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© 1993
Nature
Publishing
Group
© 1993
Nature
Publishing
Group
© 1993
Nature
Publishing
Group
Spatial Working-memory In Humans As Revealed By Pet
Abstract
The concept of working memory is central to theories of human cognition because working memory is essential to such human skills as language comprehension and deductive reasoning. Working memory is thought to be composed of two parts, a set of buffers that temporarily store information in either a phonological or visuospatial form, and a central executive responsible for various computations such as mental arithmetic. Although most data on working memory come from behavioural studies of normal and brain-injured humans, there is evidence about its physiological basis from invasive studies of monkeys. Here we report positron emission tomography (PET) studies of regional cerebral blood flow in normal humans that reveal activation in right-hemisphere prefrontal, occipital, parietal and premotor cortices accompanying spatial working memory processes. These results begin to uncover the circuitry of a working memory system in humans.
... Studies have consistently indicated that the IFG is actively involved in multiple sensory and cognitive processes including a ention, working memory, and cognitive control [82][83][84]. Specifically, the IFG has been found to serve as an important component for spatial working memory processing, through its role in rapidly adapting a entional control to respond to current stimuli and retrieving stored information [85][86][87][88][89][90]. Further, studies involving EF tasks have ...
... Studies have consistently indicated that the IFG is actively involved in multiple sensory and cognitive processes including attention, working memory, and cognitive control [82][83][84]. Specifically, the IFG has been found to serve as an important component for spatial working memory processing, through its role in rapidly adapting attentional control to respond to current stimuli and retrieving stored information [85][86][87][88][89][90]. Further, studies involving EF tasks have characterized ADHD children as having long and variable RTs, with medium to large effect sizes [9,91,92]. ...
Attention deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder with high prevalence, heritability, and heterogeneity. Children with a positive family history of ADHD have a heightened risk of ADHD emergence, persistence, and executive function deficits, with the neural mechanisms having been under investigated. The objective of this study was to investigate working memory-related functional brain activation patterns in children with ADHD (with vs. without positive family histories (ADHD-F vs. ADHD-NF)) and matched typically developing children (TDC). Voxel-based and region of interest analyses were conducted on two-back task-based fMRI data of 362 subjects, including 186, 96, and 80 children in groups of TDC, ADHD-NF, and ADHD-F, respectively. Relative to TDC, both ADHD groups had significantly reduced activation in the left inferior frontal gyrus (IFG). And the ADHD-F group demonstrated a significant positive association of left IFG activation with task reaction time, a negative association of the right IFG with ADHD symptomatology, and a negative association of the IFG activation laterality index with the inattention symptom score. These results suggest that working memory-related functional alterations in bilateral IFGs may play distinct roles in ADHD-F, with the functional underdevelopment of the left IFG significantly informing the onset of ADHD symptoms. Our findings have the potential to assist in tailored diagnoses and targeted interventions in children with ADHD-F.
... Более выраженная реактивность мозгового кровотока правого полушария во время задач зрительно-пространственной памяти коррелировала с результатами нейровизуализационных исследований головного мозга. Например, с помощью ПЭТ была показана правосторонняя активация различных структур коры во время процессов зрительнопространственной памяти [24]. ...
... That limit, of about seven (plus or minus two), has since figured prominently in information-processing theories (e.g., Baddeley, 1986Baddeley, , 1992Just & Carpenter, 1992;Shiffrin, 1976), as captured in the following quote: "We are aware today of the centrality of short-term memory limits to performance in many, if not most cognitive tasks, and have long used George Miller's seven chunks to characterize those limits" (Simon, 1990, pp. 16-17). Moreover, neuroimaging studies (Jonides et al., 1993(Jonides et al., , 1996Just, Carpenter, & Keller, 1996;Just, Carpenter, Keller, Eddy, & Thulborn, 1996;Smith & Jonides, 1997) have demonstrated the reality of both structural and processing aspects of working memory. Still, whereas the magic number seven itself has become a cornerstone of cognitive psychology, 1 the question of "why seven?"-that is, are samples of that size of some benefit to cognitive functioning, or is limited capacity never anything but a liability-has seldom been raised. ...
