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Laterality index of brain activity during action observation . For participants with stroke (top), and nondisabled participants (bottom); during left-hand (gray bars) and right-hand (black bars) action observation, in regions of interest. Positive values indicate left hemisphere dominance; negative values indicate right hemisphere dominance.
Source publication
Mirror neurons found in the premotor and parietal cortex respond not only during action execution, but also during observation of actions being performed by others. Thus, the motor system may be activated without overt movement. Rehabilitation of motor function after stroke is often challenging due to severity of impairment and poor to absent volun...
Citations
... The clinical relevance of AOT has been scrutinized for its capacity to accelerate and improve functional recovery in stroke patients [34]. The rationale underlying this approach, grounded on the evidence that AOT increases the cortical excitability of motor brain areas [35], is that plastic processes can occur during action observation based on the mirror neuron system [36]. The SMR responses to the AO stimulus in section III.C also illustrated the cortical excitability of motor brain areas, which might benefit for rehabilitation. ...
Brain-computer interfaces (BCIs) are anticipated to improve the efficacy of rehabilitation for people with motor disabilities. However, applying BCI in clinical practice is still a challenge due to the great diversity of patients. In the current study, a novel action observation (AO) based BCI was proposed and tested on stroke patients. Ten non-hemineglect patients and ten hemineglect patients were recruited. Four AO stimuli were designed, each presenting a decomposed action to complete the reach-and-grasp task. EEG data and eye movement data were collected. Eye movement data was utilized to analyze the reasons for individual differences in BCI performance. Task discriminative component analysis was utilized to perform online target detection. The results showed that the designed AO-based BCI could simultaneously induce steady state motion visual evoked potential (SSMVEP) from the occipital region and sensory motor rhythm from the sensorimotor region in stroke patients. The average online detection accuracy among the four AO stimuli reached 67% within 3 s in the non-hemineglect group, while the accuracy only reached 35% in the hemineglect group. Gaze metrics showed that the average total duration of fixations during the stimulus phase in the hemineglect group was only 1.31 s ± 0.532 s which was significantly lower than that in the non-hemineglect group. The results indicated that hemineglect patients have difficulty gazing at the AO stimulus, resulting in poor detection performance and weak desynchronization in the sensorimotor region. Furthermore, the degree of neglect is inversely proportional to the target detection accuracy in hemineglect stroke patients. In addition, the gaze metrics associated with cognitive load were significantly correlated with the accuracy in non-hemineglect patients. It indicated the cognitive load may affect the AO-based BCI. The current study will expedite the clinical application of AO-based BCI.
... An ERP can be linked to a change in the EEG (not time-locked) that shows increased or reduced coordination of activity, labelled event-related desynchronization (ERD) or synchronization (ERS), respectively [6]. Notably, research on the mirror neuron system (MNS) has shown that the neurons that are activated during voluntary movements are also recruited during the observation of the same motor acts, with important neurophysiological and rehabilitation implications [7]. Specifically, so-called action-observation therapy leverages the MNS to promote motor recovery in people who are unable to perform movements adequately [8]. ...
... Specifically, so-called action-observation therapy leverages the MNS to promote motor recovery in people who are unable to perform movements adequately [8]. However, although the role of cortical areas in the MNS has been well characterised, the function of subcortical regions is less well understood, especially in the context of stroke [7,9]. Therefore, it seems very useful to evaluate the characteristics of these neurophysiological biomarkers during action observation (AO) in people with subcortical stroke. ...
... 14 In current psychological and clinical studies, the definition of visual imagery involves the self-visualization of action, whereas kinesthetic imagery implies somaesthetic sensations elicited by action. 15 A somewhat different distinction between kinesthetic and visual imagery relates MI to kinesthetic imagery of one"s own movements, whereas visual imagery is related to spatial coordinates of a movement within the environment. Thus, visual imagery applies mainly to the imagery of moving objects or to the movement of another person in the imagined environment, although imaging one"s own movement is additionally possible. ...
