (embodied/embedded/enactive/extended cognition), which sheds new light on the complex dynamics of human consciousness, seems to revive some of Aristotle's views. For instance, the concept of “nature” ( phusis ) and the discussion on “active intellect” ( nous poiêtikos ) may be particularly relevant in this respect. Out of the various definitions of “nature” in Aristotle's Physics, On the Parts of Animals and Second Analytics , I will concentrate on nature defined as an inner impulse to movement, neither entirely “corporeal,” nor entirely “incorporeal,” and neither entirely “substantial,” nor entirely “accidental.” Related to that, I will consider the distinction in On the Soul between the “active” and the “passive” intellect, which Aristotle asserted as generally present in “nature” itself. By offering a conceptual and historical analysis of these views, I intend to show how the mind–body problem, which is essential for the explanation of consciousness, could be somewhat either eluded or transcended by both ancients and contemporaries on the basis of a subtle account of causation. While not attempting to diminish the impact of the Cartesian paradigm, which led to the so-called “hard problem of consciousness,” I suggest that the most recent neuroscience discoveries on the neurophysiological phenomena related to human consciousness could be better explained and understood if interpreted within a 4E cognition paradigm, inspired by some Aristotelian views.
... The brain performs this computation by comparing the motor command with the feed-forward signal issued together with it and the feedback signal detected by the sensory system. To investigate the neural substrate that allows the sense of agency, Farrer et al. [35] used a joystick device and modulated the feedback by showing on a computer screen the movement of a virtual hand that was either compatible or had different degrees of discrepancy between what was executed, and the movement seen on the screen. The main findings relying upon blood flow positron emission tomography (PET) were that the less subjects felt in control of the movements of the virtual hand, the higher the level of activation in the inferior part of the right temporal parietal junction (TPJ), while a reverse covariation was observed in the right posterior insula. ...
Debates about the concept of Free Will date back to ancient times. About 40 years ago, Benjamin Libet designed an experiment showing that the conscious intention to move is preceded by a specific pattern of brain activation. His finding suggested that unconscious processes determine our decisions. Libet-style experiments have continued to dominate the debate about Free Will, pushing some authors to argue that the existence of Free Will is a mere illusion. We believe that this dispute is because we often measure Free Will using arbitrary human decisions rather than deliberate actions. After reviewing the definition of Free Will and the related literature, we conclude that the scientific evidence does not disprove the existence of Free Will. However, our will encounters several constraints and limitations that should be considered when evaluating our deeds’ personal responsibility.
... behavioral [Sato & Yasuda, 2005;Tsakiris et al., 2006, see David et al. (2008 for a review] and neuroimaging (David et al., 2007;Farrer et al., 2003;Farrer & Frith, 2002, for a recent meta-analysis see Zito et al., 2020) studies have addressed the cognitive architecture and neural basis for the SoA, highlighting the influence of prediction-outcome consistency on the SoA attribution (Frith et al., 2000;Miall & Wolpert, 1996;Synofzik et al., 2008). Importantly, the ability to distinguish self versus externally generated actions lies at the heart of the concept of agency and individual responsibility in our society, concerning important issues such as moral and legal status of actions (Haggard & Tsakiris, 2009). ...
Being able to distinguish between self and externally generated actions is a key factor influencing learning and adaptive behavior. Previous literature has highlighted that whenever a person makes or perceives an error, a series of error-related potentials (ErrPs) can be detected in the electroencephalographic (EEG) signal, such as the error-related negativity (ERN) component. Recently, ErrPs have gained a lot of interest for the use in brain-computer interface (BCI) applications, which give the user the ability to communicate by means of decoding his/her brain activity. Here, we explored the feasibility of employing a support vector machine classifier to accurately disentangle self-agency errors from other-agency errors from the EEG signal at a single-trial level in a sample of 23 participants. Our results confirmed the viability of correctly disentangling self/internal versus other/external agency-error attributions at different stages of brain processing based on the latency and the spatial topographical distribution of key ErrP features, namely, the ERN and P600 components, respectively. These results offer a new perspective on how to distinguish self versus externally generated errors providing new potential implementations on BCI systems.
... Apart from the above mentioned key role in the motor system evidence suggests the pre-SMA/SMA to be highly relevant for cognitive functions such as attention, temporal processing 61-64 , problem solving and working memory capabilities in schizophrenia 65,66 , as well as in early psychosis 67,68 . Finally SMA dysfunction has been associated with altered sense of agency 52,[69][70][71] . ...
Negative symptoms (NS) are a core component of schizophrenia affecting community functioning and quality of life. We tested neural correlates of NS considering NS factors and consensus subdomains. We assessed NS using the Clinical Assessment Interview for Negative Symptoms and the Scale for Assessment of Negative Symptoms. Arterial spin labeling was applied to measure resting-state cerebral blood flow (rCBF) in 47 schizophrenia patients and 44 healthy controls. Multiple regression analyses calculated the relationship between rCBF and NS severity. We found an association between diminished expression (DE) and brain perfusion within the cerebellar anterior lobe and vermis, and the pre-, and supplementary motor area. Blunted affect was linked to fusiform gyrus and alogia to fronto-striatal rCBF. In contrast, motivation and pleasure was not associated with rCBF. These results highlight the key role of motor areas for DE. Considering NS factors and consensus subdomains may help identifying specific pathophysiological pathways of NS.
... At the neural level, several cortical areas have been described as the neural structures of self-other discrimination. Neuroimaging studies found the role of the right superior marginal gyrus (SMG), as a part of the right temporo-parietal junction (TPJ), in self-other distinction ( The posterior portion of the right TPJ involves in non-affective self-other distinction (Blanke et al., 2005;Farrer et al., 2003). Furthermore, the ventromedial prefrontal cortex (vmPFC) is involved in both self and other perception (Heatherton, 2011). ...
Our perception of physical distance to individuals and stimuli is influenced by our mental distance and relatedness. The present study aimed to investigate the role of the dorsolateral prefrontal cortex (dlPFC), ventromedial prefrontal cortex (vmPFC), and right temporoparietal junction (rTPJ) in interpersonal comfortable distance and approach behaviors towards emotional stimuli. Twenty healthy volunteers received brain stimulation in four separate sessions with a one-week interval, including anodal left dlPFC, anodal right vmPFC, anodal rTPJ, and sham condition, with an extracranial return electrode. Our results revealed an increase in interpersonal distance during anodal rTPJ stimulation and a decrease in distance to positive pictures during anodal vmPFC stimulation. These findings suggest that the rTPJ plays a role in the perceptual component of self-other distancing, while the vmPFC is involved in approaching positive emotions.
... 16,17 Within the so-called "agency network," the temporoparietal junction is an important hub for aligning feedforward and feedback information, with abnormal activation during action authorship perception being documented in patients with FMD. 16,18 Taking a conceptual view on these findings, a predictive coding framework proposed that in patients with FMD 19 there is a down-weighting of "bottom-up" sensory information in favor of "top-down" predictions (prior beliefs, feedforward information), reducing the quality and relevance of sensory information (feedback information) available to the individual. 6 This was also shown in a study investigating patients with FMD in a visual probabilistic reasoning task. ...
Background:
Although functional neurological movement disorders (FMD) are characterized by motor symptoms, sensory processing has also been shown to be disturbed. However, how the integration of perception and motor processes, essential for the control of goal-directed behavior, is altered in patients with FMD is less clear. A detailed investigation of these processes is crucial to foster a better understanding of the pathophysiology of FMD and can systematically be achieved in the framework of the theory of event coding (TEC).
Objective:
The aim was to investigate perception-action integration processes on a behavioral and neurophysiological level in patients with FMD.
Methods:
A total of 21 patients and 21 controls were investigated with a TEC-related task, including concomitant electroencephalogram (EEG) recording. We focused on EEG correlates established to reflect perception-action integration processes. Temporal decomposition allowed to distinguish between EEG codes reflecting sensory (S-cluster), motor (R-cluster), and integrated sensory-motor processing (C-cluster). We also applied source localization analyses.
Results:
Behaviorally, patients revealed stronger binding between perception and action, as evidenced by difficulties in reconfiguring previously established stimulus-response associations. Such hyperbinding was paralleled by a modulation of neuronal activity clusters, including reduced C-cluster modulations of the inferior parietal cortex and altered R-cluster modulations in the inferior frontal gyrus. Correlations of these modulations with symptom severity were also evident.
Conclusions:
Our study shows that FMD is characterized by altered integration of sensory information with motor processes. Relations between clinical severity and both behavioral performance and neurophysiological abnormalities indicate that perception-action integration processes are central and a promising concept for the understanding of FMD. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
... In other work, anomalous activity Review of the temporoparietal junction in individuals with schizophrenia has been shown to lead to a misattribution of their own actions to originate from others. 79 Further neuroimaging and sensorimotor experimental data support the view that impaired multisensory integration might lead to weakened bodily selfprocessing. Lesion mapping of patients experiencing felt presence identified common cortical hubs (ie, frontoparietal, insular, and temporoparietal cortices) that were associated with reports of more frequent felt-presence experiences than in controls. ...
The felt presence experience is the basic feeling that someone else is present in the immediate environment, without clear sensory evidence. Ranging from benevolent to distressing, personified to ambiguous, felt presence has been observed in neurological case studies and within psychosis and paranoia, associated with sleep paralysis and anxiety, and recorded within endurance sports and spiritualist communities. In this Review, we summarise the philosophical, phenomenological, clinical, and non-clinical correlates of felt presence, as well as current approaches that use psychometric, cognitive, and neurophysiological methods. We present current mechanistic explanations for felt presence, suggest a unifying cognitive framework for the phenomenon, and discuss outstanding questions for the field. Felt presence offers a sublime opportunity to understand the cognitive neuroscience of own-body awareness and social agency detection, as an intuitive, but poorly understood, experience in health and disorder.
... Functionally, there have been recurrent reports about the reduced activation of SMA during motor and mental tasks (Crespo-Facorro et al., 1999;Guenther et al., 1994;Ortuno et al., 2005;Rogowska et al., 2004;Schröder et al., 1995) and a wide range of neurocognitive tasks in SZ (Pic o-Pérez et al., 2022) and in early psychosis patients (Horne et al., 2022;Vanes et al., 2019). SMA dysfunction has also been associated with temporal processing deficit in SZ (as a measure of cognitive malfunction) (Alústiza et al., 2017;Davalos et al., 2011;Ortuño et al., 2011) and with reduced sense of agency (a common positive symptom of psychosis) (Farrer et al., 2003;Nachev et al., 2008;Wolpe et al., 2020;Yomogida et al., 2010). Our CCA analysis revealed that the selfinhibition of SMA at resting state is significantly correlated with the cognitive performance of SZ patients, above and beyond the other effective connections. ...