Capacity limitations of working memory force people to rely on samples consisting of 7 ± 2 items. The implications of these limitations for the early detection of correlations between binary variables were explored in a theoretical analysis of the sampling distribution of φ, the contingency coefficient. The analysis indicated that, for strong correlations (φ > .50), sample sizes of 7 ± 2 are most likely to produce a sample correlation that is more extreme than that of the population. Another analysis then revealed that there is a similar cutoff point at which useful correlations (i.e., for which each variable is a valid predictor of the other) first outnumber correlations for which this is not the case. Capacity limitations are thus shown to maximize the chances for the early detection of strong and useful relations.
Memory for words that are drawn or sketched by the participant, rather than written, during encoding is typically superior. While this drawing benefit has been reliably demonstrated in recent years, there has yet to be an investigation of its neural basis. Here, we asked participants to either create drawings, repeatedly write, or list physical characteristics depicting each target word during encoding. Participants then completed a recognition memory test for target words while undergoing functional magnetic resonance imaging (fMRI). Behavioural results showed memory was significantly higher for words drawn than written, replicating the typical drawing effect. Memory for words whose physical characteristics were listed at encoding was also higher than for those written repeatedly, but lower than for those drawn. Voxel-wise analyses of fMRI data revealed two distributed sets of brain regions more active for items drawn relative to written, the left angular gyrus (BA 39) and bilateral frontal (BA 10) regions, suggesting integration and self-referential processing during retrieval of drawn words. Brain-behaviour correlation analyses showed that the size of one’s memory benefit for words drawn relative to written at encoding was positively correlated with activation in brain regions linked to visual representation and imagery (BA 17 and cuneus) and motor planning (premotor and supplementary motor areas; BA 6). This study suggests that drawing benefits memory by coactivating multiple sensory traces. Target words drawn during encoding are subsequently remembered by re-engaging visual, motoric, and semantic representations.
Much has been discussed about the Theory of Mind (ToM) and language. Some authors suggest that activating one enlightens the other, while others view language merely as a tool for developing the most distinctly human ability known. When it comes to speech and communication disorders, tracing ToM can be challenging since patients lack the tools to demonstrate their cognitive performance. This chapter delves into the biological foundations of ToM (anatomical and neurochemical). It also explores the evolution of ToM and neuroplasticity along our lifespan so that the reader can understand that nothing is static, that our brain engages in an everlasting dynamic relationship to keep us healthy and safe. This understanding has significant implications in how we approach language pathologies and the cognitive decline they might hinder. Additionally, the chapter examines the pragmatic side of language, offering insights into the right hemisphere and its role in emotion and affective communication. It considers the production-perception loop in communication, acknowledging that language and cognition cannot always be solely measured from production or perception alone. Social, cultural, and pathological factors may intervene and disrupt this loop, prompting the need for careful consideration in ToM theories and methods, particularly in the context of language pathologies. All these considerations should not be considered as preliminary or complementary, but central in understanding the implications of language in ToM, what language must really entail, so that the best clinical assessment and intervention is possible for patients with language pathologies. Finally, the chapter blends all these analyses into offering a review of crucial aspects of ToM in patients with aphasia.
Objective
Childhood sexual abuse is the leading cause of posttraumatic stress disorder (PTSD) in women, and is a prominent cause of morbidity and loss of function for which limited treatments are available. Understanding the neurobiology of treatment response is important for developing new treatments. The purpose of this study was to assess neural correlates of personalized traumatic memories in women with childhood sexual abuse with and without PTSD, and to assess response to treatment.
Methods
Women with childhood sexual abuse with (N = 28) and without (N = 17) PTSD underwent brain imaging with High-Resolution Positron Emission Tomography scanning with radiolabeled water for brain blood flow measurements during exposure to personalized traumatic scripts and memory encoding tasks. Women with PTSD were randomized to paroxetine or placebo followed by three months of double-blind treatment and repeat imaging with the same protocol.
Results
Women with PTSD showed decreases in areas involved in the Default Mode Network (DMN), a network of brain areas usually active when the brain is at rest, hippocampus and visual processing areas with exposure to traumatic scripts at baseline while women without PTSD showed increased activation in superior frontal gyrus and other areas (p < 0.005). Treatment of women with PTSD with paroxetine resulted in increased anterior cingulate activation and brain areas involved in the DMN and visual processing with scripts compared to placebo (p < 0.005).