Background and Objectives: Bell's palsy is an acute-onset peripheral facial palsy and is the commonest cause for lower motor nerve fiber palsy. Facial resting symmetry and expressions are determining factors of facial attractiveness & being a marker of good health. The objective of study is to compare the effect of motor imagery and mirror book therapy versus mime therapy. There is dearth of evidence that proposes the effectiveness of motor imagery and mirror book therapy; mime therapy in improving the facial symmetry in acute Bell's palsy. Hence the need arises to evaluate the effectiveness of the motor imagery and mirror book therapy as compared to mime therapy on the recovery in Bell's palsy patients. Aim: To study the effect of motor imagery and mirror book therapy versus mime therapy for recovery in patients with acute Bell's palsy. Methodology: Convenient sampling was done for the selection of participants. Thirty participants who met the inclusion criteria were recruited from various hospitals of Vadodara. The participants were divided into three groups; Group A-Conventional electrotherapy along with Motor Imagery and Mirror book therapy; Group B-Mime therapy with conventional electrotherapy; Group C-Conventional electrotherapy with mirror bio-feedback exercises at home. Baseline data were collected with the use of SFGS and FDI. After 4 weeks, the participants were evaluated again. Result and conclusion: The data were analysed using the ANOVA test and there was a statistically greater improvement in Group A and Group B than the Group C with SFGS score. With FDI score the FDIS domain showed greater improvement in Group A than Group B and Group C. The SPSS version 23 used for data analysis and the p-value is 0.05.The present study concluded that Motor Imagery and Mirror Book Therapy, Mime therapy showed greater improvement in Facial Function and Facial Symmetry in patients with acute Bell's palsy. Motor Imagery and Mirror Book Therapy obtained better results regarding the quality of life and psychosocial functions than mime therapy and conventional electrotherapy.
... The efficacy of such MI/MO BCI training systems for neurorehabilitation strongly depends on the ability of the MI/MO tasks to elicit the desired patterns of motor-related brain activation [10,11]. In particular, the activation of the mirror neuron system (MNS) would be key to unravel the potential of MI/MO training systems for neurorehabilitation [12][13][14][15]. ...
Training motor imagery (MI) and motor observation (MO) tasks is being intensively exploited to promote brain plasticity in the context of post-stroke rehabilitation strategies. This may benefit from the use of closed-loop neurofeedback, embedded in brain-computer interfaces (BCI’s) to provide an alternative non-muscular channel, which may be further augmented through embodied feedback delivered through virtual reality (VR). Here, we used functional magnetic resonance imaging (fMRI) in a group of healthy adults to map brain activation elicited by an ecologically-valid task based on a VR-BCI paradigm called NeuRow, whereby participants perform MI of rowing with the left or right arm (i.e., MI), while observing the corresponding movement of the virtual arm of an avatar (i.e., MO), on the same side, in a first-person perspective. We found that this MI-MO task elicited stronger brain activation when compared with a conventional MI-only task based on the Graz BCI paradigm, as well as to an overt motor execution task. It recruited large portions of the parietal and occipital cortices in addition to the somatomotor and premotor cortices, including the mirror neuron system (MNS), associated with action observation, as well as visual areas related with visual attention and motion processing. Overall, our findings suggest that the virtual representation of the arms in an ecologically-valid MI-MO task engage the brain beyond conventional MI tasks, which we propose could be explored for more effective neurorehabilitation protocols.
... An emerging group of rehabilitation therapies has been proposed to improve motor function after disability by stroke (Faralli et al. 2013). Motor imagery training (MIT), which relies on repetitive mental practice of actions without overt movement or muscle activation, has been developed as an adjunctive therapy to restore lost motor function in stroke patients (Sharma et al. 2006;Garrison et al. 2010). Multiple studies have demonstrated that the brain regions activated during motor imagery tasks largely overlap with those involved in motor execution (Tong et al. 2017). ...
The efficacy of motor imagery training for motor recovery is well acknowledged, but with substantial inter-individual variability in stroke patients. To help optimize motor imagery training therapy plans and screen suitable patients, this study aimed to explore neuroimaging biomarkers explaining variability in treatment response. Thirty-nine stroke patients were randomized to a motor imagery training group (n = 22, received a combination of conventional rehabilitation therapy and motor imagery training) and a control group (n = 17, received conventional rehabilitation therapy and health education) for 4 weeks of interventions. Their demography and clinical information, brain lesion from structural MRI, spontaneous brain activity and connectivity from rest fMRI, and sensorimotor brain activation from passive motor task fMRI were acquired to identify prognostic factors. We found that the variability of outcomes from sole conventional rehabilitation therapy could be explained by the reserved sensorimotor neural function, whereas the variability of outcomes from motor imagery training + conventional rehabilitation therapy was related to the spontaneous activity in the ipsilesional inferior parietal lobule and the local connectivity in the contralesional supplementary motor area. The results suggest that additional motor imagery training treatment is also efficient for severe patients with damaged sensorimotor neural function, but might be more effective for patients with impaired motor planning and reserved motor imagery.
... Therefore, electrophysiological studies have provided extensive evidence for corticospinal reorganization after intervention with a program of stimulation of the mirror neurons [47]. This cortical reorganization achieved both by the virtual gait and the physical exercise program [48][49][50], would justify that in the EI there will be an improvement maintained up to 1 month after the end of the intervention. Despite the fact that people in EI group showed significant improvements on 2MWT and 5xSTS test, no differences between assessments were found on specific gait performance (i.e., vertical and medial-lateral range during gait and gait velocity), standing-up power and duration, and standing-to-sitting time. ...