Schizophrenia (SZ) is a severe mental disorder characterized by failure of functional integration (aka dysconnection) across the brain. Recent functional connectivity (FC) studies have adopted functional parcellations to define subnetworks of large-scale networks, and to characterize the (dys)connection between them, in normal and clinical populations. While FC examines statistical dependencies between observations, model-based effective connectivity (EC) can disclose the causal influences that underwrite the observed dependencies. In this study, we investigated resting state EC within seven large-scale networks, in 66 SZ and 74 healthy subjects from a public dataset. The results showed that a remarkable 33% of the effective connections (among subnetworks) of the cognitive control network had been pathologically modulated in SZ. Further dysconnection was identified within the visual, default mode and sensorimotor networks of SZ subjects, with 24%, 20%, and 11% aberrant couplings. Overall, the proportion of discriminative connections was remarkably larger in EC (24%) than FC (1%) analysis. Subsequently, to study the neural correlates of impaired cognition in SZ, we conducted a canonical correlation analysis between the EC parameters and the cognitive scores of the patients. As such, the self-inhibitions of supplementary motor area and paracentral lobule (in the sensorimotor network) and the excitatory connection from parahippocampal gyrus to inferior temporal gyrus (in the cognitive control network) were significantly correlated with the social cognition, reasoning/problem solving and working memory capabilities of the patients. Future research can investigate the potential of whole-brain EC as a biomarker for diagnosis of brain disorders and for neuroimaging-based cognitive assessment.
... The notion of agency has received much attention in research across numerous disciplines ranging from psychology (e.g., Aarts et al. 2005;Marcel 2003;Sato and Yasuda 2005) and philosophy (e.g., de Vignemont and Fourneret 2004;Eilan and Roessler 2003;Gallagher 2000Gallagher , 2004Pacherie 2007;Synofzik et al. 2008) to neuroscience (e.g., Chaminade and Decety 2002;Blakemore et al. 1999;Farrer et al. 2003;Tsakiris and Haggard 2005a) and psychopathology (e.g., Daprati et al. 1997;Franck et al. 2001;Frith et al. 2000;Stephens and Graham 2000). Gallagher (2007Gallagher ( , 2012 observes a lack of consensus regarding how agency is defined across these disciplines, noting that it is sometimes "construed in terms of bodily movement or motor control" and sometimes "linked to the intentional aspect of action" (2007,347). ...
This chapter asks what we know about the first-personal experience of ticcing and everyday action in people with Tourette Syndrome (TS) and other primary tic disorders. It notes a phenomenological vacuum in existing research on volition, which has investigated aspects of anomalous voluntary action in people living with these conditions without providing a clear picture of how such action is experienced by these subjects. Drawing on discussions of the multiple aspects of ‘agency’ and ‘ownership’ in philosophical phenomenology and phenomenological psychiatry, I use examples of involuntary action and schizophrenic alienation offered in the literature to explore what kind of experiential dynamics, or variations in experience, we might expect to find in primary tic disorders like TS. These considerations are juxtaposed with the existing experimental studies on agency and ownership in adults with TS (none of which investigate the experience of ticcing or extended everyday actions), with an eye to integrating this work into a broader phenomenological framework or psychopathology of primary tic disorders. The chapter concludes with a systematic overview of how agency and ownership dynamics may be studied in tic disorders and beyond and offers guiding questions for future research and practice.
... Converging evidence points to this area as a key player for monitoring the consistency between actions and their visual outcome (David et al., 2008). Further, the lateralization to the right PPC is compatible with previous neuroimaging evidence showing the prominent involvement of this region in the experience of controlling one's own actions, both in healthy individuals (Farrer et al., 2003) and in psychiatric and neurological patients affected by disorders of agency (Spence et al., 1997;Simeon et al., 2000). Indeed, damage to the right parietal hemisphere rather than the left one is associated not only to misattribution to one's own movements (Daprati et al., 2000), but to disturbances of other bodily selfconsciousness aspects as well (Berti et al., 2005;Arzy et al., 2006;Heydrich et al., 2010). ...
Visuo-motor integration shapes our daily experience and underpins the sense of feeling in control over our actions. The last decade has seen a surge in robotically and virtually mediated interactions, whereby bodily actions ultimately result in an artificial movement. But despite the growing number of applications, the neurophysiological correlates of visuo-motor processing during human-machine interactions under dynamic conditions remain scarce. Here we address this issue by employing a bimanual robotic interface able to track voluntary hands movement, rendered in real-time into the motion of two virtual hands. We experimentally manipulated the visual feedback in the virtual reality with spatial and temporal conflicts and investigated their impact on (1) visuo-motor integration and (2) the subjective experience of being the author of one's action (i.e., sense of agency). Using somatosensory evoked responses measured with electroencephalography, we investigated neural differences occurring when the integration between motor commands and visual feedback is disrupted. Our results show that the right posterior parietal cortex encodes for differences between congruent and spatially-incongruent interactions. The experimental manipulations also induced a decrease in the sense of agency over the robotically-mediated actions. These findings offer solid neurophysiological grounds that can be used in the future to monitor integration mechanisms during movements and ultimately enhance subjective experience during human-machine interactions.
... These findings suggest that self-efficacy may affect the physical and mental functioning in older people, and predictive factors may be closely associated with balance. If the expected outcome and self-efficacy are regarded as an image of the movement [22] and the perception of a sense of agency [23,24], respectively, the basis of brain function in creating a predictive factor of behavior that may affect balancing ability includes the neural activity of the right Inferior Parietal Lobe (IPL) and the Supplementary Motor Area (SMA). It is possible that predictive factors are established by cooperative activity between these brain regions via a neural connection. ...
Falls in older individuals can be caused by balance disorders, influenced by predictive factors based on self-efficacy and outcome expectation. This study investigated the relationship between predictive factors related to regional neural functional activity and postural control. We included 16 older men (average age, 76.4±5.8 years) and evaluated their balancing ability and fall-related selfefficacy using the Japanese version of Mini-Balance Evaluation Systems Test (J-Mini-BESTest) and the Japanese version of the Falls Efficacy Scale (JFES), respectively. We performed an electroencephalogram before, during, and after postural perturbations. The cortical activity in the right Inferior Parietal Lobe (IPL) and Supplementary Motor Area (SMA) was analyzed using current density in the specific regions of interest. Foot Response Values (FRV) were used to evaluate physical responses during postural perturbations. The neural activity values in the IPL after postural perturbations indicated a significant positive correlation with JFES and J-Mini-BESTest scores when prior information was provided to participants. The neural activity values in the SMA before postural perturbations showed a significant positive correlation with J-Mini-BESTest score and a significant negative correlation with FRV. Furthermore, during postural perturbations, subjects with prior information exhibited significant positive neural correlations with neural activity between the SMA and IPL. These results suggest that neural activity in these brain regions influence balancing ability and predictive factors. Prior knowledge of a postural perturbation’s timing could be a compensatory factor promoting the activation of predictive factors.
... A sense of agency can be also defined in terms of one's own personal control, but not in terms of the actions of others (Damen et al., 2015). The feeling of agency might be also activated by motor action on the level of neural processes (Farrer et al., 2003). In future research, it is worth taking a closer look at those diversities and controlling it. ...
The Dual Perspective Model introduces the agent and the recipient as two fundamental perspectives in social perception. The present study aimed to examine whether the experimental manipulations influence the agent and recipient perspectives (and agentic and communal self concepts) measured through questionnaires and control questions. In the agent perspective condition (N = 29), the participants pumped up an inflatable chair, and recalled the situation where they performed an action. In the recipient perspective condition (N = 29), the participants sit in an inflatable chair, keep their attention on the experienced sensations , and recall the situation when they were in the role of recipients. In the control condition (N = 32), the participants just sat. Then all the participants completed a scale assessing current perceptions of the agent and recipient perspectives, and agentic and communal self-concepts. In both experimental conditions, they also completed a few control questions. The agent perspective and agentic self-concept increased in the respondents in the agent perspective condition when compared to the two other conditions. No group differences for the recipient perspective and communal self-concepts were found. The implications of the activation of agentic self-perception are discussed.
... Functional hyperactivation in the right IPL and TPJ has been previously reported in subjects with schizophrenia during the performance of a task and has been associated with the severity of psychotic symptoms [96][97][98][99]. Indeed, the TPJ and the IPL, especially in the right hemisphere, have a crucial role in understanding the source of sensory events [100][101][102]. In particular, these regions are involved in self/other distinction, which is the ability to distinguish between the representations of our own and others' behaviors, experiences, and emotions [101,[103][104][105]. ...
The aim of the present study was to examine the neurobiological correlates of the two negative symptom domains of schizophrenia, the Motivational Deficit domain (including avolition, anhedonia, and asociality) and the Expressive Deficit domain (including blunted affect and alogia), focusing on brain areas that are most commonly found to be associated with negative symptoms in previous literature. Resting-state (rs) fMRI data were analyzed in 62 subjects affected by schizophrenia (SZs) and 46 healthy controls (HCs). The SZs, compared to the HCs, showed higher rs brain activity in the right inferior parietal lobule and the right temporoparietal junction, and lower rs brain activity in the right dorsolateral prefrontal cortex, the bilateral anterior dorsal cingulate cortex, and the ventral and dorsal caudate. Furthermore, in the SZs, the rs brain activity in the left orbitofrontal cortex correlated with negative symptoms (r = −0.436, p = 0.006), in particular with the Motivational Deficit domain (r = −0.424, p = 0.002), even after controlling for confounding factors. The left ventral caudate correlated with negative symptoms (r = −0.407, p = 0.003), especially with the Expressive Deficit domain (r = −0.401, p = 0.003); however, these results seemed to be affected by confounding factors. In line with the literature, our results demonstrated that the two negative symptom domains might be underpinned by different neurobiological mechanisms.
... The degree of sense of agency is closely linked to the activation of the right insula and the right pre-frontal areas (Farrer et al., 2003;Karnath et al., 2005), which are also crucial areas for anosognosia. These findings suggest a partial overlapping of awareness and sense of agency networks, which assures a realistic sense of agency for own actions and, if lesioned, underlies anosognosia. ...
Objectives
Anosognosic patients show a lack of awareness for their hemiplegia coupled with a distorted sense of agency for the actions performed by the plegic limbs. Since anosognosia is often associated with right brain damage, this hemisphere seems to play a dominant role in monitoring awareness for motor actions. Therefore, we would expect that anosognosic patients show distorted awareness and sense of agency also for actions performed with the unimpaired limb.
Method
To test this hypothesis, we induced illusory actions that could be congruent or incongruent with a preceding verbal command. A group of 16 right brain-damaged patients performed this task and then rated i) their ability to anticipate the actions, ii) their sense of agency and iii) their sense of ownership for each limb. Measures of awareness, neglect and motor impairment were also considered for the patient group.
Results
Following incongruent actions with the unimpaired limb, less aware patients showed a relatively mild distortion in all three aspects. In addition, we also found a crucial relationship between motor impairment (for the plegic limb) and sense of agency for both plegic and healthy limbs.
Conclusion
Although the distortion linked to both limbs supports the initial hypothesis that the right hemisphere is responsible for monitoring awareness for action for the whole body, our data also suggest that the observed distortion may be linked to a motor compensatory phenomenon, not necessarily related to awareness processes.
