[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-detail-120638-en":3,"doc-seo-120638-105":29,"detail-sidebar-cat-0-en-105":89},{"code":4,"msg":5,"data":6},0,"success",{"doc_id":7,"user_id":8,"nickname":9,"user_avatar":10,"doc_module":4,"category_id":11,"category_name":12,"doc_title":13,"doc_description":14,"doc_content":15,"file_id":16,"file_url":17,"file_type":18,"file_size":19,"view_count":4,"is_deleted":4,"is_public":20,"is_downloadable":20,"audit_status":20,"page_count":20,"language":21,"language_code":22,"site_id":23,"html_lang":22,"table_of_contents":24,"faqs":25,"seo_title":26,"seo_description":14,"update_tm":27,"read_time":28},120638,7971461741311,"Ophelia","https://ap-avatar.wpscdn.com/avatar/74000253aff267980c6?x-image-process=image/resize,m_fixed,w_180,h_180&k=1779345379180704826",8,"Research & Report","A Neurocomputational Model of Impaired Imitation - Research Presentation","A Neurocomputational Model of Impaired Imitation investigates how visuomotor imitation and learning are supported by cognitive and neural mechanisms. The approach builds a neuroanatomically inspired network constrained by brain lesion, imaging, and neurophysiological evidence, proposing left-lateralized computation and hemisphere-specific information flow. The model identifies key activated regions, defines time and multimodal processing using leaky integrator neurons and learned sensory weights, and simulates probabilistic lesions. Parameters are fitted to imitation data from classic studies, and predictions link lesion severity with processing time while suggesting face-part and spatial error shifts.","metadata, citation and similar [papers at ](papers at core.ac.uk)[core.ac.uk](papers at core.ac.uk)  \nA Neurocomputational Model of Impaired Imitation  \nBiljana Petreska & Aude Billard  \nLASA Laboratory, Ecole Polytechnique Fédérale de Lausanne , EPFL  \n[http://lasa.epfl.ch](http://lasa.epfl.ch)  \nprovided by Infoscience- École polytechnique fédérale de Lau  \nMotivations and Approach  \n▪ To understand the basic cognitive and neural mechanisms underlying visuomotor imitation and learning through observation.  \n▪ To construct a neurocomputational model of imitation inspired from brain lesion, imaging and neurophysiological data.  \nA Seminal Study of Imitation and Brain Activation  \nGoldenberg’s study of imitation of meaningless gestures with a patient with callosallesion shows that the pattern of error varies with the hand used (right RH / left LH) and with the side of presentation of the visual stimulus to imitate (RVF / LVF) [1] .  \nWe present a very simple neuroanatomical model that accounts for the non uniform flow of information across the two hemispheres. The model suggests a left lateralization of the computing process and predicts amelioration in the LVF-LHand deterioration in the RVF-RH condition, which could be verified in [2] .  \nNumerous brain imaging (fMRI,PET) and lesion studies suggest the left intraparietal sulcus (parietal cortex, in green) as a neuroanatomical correlate for the left  \nlateralized process, an area that processes mainly somatic input.  \nVisuomotor Pathway  \nThe other two consistently activated brain areas in imitation of meaningless gestures are [3]:  \n▪ Extrastriate Body Area (temporo-occipital cortex, in yellow), specialized in the visual analysis of body postures and movements.  \n▪ Dorsal Premotor Area (frontal cortex, in blue) responsible for motor preparation.  \nProperties and Predictions of the Model  \nEven with high impairment rates (90%) the network converges to a good solution:  \nE is the error between the simulated position r and the desired position p of the hand  \nAs the face representation is non-uniform, some face parts are more represented (e.g. mouth) as compared to others (e.g. chin) and we observe inhomogeneities in the precision and processing times dependent on the final position.  \nFocal lesions could lead to impairment of imitation confined to some parts of the face only or to spatial errors shifted along one of the coordinate axes.  \nSevere lesions correlate with longer processing times. The time needed to do a correct imitation could be used as a measure of the severity of the lesion.  \nWe conduct kinematic and behavioral studies with apraxic patients to provide with data for validation of the model. The learning properties of our model can account for some of the brain reorganization following brain lesion.  \nThis work is done in collaboration with the Laboratory of Cognitive Neuroscience (LNCO) and Geneva University Hospital (HUG) .  \nA Neurocomputational Model of Visomotor Imitation  \nWe use Leaky Integrator Neurons to account for time. The membrane potential mi of a neuron with index i is thus governed by the first-order differential equation:  \nwhere τ is a time constant and I is the neuron input. The firing rate of a neuron is a sigmoid function of the membrane potential.  \nThe sensory input involved in imitation of meaningless gestures (i.e. visual, tactile and proprioceptive) is fully connected to the processing networks.  \nNeural activity  \nNeural activity  \nWe train the sensory weights WH, WT and WP with Kohonen’s algorithm to preserve the somatotopic organization [4] . Accordingly, we have defined the input to neuron i asa gaussian function of the distance between sensory input x and the connecting  \nweights wi:   \nWe train the weights WV and WS to learn the transformations between the sensory inputs. We use a presynaptic-gated antihebbian learning rule to associate correlated  \nneural activities:  \nwhere wi,j is the synaptic weight between a presynaptic neuron ","cbCaio7wrolXtt1o","https://ap.wps.com/l/cbCaio7wrolXtt1o","pdf",316964,1,"English","en",105,"# Motivations and Approach\n# A Seminal Study of Imitation and Brain Activation\n# Visuomotor Pathway\n# Properties and Predictions of the Model\n# A Neurocomputational Model of Visomotor Imitation\n## Neural activity\n## Simulation of the Lesion and Results\n# References","[{\"question\":\"What is the main goal of the neurocomputational model presented in the document?