Background
Virtual mirror therapies could increase the results of exercise, since the mirror neuron system produces an activation of motor execution cortical areas by observing actions performed by others. In this way, pre-frail and frail people could use this system to reach an exercise capacity threshold and obtain health benefits.
Aim
The aim of this study is to evaluate the effects of a virtual running (VR) treatment combined with specific physical gait exercise (PE) compared to placebo VR treatment combined with PE on functionality, pain, and muscular tone in pre-frail and frail older persons.
Methods
A single blinded, two-arm, randomised controlled trial design was employed. Thirty-eight participants were divided into two intervention arms: Experimental Intervention (EI) group, in which VR and gait-specific physical exercises were administered and Control Intervention (CI) group, in which a placebo virtual gait and the same exercise programme was administered. Functionality, pain, and tone were assessed.
Results
EI group improved in aerobic capacity, functional lower-limb strength, reaction time, and pain, while CI group remained the same. Regarding static balance and muscle tone, no differences were found for either group. Further analysis is needed to asses VR effectiveness for improving gait, stand-up and sit-down performance and velocity.
Conclusions
Virtual running therapy appears to enhance capacities related with voluntary movements (i.e., aerobic capacity, functional lower-limb strength, and reaction time) and reduce pain.
... Nojima et al. [14] confirmed by transcranial magnetic stimulation that the improvement of motor function after MT training was more associated with the remodeling of the major motor cortical areas. In MT training, constant visual and somatosensory stimulation could activate the MNS, induce neural remodeling [18,19], and cause upper motor function recovery. In addition, in MT, patients performed bilateral upper limb motor training independently or with assistance, and motor cortical areas were extensively activated when bilateral limbs performed symmetrical movements [20,21], and it can be assumed that mirror visual feedback could ease some of the motor pathways on the affected side and promote the recovery of limb motor function. ...
Background:
Rehabilitation of upper extremity hemiplegia after stroke remains a great clinical challenge, with only 20% of patients achieving a basic return to normal hand function. How to promote the recovery of motor function at an early stage is crucial to the life of the patient.
Objectives:
To invest the effects of additional mirror therapy in improving upper limb motor function and activities of daily living in acute and subacute stroke patients, and further explore the effects of other factors on the efficacy of MT.
Methods:
Participants who presented with unilateral upper extremity paralysis due to a first ischemic or hemorrhagic stroke were included in the study. They were randomly allocated to the experimental or control group. Patients in the control group received occupational therapy for 30 minutes each session, six times a week, for three weeks, while patients in the experimental group received 30 minutes of additional mirror therapy based on occupational therapy. The primary outcome measures were Fugl-Meyer Assessment-upper extremity (FMA-UE), Action Research Arm Test (ARAT), and Instrumental Activity of Daily Living (IADL) which were evaluated by two independent occupational therapists before treatment and after 3-week treatment. A paired t-test was used to compare the values between pretreatment and posttreatment within an individual group. Two-sample t-test was utilized to compare the changes (baseline to postintervention) between the two groups.
Results:
A total of 52 stroke patients with unilateral upper extremity motor dysfunction who were able to actively cooperate with the training were included in this study. At baseline, no significant differences were found between groups regarding demographic and clinical characteristics (P > 0.05 for all). Upper limb motor function and ability to perform activities of daily living of the patients were statistically improved in both groups towards the third week (P < 0.05). In addition, statistical analyses showed more significant improvements in the score changes of FMA-UE and IADL in the experimental group compared to the control group after treatment (P < 0.05), but no significant difference was observed in the ARAT score changes between the two groups (P > 0.05). The subgroup analysis showed that no significant heterogeneity was observed in age, stroke type, lesion side, and clinical stage (P > 0.05).
Conclusion:
In conclusion, some positive changes in aspects of upper limb motor function and the ability to perform instrumental activities of daily living compared with routine occupational therapy were observed in additional mirror therapy. Therefore, the application of additional mirror therapy training should be reconsidered to improve upper extremity motor in stroke patients.
... 11 Interestingly, research has shown that patients with severe stroke may benefit from 12 motor imagery (MI) and/or motor observation (MO) training through the use of 13 brain-computer interfaces (BCIs). BCI's can establish an alternative non-muscular 14 channel between the patient's brain activity and a computer, providing neurofeedback 15 in a closed-loop. This can be used to strengthen key motor pathways that are thought 16 to help promote brain plasticity mechanisms even in the absence of explicit 17 movement [6][7][8][9]. ...
