title: Attenuation of visual reafferent signals in the parietal cortex during voluntary movement.
abstract: It is well established that the cortical processing of somatosensory and auditory signals is attenuated when they result from self-generated actions compared with external events. This phenomenon is thought to result from an efference copy of motor commands used to predict the sensory consequences of an action through a forward model. The present work examined whether attenuation also takes place for visual reafferent signals from the moving limb during voluntary reaching movements. To address this issue, EEG activity was recorded in a condition in which visual feedback of the hand was provided in real time and compared with a condition in which it was presented with a 150-ms delay, thus creating a mismatch between the predicted and actual visual consequences of the movement. Results revealed that the amplitude of the N1 component of the visual event-related potential evoked by hand visual feedback over the parietal cortex was significantly smaller when presented in real time compared with when it was delayed. These data suggest that the cortical processing of visual reafferent signals is attenuated when they are correctly predicted, likely as a result of a forward model.
authors.affiliation: Département de Kinanthropologie, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
authors.forename: Marc
authors.initials: M
authors.lastname: Benazet
authors.affiliation: Département de Kinanthropologie, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
authors.forename: François
authors.initials: F
authors.lastname: Thénault
authors.affiliation: Département de Médecine Nucléaire et de Radiobiologie, Université de Sherbrooke, Sherbrooke, Quebec, Canada; and.|Département de Radiologie Diagnostique, Université de Sherbrooke, Sherbrooke, Quebec, Canada.
authors.forename: Kevin
authors.initials: K
authors.lastname: Whittingstall
authors.affiliation: Département de Kinanthropologie, Université de Sherbrooke, Sherbrooke, Quebec, Canada; pierre-michel.bernier@usherbrooke.ca.
authors.forename: Pierre-Michel
authors.initials: PM
authors.lastname: Bernier
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D004569:Electroencephalography; D005074:Evoked Potentials, Visual; D056228:Feedback, Sensory / Q000502:physiology*; D005260:Female; D006225:Hand / Q000502:physiology; D006801:Humans; D008297:Male; D008959:Models, Neurological; D009039:Motion Perception / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology*; D009068:Movement / Q000502:physiology; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000502:physiology*; D011930:Reaction Time; D014836:Volition / Q000502:physiology; D055815:Young Adult
keywords: EEG; arm reaching movements; forward model; sensory attenuation; visual-evoked potentials