... Functionally, there have been recurrent reports about the reduced activation of SMA during motor and mental tasks (Crespo-Facorro et al., 1999;Guenther et al., 1994;Ortuno et al., 2005;Rogowska et al., 2004;Schröder et al., 1995) and a wide range of neurocognitive tasks in SZ (Picó-Pérez et al., 2022) and in early psychosis patients (Horne et al., 2022;Vanes et al., 2019). SMA dysfunction has also been associated with temporal processing deficit in SZ (as a measure of cognitive malfunction) (Alústiza et al., 2017;Davalos et al., 2011;Ortuño et al., 2011) and with reduced sense of agency (a common positive symptom of psychosis) (Farrer et al., 2003;Nachev et al., 2008;Wolpe et al., 2020;Yomogida et al., 2010). Our CCA analysis revealed that the self-inhibition of SMA at resting state is significantly correlated with the cognitive performance of SZ patients, above and beyond the other effective connections. ...
Schizophrenia (SZ) is a severe mental disorder characterized by failure of functional integration (aka dysconnection) across the brain. Recent functional connectivity (FC) studies have adopted functional parcellations to define subnetworks of large-scale networks, and to characterize the (dys)connection between them, in normal and clinical populations. While FC examines statistical dependencies between observations, model-based effective connectivity (EC) can disclose the causal influences that underwrite the observed dependencies. In this study, we investigated resting state EC between the subnetworks of seven large-scale networks, in 66 SZ and 74 healthy subjects from a public dataset. The results showed that a remarkable 33% of the effective connections (among subnetworks) of the cognitive control network had been pathologically modulated in SZ. Further dysconnection was identified within the visual, default mode and sensorimotor networks of SZ subjects, with 24%, 20% and 11% aberrant couplings. Overall, the proportion of diagnostic connections was remarkably larger in EC (24%) than FC (1%) analysis. Subsequently, to study the neural correlates of impaired cognition in SZ, we conducted a canonical correlation analysis between the EC parameters and the cognitive scores of the patients. As such, the self-inhibitions of supplementary motor area and paracentral lobule (in the sensorimotor network) and the excitatory connection from parahippocampal gyrus to inferior temporal gyrus (in the cognitive control network) were significantly correlated with the social cognition, reasoning/problem solving and working memory capabilities of the patients. Future research can investigate the potential of whole-brain EC as a biomarker for diagnosis of brain disorders and for cognitive assessment.
... That is, the results of movements are experienced as being self-caused if the predicted sensory feedback matches the actual sensory feedback; however, in case of mismatch, they are experienced as being generated externally 13 . In fact, SoA typically decreases with increasing temporal or spatial discrepancies between self-generated movements and their sensory feedback [14][15][16][17][18][19][20][21][22][23] . In recent years, there has been increasing interest in whether SoA changes with development or remains constant throughout life. ...
Along with the comparator model, the perception of action-outcome regularity is involved in the generation of sense of agency. In addition, the perception of action-outcome regularity is related to motor performance. However, no studies have examined the developmental changes in the perception of action-outcome regularity. The current study measured perceptual sensitivity to action-outcome regularity and manual dexterity in 200 children aged between 5 and 16 years. The results showed that perceptual sensitivity to action-outcome regularity was significantly lower in 5–6-year-old children than in 9–16-year-old children, and that it was significantly lower in children with low manual dexterity than in children with medium to high manual dexterity. Correlation analyses revealed significant correlations of age and perceptual sensitivity to action-outcome regularity, but no significant correlation of manual dexterity and perceptual sensitivity to action-outcome regularity, either overall or in any age band. The present study suggests that perceptual sensitivity to action-outcome regularity is immature at 5–6 years of age and that it may be impaired in 5–16-year-old children with poor manual dexterity.
... Functionally, there have been recurrent reports about the reduced activation of SMA during motor and mental tasks (Crespo-Facorro et al., 1999;Guenther et al., 1994;Ortuno et al., 2005;Rogowska et al., 2004;Schröder et al., 1995) and a wide range of neurocognitive tasks in SZ (Picó-Pérez et al., 2022) and in early psychosis patients (Horne et al., 2022;Vanes et al., 2019). SMA dysfunction has also been associated with temporal processing deficit in SZ (as a measure of cognitive malfunction) (Alústiza et al., 2017;Davalos et al., 2011;Ortuño et al., 2011) and with reduced sense of agency (a common positive symptom of psychosis) (Farrer et al., 2003;Nachev et al., 2008;Wolpe et al., 2020;Yomogida et al., 2010). Our CCA analysis revealed that the self-inhibition of SMA at resting state is significantly correlated with the cognitive performance of SZ patients, above and beyond the other effective connections. ...
Schizophrenia (SZ) is a severe mental disorder characterized by failure of functional integration (aka dysconnection) across the brain. Recent functional connectivity (FC) studies have adopted functional parcellations to define subnetworks of large-scale networks, and to characterize the (dys)connection between them, in normal and clinical populations. While FC examines statistical dependencies between observations, model-based effective connectivity (EC) can disclose the causal influences that underwrite the observed dependencies. In this study, we investigated resting state EC between the subnetworks of seven large-scale networks, in 66 SZ and 74 healthy subjects from a public dataset. The results showed that a remarkable 33% of the effective connections (among subnetworks) of the cognitive control network had been pathologically modulated in SZ. Further dysconnection was identified within the visual, default mode and sensorimotor networks of SZ subjects, with 24%, 20% and 11% aberrant couplings. Overall, the proportion of diagnostic connections was remarkably larger in EC (24%) than FC (1%) analysis. Subsequently, to study the neural correlates of impaired cognition in SZ, we conducted a canonical correlation analysis between the EC parameters and the cognitive scores of the patients. As such, the self-inhibitions of supplementary motor area and paracentral lobule (in the sensorimotor network) and the excitatory connection from parahippocampal gyrus to inferior temporal gyrus (in the cognitive control network) were significantly correlated with the social cognition, reasoning/problem solving and working memory capabilities of the patients. Future research can investigate the potential of whole-brain EC as a biomarker for diagnosis of brain disorders and for cognitive assessment.
... The somatosensory pathways are notoriously involved in both conscious perception/recognition of one's own body (i.e., body image) [162] and in the body schema construction [163], i.e., a dynamic representation of one's own body used to drive actions [164][165][166][167][168][169][170]. In addition, either the posterior insula or the angular gyrus also plays a significant role in integrating different input signals related to self-awareness in terms of enteroception, feelings of agency, and visceral sensations [171][172][173][174][175][176][177][178][179][180][181][182][183]. ...
Background:
The relationship binding body weight to psychological well-being is unclear. The present study aims at identifying the contribution, and specificity, of some dimensions (i.e., eating-related symptoms, body image disorders, eating habits, personality traits, and emotional difficulties) characterizing the psychological profile of obese adolescents (749 participants, 325 females; 58.3% normal-weight, 29.9% overweight, and 11.7% obese; mean age = 16.05, SD = 0.82).
Methods:
By introducing the scores obtained by standardized self-report tools into a generalized linear model, a factorial reduction design was used to detect the best fitting discriminant functions and the principal components explaining the higher proportion of the variance.
Results:
We found two discriminant functions correctly classifying 87.1% of normal-weight, 57.2% of overweight, and 68.2% of obese adolescents. Furthermore, two independent factors, explaining 69.68% of the total variance, emerged.
Conclusions:
The first factor, "Body Image Concerns", included the drive for thinness, body dissatisfaction, and interpersonal distrust. The second factor, "Selective Depersonalization", included a trend toward depersonalization and dissatisfaction with the torso. The neurophysiological implications of our findings will be discussed.
... This assumption is supported on several levels. The activation of specific cerebral areas that govern the attribution of the sources of an action to the self or to the other has been observed in tasks that involve direct imitation and in the imagining plans of action, thoughts and emotions, autobiographical memory, and attribution of personal pronouns (Decety and Ickes, 2009), and is reported to be inverted in certain subjects (such as those with schizophrenia), who show a deficit in holding a sense of ownership of their own actions and metal processes (Farrer et al., 2003). ...
The notion of intersubjectivity has achieved a primary status in contemporary psychoanalytic debate, stimulating new theoretical proposals as well as controversies. This paper presents an overview of the main contributions on inter-subjectivity in the field of neurosciences. In humans as well as—probably—in other species, the ability for emotional resonance is guaranteed early in development. Based on this capacity, a primary sense of connectedness is established that can be defined inter-subjective in that it entails sharing affective states and intentions with caregivers. We propose to define such a form of inter-subjectivity as contingent , since the infant’s early abilities for resonance do not imply the more generalized capacity to permanently conceive of the relationship outside the realm of current interactions and the infant-caregiver’s mutual correspondence of internal states. This form of connection, hence, results in a self-referential, bodily, and affectively codified, context- and time dependent, like-me experience of interactions. The gradual maturation of brain structures and processes as well as interactive experiences allow proper intersubjectivity exchanges, grounded on new intentional and representational capacities, to evolve. In this more mature form of intersubjectivity, the individual is allowed to conceive of her own psychic space both as distinct and as possibly connected with the other’s contents and experience, even in the absence of current behavioral indicators of such correspondence. This multi-layered model of intersubjectivity, which is embraced by current neuroscience research, seems to allow for new interpretations of psychoanalytic models of human relatedness based upon classic clinical observations.
Background
Sensory reafferents are crucial to correct our posture and movements, both reflexively and in a cognitively driven manner. They are also integral to developing and maintaining a sense of agency for our actions. In cases of compromised reafferents, such as for persons with amputated or congenitally missing limbs, or diseases of the peripheral and central nervous systems, augmented sensory feedback therefore has the potential for a strong, neurorehabilitative impact. We here developed an untethered vibrotactile garment that provides walking-related sensory feedback remapped non-invasively to the wearer’s back. Using the so-called FeetBack system, we investigated if healthy individuals perceive synchronous remapped feedback as corresponding to their own movement (motor awareness) and how temporal delays in tactile locomotor feedback affect both motor awareness and walking characteristics (adaptation).
Methods
We designed the system to remap somatosensory information from the foot-soles of healthy participants (N = 29), using vibrotactile apparent movement, to two linear arrays of vibrators mounted ipsilaterally on the back. This mimics the translation of the centre-of-mass over each foot during stance-phase. The intervention included trials with real-time or delayed feedback, resulting in a total of 120 trials and approximately 750 step-cycles, i.e. 1500 steps, per participant. Based on previous work, experimental delays ranged from 0ms to 1500ms to include up to a full step-cycle (baseline stride-time: µ = 1144 ± 9ms, range 986-1379ms). After each trial participants were asked to report their motor awareness.
Results
Participants reported high correspondence between their movement and the remapped feedback for real-time trials (85 ± 3%, µ ± σ), and lowest correspondence for trials with left-right reversed feedback (22 ± 6% at 600ms delay). Participants further reported high correspondence of trials delayed by a full gait-cycle (78 ± 4% at 1200ms delay), such that the modulation of motor awareness is best expressed as a sinusoidal relationship reflecting the phase-shifts between actual and remapped tactile feedback (cos model: 38% reduction of residual sum of squares (RSS) compared to linear fit, p < 0.001). The temporal delay systematically but only moderately modulated participant stride-time in a sinusoidal fashion (3% reduction of RSS compared a linear fit, p < 0.01).