... The efficacy of such MI/MO BCI training systems for 18 neurorehabilitation strongly depends on the ability of the MI/MO tasks to elicit the 19 desired patterns of motor-related brain activation [10,11]. In particular, the activation 20 of the mirror neuron system (MNS) would be key to unravel the potential of MI/MO 21 training systems for neurorehabilitation [12][13][14][15]. 22 A growing body of research evidences that concurrent MI and MO might be superior 23 to either condition alone in eliciting the desired brain activity [16][17][18][19][20]. ...
Training motor imagery (MI) and motor observation (MO) tasks is being intensively exploited to promote brain plasticity in the context of post-stroke rehabilitation strategies. The desired brain plasticity mechanisms may benefit from the use of closed-loop neurofeedback, embedded in brain-computer interfaces (BCIs) to provide an alternative non-muscular channel. These can be further augmented through embodied feedback delivered through virtual reality (VR). Here, we used functional magnetic resonance imaging (fMRI) to map brain activation elicited by a VR-based MI-MO BCI task called NeuRow and compared with a conventional non-VR, and MI-only, task based on the Graz BCI paradigm. We found that, in healthy adults, NeuRow elicits stronger brain activation when compared to the Graz task, as well as to an overt motor execution task, recruiting large portions of the parietal and occipital cortices in addition to the motor and premotor cortices. In particular, NeuRow activates the mirror neuron system (MNS), associated with action observation, as well as visual areas related with visual attention and motion processing. We studied a cohort of healthy adults including younger and older subgroups, and found no significant age-related effects in the measured brain activity. Overall, our findings suggest that the virtual representation of the arms in a bimanual MI-MO task engage the brain beyond conventional MI tasks, even in older adults, which we propose could be explored for effective neurorehabilitation protocols.
... The authors concluded that action observation has a positive impact on recovery of motor functions after stroke by reactivation of motor areas within the "action observation-action execution matching system", a network of cortical motor regions that are active when we perform an action and when we observe similar actions being performed by others (Rizzolatti & Craighero, 2004). In other words, action observation is hypothesized to rebuild motor function despite impairments by engaging similar brain regions to action execution (Garrison et al., 2010;Liew et al., 2012). Ryan et al., 2021). ...
For the past fifteen years, observation of actions has proved to be effective in the motor rehabilitation of stroke. Despite this, no evidence has ever been provided that this practice is able to activate the efferent motor system of a limb unable to perform the observed action due to stroke. In fact, transcranial magnetic stimulation cannot easily be used in these patients, and the fMRI evidence is inconclusive. This creates a logical problem, as the effectiveness of action observation in functional recovery is attributed to its ability to evoke action simulation, up to sub-threshold muscle activation (i.e., motor resonance), in healthy individuals. To provide the necessary proof-of-concept, patients with severe upper limb function impairments and matched control participants were submitted to a verified action prediction paradigm. They were asked to watch videos showing gripping movements towards a graspable or an ungraspable object, and to press a button the instant the agent touched the object. The presence of more accurate responses for the graspable object trials is considered an indirect evidence of motor resonance. Participants were required to perform the task in two sessions which differed in the hand used to respond. Despite the serious difficulty of movement, 8 out of 18 patients were able to perform the task with their impaired hand. We found that the responses given by the paretic hand showed a modulation of the action prediction time no different from that showed by the non-paretic hand, which, in turn, did not differ from that showed by the matched control participants. The present proof-of-concept study shows that action observation involves the efferent motor system even when the hand used to respond is unable to perform the observed action due to a cortical lesion, providing the missing evidence to support the already established use of Action Observation Training (AOT) in motor rehabilitation of stroke.
... This has led to the notion of an "extended MNS" including, among others, the sensorimotor areas [39], thus, providing an alternative or additional source of motor training that may be useful to promote recovery after stroke. [40]. ...
Electroencephalography-based Brain-Computer Interfaces (BCI's) can provide an alternative non-muscular channel of control to stroke survivors, especially to those who lack volitional movement. This is achieved through motor-imagery (MI) practice, involving the activation of motor-related brain regions. MI is reinforced in a closed-loop BCI through rewarding feedback, and it has been shown to be able to strengthen key motor pathways. Recently, growing evidence of the positive impact of virtual reality (VR) has accumulated. When combined with BCI, VR can provide patients with a safe simulated environment for rehabilitation training, which could be adapted to real-world scenarios. However, not all users have the ability to sufficiently modulate their brain activity for control of a MI-BCI, a problem known as BCI illiteracy. In this study, we investigate the role of embodied feedback and how we can help elderly adults increase their BCI performance during MI-BCI training in VR. The elderly population was selected to age-match with the typical stroke age-range demographic, accounting for age-related confounds. Participants have received MI-BCI training in two conditions: Abstract feedback (Graz BCI), and embodied feedback (NeuRow VR-BCI). Current results show differences between the two conditions in terms of Event-Related Desynchronization (ERD), lateralization of ERD and classifier performance in terms of arm discriminability.