\",\"answer\":\"To explain the cognitive and neural mechanisms behind visuomotor imitation and learning through observation, and to construct a model inspired by lesion, imaging, and neurophysiological findings.\"},{\"question\":\"Which brain areas are highlighted as consistently activated during imitation of meaningless gestures?\",\"answer\":\"The Extrastriate Body Area for visual analysis of body postures and the Dorsal Premotor Area for motor preparation, alongside the proposed left-lateralized processing correlate in the intraparietal sulcus.\"},{\"question\":\"How does the model simulate brain lesions and what results does it produce?\",\"answer\":\"It assigns probabilistic impairment to either connection probabilities or neuron inputs, includes a decay factor for unlimited-time imitation, and fits parameters to reproduce Goldenberg’s scores while predicting effects on precision and processing time.\"}]","A Neurocomputational Model of Impaired Imitation - Research Presentation | PDF",1785731033,3,{"code":4,"msg":30,"data":31},"ok",{"site_id":23,"language":22,"slug":32,"title":13,"keywords":33,"description":14,"schema_data":34,"social_meta":84,"head_meta":86,"extra_data":88,"updated_unix":27},"a-neurocomputational-model-of-impaired-imitation-research-presentation","",{"@graph":35,"@context":83},[36,52,66],{"@type":37,"itemListElement":38},"BreadcrumbList",[39,43,47,49],{"item":40,"name":41,"@type":42,"position":20},"https://docshare.wps.com","Home","ListItem",{"item":44,"name":45,"@type":42,"position":46},"https://docshare.wps.com/document/","Document",2,{"item":48,"name":12,"@type":42,"position":28},"https://docshare.wps.com/document/research-report/",{"item":50,"name":13,"@type":42,"position":51},"https://docshare.wps.com/document/a-neurocomputational-model-of-impaired-imitation-research-presentation/120638/",4,{"url":50,"name":13,"@type":53,"author":54,"headline":13,"publisher":56,"fileFormat":59,"inLanguage":22,"description":14,"dateModified":60,"datePublished":60,"encodingFormat":59,"isAccessibleForFree":61,"interactionStatistic":62},"DigitalDocument",{"name":9,"@type":55},"Person",{"url":40,"name":57,"@type":58},"DocShare","Organization","application/pdf","2026-08-03",true,{"@type":63,"interactionType":64,"userInteractionCount":4},"InteractionCounter",{"@type":65},"ViewAction",{"@type":67,"mainEntity":68},"FAQPage",[69,75,79],{"name":70,"@type":71,"acceptedAnswer":72},"What is the main goal of the neurocomputational model presented in the document?","Question",{"text":73,"@type":74},"To explain the cognitive and neural mechanisms behind visuomotor imitation and learning through observation, and to construct a model inspired by lesion, imaging, and neurophysiological findings.","Answer",{"name":76,"@type":71,"acceptedAnswer":77},"Which brain areas are highlighted as consistently activated during imitation of meaningless gestures?",{"text":78,"@type":74},"The Extrastriate Body Area for visual analysis of body postures and the Dorsal Premotor Area for motor preparation, alongside the proposed left-lateralized processing correlate in the intraparietal sulcus.",{"name":80,"@type":71,"acceptedAnswer":81},"How does the model simulate brain lesions and what results does it produce?",{"text":82,"@type":74},"It assigns probabilistic impairment to either connection probabilities or neuron inputs, includes a decay factor for unlimited-time imitation, and fits parameters to reproduce Goldenberg’s scores while predicting effects on precision and processing time.","https://schema.org",{"og:url":50,"og:type":85,"og:title":13,"og:site_name":57,"og:description":14},"article",{"robots":87,"canonical":50},"index,follow",{"doc_id":7,"site_id":23},{"code":4,"msg":5,"data":90},[91,95,99,103,108,113,118,121,126,129,133],{"id":20,"doc_module":4,"doc_module_name":45,"category_name":92,"show_sort_weight":93,"slug":94},"Story & Novel",90,"story-novel",{"id":46,"doc_module":4,"doc_module_name":45,"category_name":96,"show_sort_weight":97,"slug":98},"Literature",80,"literature",{"id":51,"doc_module":4,"doc_module_name":45,"category_name":100,"show_sort_weight":101,"slug":102},"Exam",70,"exam",{"id":104,"doc_module":4,"doc_module_name":45,"category_name":105,"show_sort_weight":106,"slug":107},5,"Comic",60,"comic",{"id":109,"doc_module":4,"doc_module_name":45,"category_name":110,"show_sort_weight":111,"slug":112},6,"Technology",50,"technology",{"id":114,"doc_module":4,"doc_module_name":45,"category_name":115,"show_sort_weight":116,"slug":117},7,"Healthcare",40,"healthcare",{"id":11,"doc_module":4,"doc_module_name":45,"category_name":12,"show_sort_weight":119,"slug":120},30,"research-report",{"id":122,"doc_module":4,"doc_module_name":45,"category_name":123,"show_sort_weight":124,"slug":125},9,"Religion & Spirituality",20,"religion-spirituality",{"id":124,"doc_module":4,"doc_module_name":45,"category_name":127,"show_sort_weight":124,"slug":128},"World Cup","world-cup",{"id":130,"doc_module":4,"doc_module_name":45,"category_name":131,"show_sort_weight":130,"slug":132},10,"Lifestyle","lifestyle",{"id":134,"doc_module":4,"doc_module_name":45,"category_name":135,"show_sort_weight":104,"slug":136},19,"General","general"]