Conclusion
PTSD related to childhood sexual abuse in women is associated with alterations in brain areas involved in memory and the stress response and treatment with paroxetine results in modulation of these areas.
The prefrontal cortex is so important to human beings that, if deprived of it, our behavior is reduced to action-reactions and automatisms, without the ability to make deliberate decisions. Why does the prefrontal cortex hold such importance in humans? To answer this question, this review will draw on the proximity between humans and other primates allowing us, through comparative anatomical-functional analysis, to understand the cognitive functions that we have in common but also to specify those that distinguish humans from their closest cousins.
First, the focus will be on the lateral region of the prefrontal cortex to illustrate the existence of a continuum between rhesus monkeys (the most studied primates in neuroscience) and humans for most of the major cognitive functions for which this region of the brain plays a central role. This continuum involves the presence of elementary mental operations in the rhesus monkey (e.g., working memory or response inhibition) constitutive of “macro-functions” such as planning, problem-solving, and even language production.
Second, the human prefrontal cortex has developed dramatically compared to that of other primates. This increase seems to concern the most anterior part (the frontopolar cortex). In humans, the development of the most anterior prefrontal cortex is associated with three major and interrelated cognitive changes: i/ greater working memory capacities allowing for a greater integration of past experiences and prospective future; ii/ a greater capacity to link discontinuous or distant data, whether temporal or semantic; iii/ a greater capacity for abstraction allowing humans to classify knowledge in different ways to engage in analogical reasoning or to acquire abstract values that give rise to our beliefs and morals. Together, these new skills enable us, among other things, to develop highly sophisticated social interactions based on language, to dematerialise the world in order to conceive beliefs and moral judgements, and to conceptualise, create and extend our vision of our environment beyond what we can physically grasp. Finally, a model of the transition of the prefrontal functions between human and non-human primates will conclude this review.
A full understanding of the biology and behavior of humans cannot be complete without the collective contributions of the social sciences, cognitive sciences, and neurosciences. This book collects eighty-two of the foundational articles in the emerging discipline of social neuroscience.
The book addresses five main areas of research: multilevel integrative analyses of social behavior, using the tools of neuroscience, cognitive science, and social science to examine specific cases of social interaction; the relationships between social cognition and the brain, using noninvasive brain imaging to document brain function in various social situations; rudimentary biological mechanisms for motivation, emotion, and attitudes, and the shaping of these mechanisms by social factors; the biology of social relationships and interpersonal processes; and social influences on biology and health.
Bradford Books imprint
The psychobiology of metacognition is a vast field of investigation despite being rarely conclusively demonstrated in many species. This chapter explores the interconnectedness of metacognition through the lens of psychology and biology. It delves into the evolutionary, historical, neurological, and psychological aspects of human self-reflection and the ability to comprehend the workings of one’s own mind. The chapter presents a comprehensive analysis of the various dimensions that contribute to our understanding of metacognition.
Three studies with 9 rhesus monkeys examined whether removal of the tissue of sulcus principalis affected Ss' memory for a list of spatial locations. Findings show that 3 Ss whose tissue in the sulcus principalis had been removed were no longer able to search effectively for food, relative to 3 unoperated controls, when given 25 spatial locations to remember. A less marked deficit was apparent in 3 Ss whose superior prefrontal convexity had been removed. Ss with sulcus principalis lesions learned as quickly as other Ss to choose between locations on the basis of a spatial cue, and they did not take significantly longer to shift from a previously rewarded location. Findings are considered in relation to the deficits observed in humans with unilateral frontal lesions and the possibility that frontal mechanisms operate on information in working memory. (55 ref)
Two experiments, with 64 undergraduates, demonstrated that individual differences in working memory capacity affected the probability of resolving apparent inconsistencies within sentences. Resolution was less likely for Ss with small working memories, as assessed by a reading span test that taxed both processing and storage functions. It is suggested that Ss with small spans devoted so many resources to reading processes that they had less capacity for retaining earlier verbatim wording in working memory. Ss with small spans had particular difficulty recovering from inconsistencies when a sentence boundary intervened, which suggests that end-of-sentence processes taxed the poor reader more. Reading times were used to model the time course of integration. Detection and recovery increased processing time. Furthermore, detection was apparent on the first inconsistent word, suggesting that Ss attempted to integrate a word immediately and did not buffer several words before processing them semantically. (62 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
The existence and neuroanatomical locations of separate extrastriate visual pathways for object recognition and spatial localization were investigated in healthy young men. Regional cerebral blood flow was measured by positron emission tomography and bolus injections of H2(15)O, while subjects performed face matching, dot-location matching, or sensorimotor control tasks. Both visual matching tasks activated lateral occipital cortex. Face discrimination alone activated a region of occipitotemporal cortex that was anterior and inferior to the occipital area activated by both tasks. The spatial location task alone activated a region of lateral superior parietal cortex. Perisylvian and anterior temporal cortices were not activated by either task. These results demonstrate the existence of three functionally dissociable regions of human visual extrastriate cortex. The ventral and dorsal locations of the regions specialized for object recognition and spatial localization, respectively, suggest some homology between human and nonhuman primate extrastriate cortex, with displacement in human brain, possibly related to the evolution of phylogenetically newer cortical areas.