Conclusions
We here demonstrate that lateralized, remapped haptic feedback modulates motor awareness in a systematic, gait-cycle dependent manner. Based on this approach, the FeetBack system was used to provide augmented sensory information pertinent to the user’s on-going movement such that they reported high motor awareness for (re)synchronized feedback of their movements. While motor adaptation was limited in the current cohort of healthy participants, the next step will be to evaluate if individuals with a compromised peripheral nervous system, as well as those with conditions of the central nervous system such as Parkinson’s Disease, may benefit from the FeetBack system, both for maintaining a sense of agency over their movements as well as for systematic gait-adaptation in response to the remapped, self-paced, rhythmic feedback.
Background
Dementia with Lewy bodies (DLB) is characterized by insular atrophy, which occurs at the early stage of the disease. Damage to the insula has been associated with disorders reflecting impairments of the most fundamental components of the self, such as anosognosia, which is a frequently reported symptom in patients with Lewy bodies (LB). The purpose of this study was to investigate modifications of the self-concept (SC), another component of the self, and to identify neuroanatomical correlates, in prodromal to mild DLB.
Methods
Twenty patients with prodromal to mild DLB were selected to participate in this exploratory study along with 20 healthy control subjects matched in terms of age, gender, and level of education. The Twenty Statements Test (TST) was used to assess the SC. Behavioral performances were compared between LB patients and control subjects. Three-dimensional magnetic resonance images (MRI) were acquired for all participants and correlational analyses were performed using voxel-based morphometry (VBM) in whole brain and using a mask for the insula.
Results
The behavioral results on the TST showed significantly impaired performances in LB patients in comparison with control subjects (p < .0001). Correlational analyses using VBM revealed positive correlations between the TST and grey matter volume within insular cortex, right supplementary motor area, bilateral inferior temporal gyri, right inferior frontal gyrus, and left lingual gyrus, using a threshold of p = .001 uncorrected, including total intracranial volume (TIV), age, and MMSE as nuisance covariates. Additionally, correlational analysis using a mask for the insula revealed positive correlation with grey matter volume within bilateral insular cortex, using a threshold of p = .005.
Conclusions
The behavioral results confirm the existence of SC impairments in LB patients from the prodromal stage of the disease, compared to matched healthy controls. As we expected, VBM analyses revealed involvement of the insula, among that of other brain regions, already known to be involved in other self-components. While this study is exploratory, our findings provide important insights regarding the involvement of the insula within the self, confirming the insula as a core region of the self-networks, including for high-order self-representations such as the SC.
The sense of embodiment refers to the sensations of being inside, having, and controlling a body. In virtual reality, it is possible to substitute a person’s body with a virtual body, referred to as an avatar. Modulations of the sense of embodiment through modifications of this avatar have perceptual and behavioural consequences on users that can influence the way users interact with the virtual environment. Therefore, it is essential to define metrics that enable a reliable assessment of the sense of embodiment in virtual reality to better understand its dimensions, the way they interact, and their influence on the quality of interaction in the virtual environment. In this review, we first introduce the current knowledge on the sense of embodiment, its dimensions (senses of agency, body ownership, and self-location), and how they relate the ones with the others. Then, we dive into the different methods currently used to assess the sense of embodiment, ranging from questionnaires to neurophysiological measures. We provide a critical analysis of the existing metrics, discussing their advantages and drawbacks in the context of virtual reality. Notably, we argue that real-time measures of embodiment, which are also specific and do not require double tasking, are the most relevant in the context of virtual reality. Electroencephalography seems a good candidate for the future if its drawbacks (such as its sensitivity to movement and practicality) are improved. While the perfect metric has yet to be identified if it exists, this work provides clues on which metric to choose depending on the context, which should hopefully contribute to better assessing and understanding the sense of embodiment in virtual reality.
Neuroelectric and imaging studies of meditation are reviewed. Electroencephalographic measures indicate an overall slowing subsequent to meditation, with theta and alpha activation related to proficiency of practice. Sensory evoked potential assessment of concentrative meditation yields amplitude and latency changes for some components and practices. Cognitive event-related potential evaluation of meditation implies that practice changes attentional allocation. Neuroimaging studies indicate increased regional cerebral blood flow measures during meditation. Taken together, meditation appears to reflect changes in anterior cingulate cortex and dorsolateral prefrontal areas. Neurophysiological meditative state and trait effects are variable but are beginning to demonstrate consistent outcomes for research and clinical applications. Psychological and clinical effects of meditation are summarized, integrated, and discussed with respect to neuroimaging data.
The a-normative posture of Hume’s Law, which posits that values and facts are irreconcilable, has posed a specific quandary for how value and physical reality are related, a relationship essential for bioethics, and one influencing neurotechnology praxis. The tension introduced by this question has been the subject of considerable conjecture by those concerned with the implications of its absence in nature. Among scholars like Hans Jonas and Karol Wojtyla (Pope John Paul II) the notion of a contingency that separates the individual, who is constituted by his body, from his worth introduces within nature a division between that which comprises the essence of physical reality, and the individual person, who is composed from this reality. Despite a prevailing mechanist understanding within modern neuroethics, emerging lines of thinking in philosophy of science and biological organization demonstrate a need for a revision in the grounding principles of these disciplines, which are more consonant with a retrieval of intrinsic value to the physical reality of the body. This revision is based on an instantiation of an autonomous self governance principle, a contemporary retrieval of Kantian thinking. In the context of neurotechnology praxis, this instantiation undergirds an intrinsic value content to brain and bodily organization. One consequence of this non-Humean understanding is the identification of normative boundaries with the physical analogues of the human body that give rise to his autonomy, which are preminent in the dynamic organization of the human brain.
The moving Rubber Hand Illusion (mRHI) is a paradigm which investigates the sense of ownership (SoO) and the sense of agency (SoA) towards an artificial hand. This study aimed to highlight the role of the SoA on the development of the SoO according to the information provided by an actionrelated auditory cue. We expected that a reinforcement of the SoO illusion by the SoA could not occur if the sound of the action was removed. In order to assess the SoO and SoA, 25 participants performed the task in the the active congruent, passive congruent, and active incongruent conditions. Also, the onset time of the SoO in the congruent conditions was reported. The results confirmed our hypothesis, showing that agency did not play a pivotal role in promoting the onset of the ownership illusion if ecological auditory feedback was removed. Further research on the cross-modal assessment of individual bodily selfconsciousness is recommended.
Sense of agency refers to the experience of controlling one’s actions and through them events in the outside world. General agency beliefs can be measured with the Sense of Agency Scale (SoAS), which consists of the sense of positive agency subscale (i.e., feeling of being in control over one’s own body, mind, and environment) and the sense of negative agency subscale (i.e., feeling existentially helpless). The aim of the present study was to validate a German version of the SoAS. Using factor analyzes, we replicated the two-factor structure of the original version of the SoAS. Further, the German SoAS showed good model fits, good internal consistency, and moderate test–retest reliability. Construct validity was supported by significant low to moderate correlations of the German SoAS with other conceptually similar, but still distinct constructs such as general self-efficacy. Additionally, the German SoAS has an incremental value in explaining variance in the extent of subclinical symptoms of schizotypal personality disorder that goes beyond variance explained by constructs that are conceptually similar to sense of agency. Taken together, the results indicate that the German SoAS is a valid and suitable instrument to assess one’s general agency beliefs.
Auditory hallucinations (AH) are a debilitating symptom in psychosis, impacting cognition and real world functioning. Recent thought conceptualizes AH as a consequence of long-range brain communication dysfunction, or circuitopathy, within the auditory sensory/perceptual, language, and cognitive control systems. Recently we showed in first-episode psychosis (FEP) that, despite overall intact white matter integrity in the cortical-cortical and cortical-subcortical language tracts and the callosal tracts connecting auditory cortices, the severity of AH correlated inversely with white matter integrity. However, that hypothesis-driven isolation of specific tracts likely missed important white matter concomitants of AH. In this report, we used a whole-brain data-driven dimensional approach using correlational tractography to associate AH severity with white matter integrity in a sample of 175 individuals. Diffusion Spectrum Imaging (DSI) was used to image diffusion distribution. Quantitative Anisotropy (QA) in three tracts was greater with increased AH severity (FDR < 0.001) and QA in three tracts was lower with increased AH severity (FDR < 0.01). White matter tracts showing associations between QA and AH were generally associated with frontal-parietal-temporal connectivity (tracts with known relevance for cognitive control and the language system), in the cingulum bundle, and in prefrontal inter-hemispheric connectivity. The results of this whole brain data-driven analysis suggest that subtle white matter alterations connecting frontal, parietal, and temporal lobes in the service of sensory-perceptual, language/semantic, and cognitive control processes impact the expression of auditory hallucination in FEP. Disentangling the distributed neural circuits involved in AH should help to develop novel interventions, such as non-invasive brain stimulation.
Distinguishing imagination and thoughts from information we perceived from the environment, a process called reality-monitoring, is important in everyday situations. Although reality monitoring seems to overlap with the concept of self-monitoring, which allows one to distinguish self-generated actions or thoughts from those generated by others, the two concepts remain largely separate cognitive domains and their common brain substrates have received little attention. We investigated the brain regions involved in these two cognitive processes and explored the common brain regions they share. To do this, we conducted two separate coordinate-based meta-analyses of functional magnetic resonance imaging studies assessing the brain regions involved in reality- and self-monitoring. Few brain regions survived threshold-free cluster enhancement family-wise multiple comparison correction (p < .05), likely owing to the small number of studies identified. Using uncorrected statistical thresholds recommended by Signed Differential Mapping with Permutation of Subject Images, the meta-analysis of reality-monitoring studies (k = 9 studies including 172 healthy subjects) revealed clusters in the lobule VI of the cerebellum, the right anterior medial prefrontal cortex and anterior thalamic projections. The meta-analysis of self-monitoring studies (k = 12 studies including 192 healthy subjects) highlighted the involvement of a set of brain regions including the lobule VI of the left cerebellum and fronto-temporo-parietal regions. We showed with a conjunction analysis that the lobule VI of the cerebellum was consistently engaged in both reality- and self-monitoring. The current findings offer new insights into the common brain regions underlying reality-monitoring and self-monitoring, and suggest that the neural signature of the self that may occur during self-production should persist in memories.
