Cortical kinematic processing of executed and observed goal-directed hand actions

Motor information conveyed by viewing the kinematics of an agent's action helps to predict how the action will unfold. Still, how observed movement kinematics is processed in the brain remains to be clarified. Here, we used magnetoencephalography (MEG) to determine at which frequency and where in the brain, the neural activity is coupled with the kinematics of executed and observed motor actions. Whole-scalp MEG signals were recorded from 11 right-handed healthy adults while they were executing (Self) or observing (Other) similar goal-directed hand actions performed by an actor placed in front of them. Actions consisted of pinching with the right hand green foam-made pieces mixed in a heap with pieces of other colors placed on a table, and put them in a plastic pot on the right side of the heap. Subjects' and actor's forefinger movements were monitored with an accelerometer. The coherence between movement acceleration and MEG signals was computed at the sensor level. Then, cortical sources coherent with movement acceleration were identified with Dynamic Imaging of Coherent Sources. Statistically significant sensor-level coherence peaked at the movement frequency (F0) and its first harmonic (F1) in both movement conditions. Apart from visual cortices, statistically significant local maxima of coherence were observed in the right posterior superior temporal gyrus (F0), bilateral superior parietal lobule (F0 or F1) and primary sensorimotor cortex (F0 or F1) in both movement conditions. These results suggest that observing others' actions engages the viewer's brain in a similar kinematic-related manner as during own action execution. These findings bring new insights into how human brain activity covaries with essential features of observed movements of others. (C) 2015 Elsevier Inc. All rights reserved.