Statistical parametric maps (SPMs) are potentially powerful ways of localizing differences in regional cerebral activity. This potential is limited by uncertainties in assessing the significance of these maps. In this report, we describe an approach that may partially resolve this issue. A distinction is made between using SPMs as images of change significance and using them to identify foci of significant change. In the first case, the SPM can be reported nonselectively as a single mathematical object with its omnibus significance. Alternatively, the SPM constitutes a large number of repeated measures over the brain. To reject the null hypothesis, that no change has occurred at a specific location, a threshold adjustment must be made that accounts for the large number of comparisons made. This adjustment is shown to depend on the SPM's smoothness. Smoothness can be determined empirically and be used to calculate a threshold required to identify significant foci. The approach models the SPM as a stationary stochastic process. The theory and applications are illustrated using uniform phantom images and data from a verbal fluency activation study of four normal subjects.
The cognitive processes in a widely used, nonverbal test of analytic intelligence, the Raven Progressive Matrices Test (Raven, 1962), are analyzed in terms of which processes distinguish between higher scoring and lower scoring subjects and which processes are common to all subjects and all items on the test. The analysis is based on detailed performance characteristics, such as verbal protocols, eye-fixation patterns, and errors. The theory is expressed as a pair of computer simulation models that perform like the median or best college students in the sample. The processing characteristic common to all subjects is an incremental, reiterative strategy for encoding and inducing the regularities in each problem. The processes that distinguish among individuals are primarily the ability to induce abstract relations and the ability to dynamically manage a large set of problem-solving goals in working memory.
The term working memory refers to a brain system that provides temporary storage and manipulation of the information necessary
for such complex cognitive tasks as language comprehension, learning, and reasoning. This definition has evolved from the
concept of a unitary short-term memory system. Working memory has been found to require the simultaneous storage and processing
of information. It can be divided into the following three subcomponents: (i) the central executive, which is assumed to be
an attentional-controlling system, is important in skills such as chess playing and is particularly susceptible to the effects
of Alzheimer's disease; and two slave systems, namely (ii) the visuospatial sketch pad, which manipulates visual images and
(iii) the phonological loop, which stores and rehearses speech-based information and is necessary for the acquisition of both
native and second-language vocabulary.
Since the 1960s, there has been controversy as to whether long-term learning might depend on some form of temporary short-term storage. Evidence that patients with grossly impaired memory span might show normal learning was, however, particularly problematic for such views. We reexamine the question by studying the learning capacity of a patient, P.V., with a very pure deficit in short-term memory. A series of experiments compare her learning capacity with that of matched controls. The first experiment shows that her capacity to learn pairs of meaningful words is within the normal range. A second experiment examines her capacity to learn to associate a familiar word with an unfamiliar item from another language. With auditory presentation she is completely unable to perform this task. Further studies show that when visual presentation is used she shows evidence of learning, but is clearly impaired. It is suggested that short-term phonological storage is important for learning unfamiliar verbal material, but is not essential for forming associations between meaningful items that are already known. Implications for the possible role of a phonological short-term store in the acquisition of vocabulary by children are discussed.