Body ownership and the sense of agency are two central aspects of bodily self-consciousness. While multiple neuroimaging studies have investigated the neural correlates of body ownership and agency separately, few studies have investigated the relationship between these two aspects during voluntary movement when such experiences naturally combine. By eliciting the moving rubber hand illusion with active or passive finger movements during functional magnetic resonance imaging, we isolated activations reflecting the sense of body ownership and agency, respectively, as well as their interaction, and assessed their overlap and anatomical segregation. We found that perceived hand ownership was associated with activity in premotor, posterior parietal and cerebellar regions, whereas the sense of agency over the hand’s movements was related to activity in the dorsal premotor cortex and superior temporal cortex. Moreover, one section of the dorsal premotor cortex showed overlapping activity for ownership and agency, and somatosensory cortical activity reflected the interaction of ownership and agency with higher activity when both agency and ownership were experienced. We further found that activations previously attributed to agency in the left insular cortex and right temporoparietal junction reflected the synchrony or asynchrony of visuo-proprioceptive stimuli rather than agency. Collectively, these results reveal the neural bases of agency and ownership during voluntary movement. Although the neural representations of these two experiences are largely distinct, there are interactions and functional neuroanatomical overlap during their combination, which has bearing on theories on bodily self-consciousness.
Learning the contingencies between a situational context (S), one's own responses (R), and their outcomes (O) and selecting responses according to their anticipated outcomes is the basis of a goal-directed behavior. Previous imaging studies found the angular gyrus (AG) to be correlated to both the representation of R-O associations and outcome-based response selection. Based on this correlational relationship, we investigated the causal link between AG function and goal-directed behavior in offline and online transcranial magnetic stimulation (TMS) experiments. To this end, we employed an experimental R-O compatibility paradigm testing outcome anticipation during response selection and S-R-O knowledge to probe S-R-O learning. In Experiment 1, we applied 1-Hz rTMS offline to the AG or the vertex before participants performed the experimental tasks. In Experiment 2, we applied online 10-Hz pulse trains to the AG or used sham stimulation during an early action selection stage in half of the trials. In both experiments, the R-O compatibility effect was unaltered when response selection was outcome-based, suggesting no causal role of the AG in outcome anticipation during response selection. However, in both experiments, groups with AG stimulation showed significantly modulated knowledge of S-R-O associations in a posttest. Additionally, in an explorative analysis, we found an induced R-O compatibility effect later in the experiment when response selection was guided by stimulus–response rules, suggesting reduced selectivity of outcome anticipation. We discuss possible compensatory behavioral and brain mechanism as well as specific TMS-related methodical considerations demonstrating important implications for further studies investigating cognitive function by means of TMS.
Background
The present study examines the relationship between obesity, executive functions, and body image in a nonclinical population from southern Italy.
Methods
General executive functioning (Frontal Assessment Battery–15), and body image disturbances (Body Uneasiness Test) were assessed in a sample including 255 participants (138 females, M age = 43.51 years, SD = 17.94, range = 18–86 years; M body mass index (BMI) = 26.21, SD = 4.32, range = 18.03–38.79).
Findings
Multiple Linear Regression Analysis indicated that age, years of education, FAB15 score, body image concerns, and avoidance predicted the variance of BMI. A subsequent mediation analysis highlighted that the indirect effect of FAB15 on BMI through avoidance was statistically significant.
Interpretation
Our results suggest that more performing executive functioning predicts a decrease in BMI that is partially due to the mitigation of avoidance behaviors.
The detection of object movement that is contingent on one’s own actions (i.e., movements with action contingency) influences social perception of the object; such interactive objects tend to create a good impression. However, it remains unclear whether neural representation of action contingency is associated with subsequent socio-cognitive evaluation of “contacting agents”, or whether the appearance of agents (e.g., face- or non-face-like avatars) is essential for this effect. In this study, we conducted a functional magnetic resonance imaging (fMRI) task with two phases: contact (contact with face- or non-face-like avatars moving contingently or non-contingently) and recognition (rating a static image of each avatar). Deactivation of the frontoparietal self-agency network and activation of the reward network were the main effects of action contingency during the contact phase, consistent with previous findings. During the recognition phase, static avatars that had previously moved in a contingent manner deactivated the frontal component of the frontoparietal network (bilateral insula and inferior-middle frontal gyri), regardless of person-like appearance. Our results imply that frontal deactivation may underlie the effect of action contingency on subsequent social perception, independent of person-like appearance.
Disagreements among phenomenologists about the notions of self and self-consciousness have been present from the very beginning. Some, including Husserl, defend egoic conceptions of consciousness; others like Gurwitsch and Sartre defend non-egoic conceptions. Merleau-Ponty and later phenomenologists provide for a notion of the embodied self. One general consensus, however, pertains to the notion of prereflective self-awareness and what is sometimes called the ‘minimal self’. The idea that prereflective self-awareness is a stable anchor for our experiences can be explained in terms of a Wittgensteinian concept which comes to be known as ‘immunity to error through misidentification’ (IEM). This chapter includes a review of some debates about IEM and looks at a variety of experiments and psychopathologies to understand whether this concept holds up to phenomenological scrutiny.
The problem of whether we can execute free acts or not is central in philosophical thought, and it has been studied by numerous scholars throughout the centuries. Recently, neurosciences have entered this topic contributing new data and insights into the neuroanatomical basis of cognitive processes. With the advent of connectomics, a more refined landscape of brain connectivity can be analysed at an unprecedented level of detail. Here, we identify the connectivity network involved in the movement process from a connectomics point of view, from its motivation through its execution until the sense of agency develops. We constructed a “volitional network” using data derived from the Brainnetome Atlas database considering areas involved in volitional processes as known in the literature. We divided this process into eight processes and used Graph Theory to measure several structural properties of the network. Our results show that the volitional network is small-world and that it contains four communities. Nodes of the right hemisphere are contained in three of these communities whereas nodes of the left hemisphere only in two. Centrality measures indicate the nucleus accumbens is one of the most connected nodes in the network. Extensive connectivity is observed in all processes except in Decision (to move) and modulation of Agency, which might correlate with a mismatch mechanism for perception of Agency.
The experience of willing an act arises from interpreting one's thought as the cause of the act. Conscious will is thus experienced as a function of the priority, consistency, and exclusivity of the thought about the action. The thought must occur before the action, be consistent with the action, and not be accompanied by other causes. An experiment illustrating the role of priority found that people can arrive at the mistaken belief that they have intentionally caused an action that in fact they were forced to perform when they are simply led to think about the action just before its occurrence.
Much information has been acquired on the anatomy and function of the insula over the past two decades. The insula has a dynamic cytoarchitectonic arrangement throughout its length. The anterior insula is comprised of an agranular allocortical area which functionally is part of the paralimbic belt. Its cortical connections are predominantly with other allocortical areas. Sub cortical, limbic, and brain stem connections underscore the anterior insula s role in processing and integrating autonomic and visceral information. The posterior insula is comprised of a granular isocortical area which functionally is linked to somatomotor systems. Its cortical connections are predominantly with other neocortical areas. Insular cortical and sub cortical connections, especially with the thalamus and basal ganglia, underscore the posteriorinsula s role in somatosensory, vestibular, and motor integration. The dysgranular insula lying in between the anterior and posterior insula represents an anatomical and functional transition between these regions. The predominant flow of intra insular projections from anterior to more posterior regions suggests that the posterior insula also serves as an integrative heteromodal association area for information received by all five senses. The insula plays a role in cardiovascular, gastrointestinal, vestibular, olfactory, gustatory, visual, auditory, somatosensory, and motor modulation. It is also felt to play a role in conditioned aversive learning, a ective and motivational components of pain perception, stress induced immunosuppression, mood stability, sleep, and language. Clinical correlation of damage to the insula, and the resultant impairment of the above functions is discussed.
Several recently developed philosophical approaches to the self promise to enhance
the exchange of ideas between the philosophy of the mind and the other cognitive
sciences. This review examines two important concepts of self: the ‘minimal self’, a self
devoid of temporal extension, and the ‘narrative self’, which involves personal identity
and continuity across time. The notion of a minimal self is first clarified by drawing a
distinction between the sense of self-agency and the sense of self-ownership for actions.
This distinction is then explored within the neurological domain with specific reference
to schizophrenia, in which the sense of self-agency may be disrupted. The convergence
between the philosophical debate and empirical study is extended in a discussion of
more primitive aspects of self and how these relate to neonatal experience and robotics.
The second concept of self, the narrative self, is discussed in the light of Gazzaniga’s
left-hemisphere ‘interpreter’ and episodic memory. Extensions of the idea of a narrative
self that are consistent with neurological models are then considered. The review
illustrates how the philosophical approach can inform cognitive science and suggests
that a two-way collaboration may lead to a more fully developed account of the self.
We report the case of a 50-year-old man (Mr PA) who sustained a right thalamic-temporo-parietal lesion resulting in severe hemispatial neglect and somatoparaphrenic delusions in the acute phase. One month after the lesion, Mr PA's ability to recognize his own movements was systematically analysed by means of an apparatus which allowed either the patient's or the examiner's moving hand to be displayed on a single screen. When viewing the examiner's hand, the patient saw a movement which was either identical (congruent condition) or different from his own (incongruent condition). In the latter conditions, both the examiner's and the patient's hand movements were synchronized in order to have the best match in both space and time. Since both hands were covered with identical gloves, attribution judgements could be produced only by comparing an internal representation of the executed movement to the visual image presented on the screen. When moving his contralesional hand, Mr PA systematically denied being the owner of the hand displayed on the screen, regardless of whether it was his own or the examiner's. Attribution errors were very frequent, and denial of ownership was associated with confabulatory behaviour. The behaviour of Mr PA was compared to that of four normal subjects and two neglect patients. In neither group did subjects present feeling of non-belonging towards their own hand, or confabulatory behaviour. In agreement with previous reports relating abnormal activity in the right parietal cortex and misattribution of the source of an action, we suggest that the behaviour of Mr PA is a consequence of a disorder of body awareness. More precisely, we propose that in the present case, the body-reference system was defective, thus inducing the patient to refuse ownership of the hand presented on the screen, even when it was actually his own.
We used positron emission tomography to contrast changes in cerebral blood flow associated with willed and routine acts. In the six tasks used, volunteers had to make a series of responses to a sequence of stimuli. For the routine acts, each response was completely specified by the stimulus. For the willed acts, the response was open-ended and therefore volunteers had to make a deliberate choice. Willed acts in the two response modalities studied (speaking a word, or lifting a finger) were associated with increased blood flow in the dorsolateral prefrontal cortex (Brodmann area 46). Willed acts were also associated with decreases in blood flow, but the location of these decreases was modality dependent.
We have used PET in conjunction with psychological activations to identify cortical areas involved in the intrinsic activation of word representations. In four normal subjects intrinsic generation of a word (verbal fluency) was associated with an increase in left dorsolateral prefrontal cortical activity (BA 46) and a bilateral decrease in activity in auditory and superior temporal cortices. Conversely, when subjects made lexical decisions about words that were heard, there was an increase in superior temporal activity with no change in area 46. We suggest that the superior temporal regions are the site of stored word representations and that inhibitory modulation of these areas by the left prefrontal cortex is the basis of intrinsic word generation.
Four patients are described who presented with a paroxysmal form of the alien hand syndrome. Two patients with damage to one frontomedial cortex had brief episodes of abnormal motor behaviour of the contralateral arm that featured groping, grasping, and apparently purposeful but perseverative movements, which both patients interpreted as alien or foreign. The other two patients, with posterior parietal damage, reported a paroxysmal feeling of unawareness of the location of the contralateral arm, lack of recognition of the arm as their own, purposeless movements, and personification of the arm. These cases represent a new form of the alien hand syndrome manifested by brief, paroxysmal episodes, which may be due to ictal mechanisms.
We studied the functional anatomy of affect-laden autobiographical memory in normal volunteers. Using H 2 ¹⁵ O positron emission tomography (PET), we measured changes in relative regional cerebral blood flow (rCBF). Four rCBF measurements were obtained during three conditions: REST, i.e., subjects lay at rest (for control); IMPERSONAL, i.e., subjects listened to sentences containing episodic information taken from an autobiography of a person they did not know, but which had been presented to them before PET scanning (nonautobiographical episodic memory ecphory); and PERSONAL, i.e., subjects listened to sentences containing information taken from their own past (autobiographical episodic memory ecphory).
Comparing IMPERSONAL with REST (nonautobiographical episodic memory ecphory) resulted in relative rCBF increases symmetrically in both temporal lobes including the temporal poles and medial and superior temporal gyri. The same loci, however, with a stronger lateralization to the right hemisphere were activated in the comparison PERSONAL to REST (autobiographical episodic memory ecphory). In addition, the right temporomesial, right dorsal prefrontal, right posterior cingulate areas, and the left cerebellum were activated. A comparison of PERSONAL and IMPERSONAL (autobiographical vs nonautobiographical episodic memory ecphory) demonstrated a preponderantly right hemispheric activation including primarily right temporomesial and temporolateral cortex, right posterior cingulate areas, right insula, and right prefrontal areas. The right temporomesial activation included hippocampus, parahippocampus, and amygdala.
These results suggest that a right hemispheric network of temporal, together with posterior, cingulate, and prefrontal, areas is engaged in the ecphory of affect-laden autobiographical information.
Schizophrenic patients experiencing passivity phenomena believe their thoughts and actions to be those of external, or alien, entities. We wished to test the hypothesis that voluntary motor action in such patients would be associated with aberrant patterns of activation within the cerebral motor system. We used H2(15)O PET to study patients while they performed paced joystick movements on two occasions 4-6 weeks apart. During the first scan passivity symptoms were maximal, while by the second scan these symptoms had significantly improved in five of the seven patients. Two control groups were also scanned on two occasions: deluded schizophrenic patients without passivity phenomena and normal subjects. In normal subjects, performance of freely selected joystick movements with the right hand, compared with rest, revealed relative activation of prefrontal, premotor, motor and parietal cortical regions. Schizophrenic patients with passivity showed hyperactivation of parietal and cingulate cortices. This hyperactivation remitted in those subjects in whom passivity decreased over time. This reversible hyperactivity was not a feature of schizophrenics without passivity. Given that these hyperactive cerebral regions subserve attention to internal and external bodily space, and the attribution of significance to sensory information, they provide a plausible anatomical substrate for the misattribution of internally generated acts to external entities: the cardinal feature of delusions of passivity (alien control).
Normal sensorimotor states involve integration of intention, action and sensory feedback. An example is the congruence between motor intention and sensory experience (both proprioceptive and visual) when we move a limb through space. Such goal-directed action necessitates a mechanism that monitors sensorimotor inputs to ensure that motor outputs are congruent with current intentions. Monitoring in this sense is usually implicit and automatic but becomes conscious whenever there is a mismatch between expected and realized sensorimotor states. To investigate how the latter type of monitoring is achieved we conducted three fully factorial functional neuroimaging experiments using PET measures of relative regional cerebral blood flow with healthy volunteers. In the first experiment subjects were asked to perform Luria's bimanual co-ordination task which involves either in-phase (conditions 1 and 3) or out-of-phase (conditions 2 and 4) bimanual movements (factor one), while looking towards their left hand. In half of the conditions (conditions 3 and 4) a mirror was used that altered visual feedback (factor two) by replacing their left hand with the mirror image of their right hand. Hence (in the critical condition 4) subjects saw in-phase movements despite performing out-of-phase movements. This mismatch between intention, proprioception and visual feedback engendered cognitive conflict. The main effect of out-of-phase movements was associated with increased neural activity in posterior parietal cortex (PPC) bilaterally [Brodmann area (BA) 40, extending into BA 7] and dorsolateral prefrontal cortex (DLPFC) bilaterally (BA 9/46). The main effect of the mirror showed increased neural activity in right DLPFC (BA 9/ 46) and right superior PPC (BA 7) only. Analysis of the critical interaction revealed that the mismatch condition led to a specific activation in the right DLPFC alone (BA 9/46). Study 2, using an identical experimental set-up but manipulating visual feedback from the right hand (instead of the left), subsequently demonstrated that this right DLPFC activation was independent of the hand attended. Finally, study 3 removed the motor intentional component by moving the subjects' hand passively, thus engendering a mismatch between proprioception and vision only. Activation in the right lateral prefrontal cortex was now more ventral than in studies 1 or 2 (BA 44/45). A direct comparison of studies 1 and 3 (which both manipulated visual feedback from the left hand) confirmed that a ventral right lateral prefrontal region is primarily activated by discrepancies between signals from sensory systems, while a more dorsal area in right lateral prefrontal cortex is activated when actions must be maintained in the face of a conflict between intention and sensory outcome.
A self-produced tactile stimulus is perceived as less ticklish than the same stimulus generated externally. We used fMRI to examine neural responses when subjects experienced a tactile stimulus that was either self-produced or externally produced. More activity was found in somatosensory cortex when the stimulus was externally produced. In the cerebellum, less activity was associated with a movement that generated a tactile stimulus than with a movement that did not. This difference suggests that the cerebellum is involved in predicting the specific sensory consequences of movements, providing the signal that is used to cancel the sensory response to self-generated stimulation.
The experience of willing an act arises from interpreting one's thought as the cause of the act. Conscious will is thus experienced as a function of the priority, consistency, and exclusivity of the thought about the action. The thought must occur before the action, be consistent with the action, and not be accompanied by other causes. An experiment illustrating the role of priority found that people can arrive at the mistaken belief that they have intentionally caused an action that in fact they were forced to perform when they are simply led to think about the action just before its occurrence.
The alien hand syndrome, as originally defined, was used to describe cases involving anterior corpus callosal lesions producing involuntary movement and a concomitant inability to distinguish the affected hand from an examiner's hand when these were placed in the patient's unaffected hand. In recent years, acceptable usage of the term has broadened considerably, and has been defined as involuntary movement occurring in the context of feelings of estrangement from or personification of the affected limb or its movements. Three varieties of alien hand syndrome have been reported, involving lesions of the corpus callosum alone, the corpus callosum plus dominant medial frontal cortex, and posterior cortical/subcortical areas. A patient with posterior alien hand syndrome of vascular aetiology is reported and the findings are discussed in the light of a conceptualization of posterior alien hand syndrome as a disorder which may be less associated with specific focal neuropathology than are its callosal and callosal-frontal counterparts.
Several recently developed philosophical approaches to the self promise to enhance the exchange of ideas between the philosophy of the mind and the other cognitive sciences. This review examines two important concepts of self: the 'minimal self', a self devoid of temporal extension, and the 'narrative self', which involves personal identity and continuity across time. The notion of a minimal self is first clarified by drawing a distinction between the sense of self-agency and the sense of self-ownership for actions. This distinction is then explored within the neurological domain with specific reference to schizophrenia, in which the sense of self-agency may be disrupted. The convergence between the philosophical debate and empirical study is extended in a discussion of more primitive aspects of self and how these relate to neonatal experience and robotics. The second concept of self, the narrative self, is discussed in the light of Gazzaniga's left-hemisphere 'interpreter' and episodic memory. Extensions of the idea of a narrative self that are consistent with neurological models are then considered. The review illustrates how the philosophical approach can inform cognitive science and suggests that a two-way collaboration may lead to a more fully developed account of the self.
The goal of this study was to assess brain glucose metabolism and its relationship to dissociation measures and clinical symptoms in DSM-IV depersonalization disorder.
Positron emission tomography scans coregistered with magnetic resonance images of eight subjects with depersonalization disorder were compared to those of 24 healthy comparison subjects. The two groups did not differ in age, sex, education, performance on a baseline neuropsychological battery, or performance on a verbal learning task administered during [(18)F]fluorodeoxyglucose uptake. A cortical analysis by individual Brodmann's areas was performed.
Compared to the healthy subjects, subjects with depersonalization disorder showed significantly lower metabolic activity in right Brodmann's areas 22 and 21 of the superior and middle temporal gyri and had significantly higher metabolism in parietal Brodmann's areas 7B and 39 and left occipital Brodmann's area 19. Dissociation and depersonalization scores among the subjects with depersonalization disorder were significantly positively correlated with metabolic activity in area 7B.
Depersonalization appears to be associated with functional abnormalities along sequential hierarchical areas, secondary and cross-modal, of the sensory cortex (visual, auditory, and somatosensory), as well as areas responsible for an integrated body schema. These findings are in good agreement with the phenomenological conceptualization of depersonalization as a dissociation of perceptions as well as with the subjective symptoms of depersonalization disorder.
The possibility that delusions of influence could be related to abnormal recognition of one's own actions was investigated in persons with schizophrenia.
Schizophrenic patients with (N=6) and without (N=18) delusions of influence were compared with normal subjects (N=29) on an action recognition task. The image of a virtual right hand holding a joystick was presented to the subjects through a mirror so that the image was superimposed on their real hand holding a real joystick. Subjects executed discrete movements in different directions. Angular biases and temporal delays were randomly introduced in some trials, such that the movement of the virtual hand departed from the movement executed by the subjects. After each trial, subjects were asked whether the movement they saw was their own.
Compared with normal subjects, both patient groups made significantly more recognition errors in trials with temporal delays. In trials with angular biases, the error rate of patients with delusions of influence significantly differed from that of comparison subjects and from that of patients without delusions of influence.
The findings support the hypothesis that delusions of influence are associated with a quantifiable difficulty in correct self-attribution of actions. This difficulty may be related to a specific impairment of a neural action attribution system.
Perspective taking is an essential component in the mechanisms that account for intersubjectivity and agency. Mental simulation of action can be used as a natural protocol to explore the cognitive and neural processing involved in agency. Here we took PET measurements while subjects simulated actions with either a first-person or a third-person perspective. Both conditions were associated with common activation in the SMA, the precentral gyrus, the precuneus and the MT/V5 complex. When compared to the first-person perspective, the third-person perspective recruited right inferior parietal, precuneus, posterior cingulate and frontopolar cortex. The opposite contrast revealed activation in left inferior parietal and somatosensory cortex. We suggest that the right inferior parietal, precuneus and somatosensory cortex are specifically involved in distinguishing self-produced actions from those generated by others.
Imitation is a natural mechanism involving perception-action coupling which plays a central role in the development of understanding that other people, like the self, are mental agents. PET was used to examine the hemodynamic changes occurring in a reciprocal imitation paradigm. Eighteen subjects (a) imitated the actions of the experimenter, (b) had their actions imitated by the experimenter, (c) freely produced actions, or (d) freely produced actions while watching different actions made by the experimenter. In a baseline condition, subjects simply watched the experimenter's actions. Specific increases were detected in the left STS and in the inferior parietal cortex in conditions involving imitation. The left inferior parietal is specifically involved in producing imitation, whereas the right homologous region is more activated when one's own actions are imitated by another person. This pattern of results suggests that these regions play a specific role in distinguishing internally produced actions from those generated by others.
The authors examined the severity of Schneiderian first-rank symptoms in relation to regional cerebral blood flow (rCBF) with the use of PET. Eighty-seven schizophrenic patients were imaged during an eyes-closed condition during which they were instructed to relax and not perform any specific task (random episodic silent thought, or REST). Schneiderian symptoms were rated by using structured assessment instruments. The Schneiderian score of the patients was positively correlated with rCBF in right superior parietal cortex and negatively correlated with rCBF in left posterior cingulate gyrus and in left lingual gyrus. The results of this study demonstrate a cerebral pattern of activation related to Schneiderian symptoms and reinforce the hypothesis of an involvement of cortical areas that mediate space and body representation in such phenomena.
This essay discusses new evidence supporting the concept that the distinct sensibilities for pain and temperature are based in part on specific ‘labeled lines’ that interact centrally as components of an ascending projection system subserving homeostasis and the generalized sense of the condition of the body itself (common sensation, or “Gemeingefühl”).
Schizophrenic patients experiencing passivity phenomena believe their thoughts and actions to be those of external, or alien, entities. We wished to test the hypothesis that voluntary motor action in such patients would be associated with aberrant patterns of activation within the cerebral motor system. We used H2(15)O PET to study patients while they performed paced joystick movements on two occasions 4-6 weeks apart. During the first scan passivity symptoms were maximal, while by the second scan these symptoms had significantly improved in five of the seven patients. Two control groups were also scanned on two occasions: deluded schizophrenic patients without passivity phenomena and normal subjects. In normal subjects, performance of freely selected joystick movements with the right hand, compared with rest, revealed relative activation of prefrontal, premotor, motor and parietal cortical regions. Schizophrenic patients with passivity showed hyperactivation of parietal and cingulate cortices. This hyperactivation remitted in those subjects in whom passivity decreased over time. This reversible hyperactivity was not a feature of schizophrenics without passivity. Given that these hyperactive cerebral regions subserve attention to internal and external bodily space, and the attribution of significance to sensory information, they provide a plausible anatomical substrate for the misattribution of internally generated acts to external entities: the cardinal feature of delusions of passivity (alien control).
We examined scalp-recorded event-related potentials following feedback stimuli in a time-estimation task. Six hundred msec after indicating the end of a 1 sec interval, subjects received a visual, auditory, or somatosensory stimulus that indicated whether the interval they had produced was correct. Following feedback indicating incorrect performance, a negative deflection occurred, whose characteristics corresponded closely to those of the component (the error-related negativity) that accompanies errors in choice reaction time tasks. Furthermore, equivalent dipole analysis suggested that, for all three modalities, the distribution of the scalp potential was consistent with a local source in the anterior cingulate cortex or a more distributed source in the supplementary motor areas. These loci correspond closely to those described previously for the error-related negativity. We conclude that the error-related negativity is the manifestation of the activity of a "generic" neural system involved in error detection.
This paper concerns the spatial and intensity transformations that map one image onto another. We present a general technique that facilitates nonlinear spatial (stereotactic) normalization and image realignment. This technique minimizes the sum of squares between two images following nonlinear spatial deformations and transformations of the voxel (intensity) values. The spatial and intensity transformations are obtained simultaneously, and explicitly, using a least squares solution and a series of linearising devices. The approach is completely noninteractive (automatic), nonlinear, and noniterative. It can be applied in any number of dimensions.
Various applications are considered, including the realignment of functional magnetic resonance imaging (MRI) time-series, the linear (affine) and nonlinear spatial normalization of positron emission tomography (PET) and structural MRI images, the coregistration of PET to structural MRI, and, implicitly, the conjoining of PET and MRI to obtain high resolution functional images.
Three-dimensional MRI imaging techniques offer new possibilities for qualitative and quantitative studies of gross neuroanatomy, functional neuroanatomy and for neurosurgical planning. The digital nature of the data allows for the reconstruction of realistic three-dimensional models of an individual brain which can be sliced at arbitrary orientations for optimal visual inspection of often complex neuroanatomy and pathology. This is particularly relevant in the assessment of potential neuroanatomical correlates of temporal lobe epilepsy. Re-formatting of contiguous thinly sliced (1–2 mm thick) volumetric MRI data along planes parallel and perpendicular to the temporal plane allow finer visual discrimination and greater standardisation in qualitative procedures than previously possible. Perhaps more exciting are the applications of quantitative analysis where, for instance, accurate measurements of hippocampus and/or amygdala volumes provide important indicators of unilateral mesial temporal sclerosis which compare favourably with EEG and more invasive methods of lateralising the epileptogenic focus (Jack et al., 1990; Cascino et al., 1991; Watson et al, 1992; Cendes et al., 1993 a,b). For instance, by combining volumetric measurements of both hippocampus and amygdala, Cendes et al., (Chapter 9) quote correct lateralisation of focus in 93 of 100 temporal lobe epilepsy cases. The study of epilepsy arising from cortical abnormalities has been limited in the past by the difficulties of visualising the cortical surface from a set of conventional two-dimensional MRI slices. New acquisition techniques with gradient echo as opposed to spin echo techniques allow for an improved signal-to-noise ratio in thin slices in times compatible with clinical examinations. Whole brain coverage with thin slice data is now possible, such that partial volume effects are minimised with consequent improvements in fine detail. Numerous authors have reported dramatic improvements in the assessment of cortical dysplasia and grey matter heterotopias, particularly for more subtle abnormalities (Palmini et al., 1991a,b,c; Barkovich and Kjos, 1992a,b,c). The impact of this improved raw data when combined with new techniques for generating three-dimensional surface renderings in reasonably interactive circumstances is yet to be fully realised but initial experience is promising. At present, most studies have relied upon visual inspection to identify abnormalities in gyration on three-dimensional surface-rendered MRI. Such methods are quite acceptable for gross pathologies but, in a manner similar to mesial temporal volumetrics, the identification of more subtle distortions may require quantitative analysis of left/right differences and comparison of individual gyral surface area or gyral/sulcal locations with previously established population norms. Cook et al., (Chapter 47) have approached the problem by application of fractal analysis to two-dimensional MRI images from normal and frontal lobe epilepsy (FLE) patients. The grey-white matter interface was extracted by image processing procedures as a continuous contour and the fractal dimension, an index of contour complexity, derived. Results indicate that 10 of 16 FLE patients had a fractal index more than 3 standard deviations (3SD) below normal. In its present form, the method provides a non-specific indicator of cortical abnormality, yielding an overall index of complexity rather than identifying specific abnormalities, and is implemented in two dimensions rather than three dimensions. Nevertheless, it illustrates the potential of quantitative analysis for detecting aberrant cortical morphology. For a more directed analysis of cortical folding, a model of normal neuroanatomical variability, expressed in three-dimensional coordinates, is necessary. Keyserlingk and co-workers have developed methods for digitising sulcal patterns from post-mortem brains and constructed a map, with cuboid elements of 4 mm or 8 mm edge length, of major sulcal anatomy from 30 such brains (Keyserlingk et al., 1983, 1985, 1988; Niemann et al, 1988). The advent of high resolution MRI scanning offers finer spatial and contrast resolution in normal brain in vivo. At the Montreal Neurological Institute, MRI and PET imaging techniques are combined with three-dimensional graphics and computational analysis in the study of functional neuroanatomy of cognitive and sensorimotor processing. As part of this “brain mapping” programme, we have collected a database of over 300 MRI volumes from young normal subjects and are presently engaged in a series of projects whose long-term goal is the construction of a probabilistic description of normal neuroanatomy derived from high-resolution (1 mm thick slices) MRI data. In this chapter we briefly describe the current brain mapping environment at our institute and the current development of the MRI atlas project in both volumetric and surface domains.
three types of disturbance of the body schema will be considered in this chapter: autotopagnosia, finger agnosia, and right–left disorientation (PsycINFO Database Record (c) 2012 APA, all rights reserved)
A severe multimodal neglect syndrome, mutism, oral apraxia and ideomotor apraxia for the right hand suddenly developed in a right-handed male following a right hemisphere (central) stroke. Neuropathologic examination showed an ischemic infarction involving the whole right insula, adjacent white matter, and the inner cortical surface of the right fronto-temporo-parietal operculum. The left hemisphere was spared. It is suggested that damage to the right insula (a polymodal convergence area), and the adjacent white matter may lead to severe neglect. Our case also demonstrates a clear dissociation between dominance for handedness and dominance for kinesthetic motor engrams.
A patient with a severe organic schizophreniform illness is described in whom the bizarre psychotic features were related to a non-dominant parietal lobe lesion. This case is a severe and unusual form of the neuro-psychiatric disorder, somatoparaphrenia. The relationship of this condition to other disorders of parietal lobe function is discussed.
We compared neuronal activity in the dorsal premotor cortex (PMd), ventral premotor cortex (PMv), and prefrontal (PF) cortex of two rhesus monkeys. The behavioral design was a variant of the instructed delay task which established that: (1) a given visual stimulus could, on different trials, instruct different limb movements and (2) several different visual stimuli could instruct the same movement. Neurons in all frontal areas displayed the often replicated activity patterns that occur during instructed delay tasks, including phasic increases after instruction stimuli (signal-related activity), tonic discharge during an instructed delay period (set-related activity), and phasic premovement discharge (movement-related activity). For signal-, set-, and movement-related activity, the majority of neurons in PMd (51-64%), but only a minority in PF (16-18%) and PMv (32-40%), showed activity levels that significantly depended on the action instructed by that stimulus rather than simply the characteristics of the stimulus per se. Thus, most PMd activity, including the aspects that most resembled a sensory response, reflected factors in addition to the signal. Taken together with the results of related studies, it seems most likely that these other factors are dominated by the motor instructional significance of the stimulus. In addition, many neurons (17-37%) in all examined areas showed activity that significantly depended on which of various stimuli guided the same movement. This finding shows that, in those frontal areas, neuronal activity can be affected by both the action to be taken and the events guiding that action.
We examined neuronal activity in three parts of the primate frontal cortex: the dorsal (PMd) and ventral (PMv) premotor cortex and a ventrolateral part of the dorsolateral prefrontal (PF) cortex. Two monkeys fixated a 0.2 degrees white square in the center of a video display while depressing a switch located between two touch pads. On each trial, a spatial-attentional/mnemonic (SAM) cue was presented first. The SAM cue consisted of one 2 degrees x 2 degrees square, usually red or green, and its location indicated where a conditional motor instruction would appear after a delay period. The stimulus event containing the motor instruction, termed the motor instructional/conditional (MIC) cue, could be of two general types. It might consist of a single 2 degrees x 2 degrees square stimulus identical to one of the SAM cues presented at the same location as the SAM cue on that trial. When the MIC cue was a single square, it instructed the monkey to move its forelimb to one of the two touch pads according to the following conditional rule: a green MIC cue meant that contact with the right touch pad would be rewarded on that trial and a red MIC cue instructed a movement to the left touch pad. Alternatively, the MIC cue might consist of two 2 degrees x 2 degrees squares, only one of which was at the SAM-cue location: in those cases, one square was red and the other was green. The colored square at the SAM cue location for that trial was the instructing stimulus, and the other part of the MIC cue was irrelevant. When, after a variable delay period, the MIC cue disappeared, the monkey had to touch the appropriate target within 1 s to receive a reward and could break visual fixation. The experimental design allowed comparison of frontal cortical activity when one stimulus, identical in retinocentric, craniocentric, and allocentric spatial location as well as all other stimulus parameters, had two different meanings for the animal's behavior. When a stimulus was the SAM cue, it led to either a reorientation of spatial attention to its location, or the storage of its location in spatial memory. By contrast, when it was the MIC cue, the same stimulus instructed a motor act to be executed after a delay period. For the majority of PMd neurons (55%), post-MIC cue activity exceeded post-SAM cue activity.(ABSTRACT TRUNCATED AT 400 WORDS)
The neural correlates of verbal self-monitoring were examined by measuring the response to alterations in auditory verbal feedback while subjects read aloud. Six normal subjects were studied with PET, using H2(15)O as a tracer of regional CBF. There was no difference between the temporal cortical response to reading aloud (and hearing one's own speech) and reading silently while hearing the words spoken by someone else. Distortion of subjects' speech (by pitch elevation) while they read aloud led to a bilateral activation of lateral temporal cortex, with a greater response on the right side than the left. A similar pattern of activation was evident when subjects read aloud, but the words they heard were spoken by someone else. These data suggest that (i) self-and externally generated speech are processed in similar regions of temporal cortex, and (ii) the monitoring of self-generated speech involves the temporal cortex bilaterally, in areas associated with the processing of speech which has been generated externally.
This paper introduces the concepts and procedures of "cognitive conjunction," a new approach to designing and analyzing cognitive activation experiments. Cognitive conjunction compliments categorical approaches such as cognitive subtraction and requires a specific form of statistical inference that involves the conjunction of several hypotheses. While cognitive subtraction studies are designed such that a pair of tasks differ only by the processing component(s) of interest, cognitive conjunction studies are designed such that two or more distinct task pairs each share a common processing difference. The neural correlates of the process of interest are then associated with the common areas of activation for each task pair. There are two main advantages of cognitive conjunction relative to cognitive subtraction. The first is that it provides a greater latitude for selecting baseline tasks because it is not necessary to control for all but the component of interest. The only constraint on selecting the baseline is that the component of interest is the only process that differs in each task pair. The second advantage is that cognitive conjunction does not depend on "pure insertion"--the assumption that the addition of an extra processing component in the activation task has no effect on the implementation of processes that are also engaged by the baseline task. The differences between the design and the statistical analysis of experiments based on cognitive subtraction, cognitive conjunction, and factorial designs are illustrated with a study of phonological retrieval. Cognitive conjunction analysis indicates that irrespective of whether subjects name words, objects, letters, or colors, there is activation of the left posterior basal temporal lobe, the left frontal operculum, the left thalamus, and the midline cerebellum.
This paper offers a framework for consciousness of internal reality. Recent PET experiments are reviewed, showing partial overlap of cortical activation during self-produced actions and actions observed from other people. This overlap suggests that representations for actions may be shared by several individuals, a situation which creates a potential problem for correctly attributing an action to its agent. The neural conditions for correct agency judgments are thus assigned a key role in self/other distinction and self-consciousness. A series of behavioral experiments that demonstrate, in normal subjects, the poor monitoring of action-related signals and the difficulty in recognizing self-produced actions are described. In patients presenting delusions, this difficulty dramatically increases and actions become systematically misattributed. These results point to schizophrenia and related disorders as a paradigmatic alteration of a "Who?" system for self-consciousness.
We studied the neural correlates of self vs. non-self judgements using functional magnetic resonance imaging (fMRI). Individually tailored faces and personality trait words were used as stimuli in three experiments (exp.). In the first two experiments, brain activation was measured while subjects viewed morphed versions of either their own (self face exp.) or their partner's face (partner's face exp.), alternating in blocks with presentation of an unknown face. In the self face exp. right limbic areas (hippocampal formation, insula, anterior cingulate), the right middle temporal lobe, left inferior parietal and left prefrontal regions showed signal changes. In the partner's face exp., only the right insula was activated. In the third exp., subjects made decisions about psychological trait adjectives previously categorized as describing their own attributes. Activation was present in the precuneus, the left parietal lobe, left insula/inferior frontal gyrus and the left anterior cingulate. A reaction time advantage was present when subjects responded to self-relevant words. The main area with signal changes during self-reference processing, regardless of the type of stimulus, was the left fusiform gyrus. The self-relevant stimuli engaged to a differential extent long term and working memory, semantic and emotional processes. We suggest that regions activated by these stimuli are engaged in self-processing.
We report two studies of facial self-perception using individually tailored, standardized facial photographs of a group of volunteers and their partners. A computerized morphing procedure was used to merge each target face with an unknown control face. In the first set of experiments, a discrimination task revealed a delayed response time for the more extensively morphed self-face stimuli. In a second set of experiments, functional magnetic resonance imaging (fMRI) was used to measure brain activation while subjects viewed morphed versions of either their own or their partner's face, alternating in blocks with presentation of an unknown face. When subjects viewed themselves (minus activation for viewing an unknown face), increased blood oxygenation was detected in right limbic (hippocampal formation, insula, anterior cingulate), left prefrontal cortex and superior temporal cortex. In the partner (versus unknown) experiment, only the right insula was activated. We suggest that a neural network involving the right hemisphere in conjunction with left-sided associative and executive regions underlies the process of visual self-recognition. Together, this combination produces the unique experience of self-awareness.
Inhibitory control and performance monitoring are critical executive functions of the human brain. Lesion and imaging studies have shown that the inferior frontal cortex plays an important role in inhibition of inappropriate response. In contrast, specific brain areas involved in error processing and their relation to those implicated in inhibitory control processes are unknown. In this study, we used a random effects model to investigate error-related brain activity associated with failure to inhibit response during a Go/NoGo task. Error-related brain activation was observed in the rostral aspect of the right anterior cingulate (BA 24/32) and adjoining medial prefrontal cortex, the left and right insular cortex and adjoining frontal operculum (BA 47) and left precuneus/posterior cingulate (BA 7/31/29). Brain activation related to response inhibition and competition was observed bilaterally in the dorsolateral prefrontal cortex (BA 9/46), pars triangularis region of the inferior frontal cortex (BA 45/47), premotor cortex (BA 6), inferior parietal lobule (BA 39), lingual gyrus and the caudate, as well as in the right dorsal anterior cingulate cortex (BA 24). These findings provide evidence for a distributed error processing system in the human brain that overlaps partially, but not completely, with brain regions involved in response inhibition and competition. In particular, the rostal anterior cingulate and posterior cingulate/precuneus as well as the left and right anterior insular cortex were activated only during error processing, but not during response competition, inhibition, selection, or execution. Our results also suggest that the brain regions involved in the error processing system overlap with brain areas implicated in the formulation and execution of articulatory plans.
We used H2(15)O PET to examine neural responses to parametrically varied degrees of discrepancy between the predicted and actual sensory consequences of movement. Subjects used their right hand to move a robotic arm. The motion of this robotic arm determined the position of a second foam-tipped robotic arm, which made contact with the subject's left palm. Using this robotic interface, computer controlled delays were introduced between the movement of the right hand and the tactile stimulation on the left. Activity in the right lateral cerebellar cortex showed a positive correlation with delay. These results suggest the cerebellum is involved in signalling the sensory discrepancy between the predicted and actual sensory consequences of movements.
Recent imaging studies of motor function provide new insights into the organization of the premotor areas of the frontal lobe. The pre-supplementary motor area and the rostral portion of the dorsal premotor cortex, the 'pre-PMd', are, in many respects, more like prefrontal areas than motor areas. Recent data also suggest the existence of separate functional divisions in the rostral cingulate zone.
The present study is aimed at identifying the neural correlates of two kinds of attribution: experiencing oneself as the cause of an action (the sense of agency) or experiencing another person as being the cause of that action. The experimental conditions were chosen so that they differed only in their requirement to attribute an action to another person or to oneself. The same motor task and the same visual stimuli were used in the experimental conditions. Subjects used a joystick to drive a circle along a T-shaped path. They were told that the circle would be driven either by themselves or by the experimenter. In the former case subjects were requested to drive the circle, to be aware that they drove the circle, and thus to mentally attribute the action seen on the screen to themselves. In the latter case they were also requested to perform the task, but they were aware that action seen on the screen was driven by the experimenter. In accord with previous studies, the results showed that being aware of causing an action was associated with activation in the anterior insula, whereas being aware of not causing the action and attributing it to another person was associated with activation in the inferior parietal cortex. These two regions are involved in the perception of complex representations of the self and of its interactions with the external world. We suggest that the anterior insula is concerned with the integration of all the concordant multimodal sensory signals associated with voluntary movements. The inferior parietal cortex, in contrast, represents movements in an allocentric coding system that can be applied to the actions of others as well as the self.
Recognizing oneself, easy as it appears to be, seems at least to require awareness of one's body and one's actions. To investigate the contribution of these factors to self-recognition, we presented normal subjects with an image of both their own and the experimenter's hand. The hands could make the same, a different or no movement and could be displayed in various orientations. Subjects had to tell whether the indicated hand was theirs or not. The results showed that a congruence between visual signals and signals indicating the position of the body is one component on which self-recognition is based. Recognition of one's actions is another component. Subjects had most difficulty in recognizing their hand when movements were absent. When the two hands made different movements, subjects relied exclusively on the movement cue and recognition was almost perfect. Our findings are in line with pathological alterations in the sense of body and the sense of action.
Coplanar Stereotaxic Atlas of the Human Brain Thieme Medical Sense of body and sense of action both contribute to self-recognition
- J Talairach
- P Tournoux
Talairach, J., Tournoux, P., 1988. Coplanar Stereotaxic Atlas of the Human Brain. Thieme Medical, New York. Van den Boos, E., Jeannerod, M., 2002. Sense of body and sense of action both contribute to self-recognition. Consciousness Cognition, in press.
- C Farrer
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Philosophical conceptions of the self
- Gallagher
Primate premotor cortex
- Boussaoud
Cerebral representations of one’s own past
- Fink
Anatomy of the insula—functional and clinical correlates
- Flynn