When others move differently: alpha-band sensory gating and conflict-monitoring networks track kinematic dissimilarity

Recent evidence suggests that kinematic similarity between observers’ motor repertoire and observed actions supports predictive mechanisms during action understanding. However, how such similarity is reflected in the neural dynamics underlying internal predictions remains unclear. Thus, we presented 21 participants with videos of reach-to-grasp actions directed toward light or heavy objects that differed in their degree of kinematic (dis)similarity respect to each observer’s motor style. We asked them to classify object’s weight while recording their electroencephalographic (EEG) signals. Spectral brain activations were localized at the source level while functional connectivity was estimated including a priori areas related to conflict and prediction error monitoring. Source analysis revealed a significant modulation of alpha-band power for highly dissimilar kinematics (false discovery rate corrected p<.05), localized in the anterior cingulate cortex (ACC), left insula (INS), and left inferior frontal gyrus (IFG). Functional connectivity in the alpha band further supported this effect showing increased density within the conflict-monitoring circuit (right and left INS, ACC) (p<.05). These findings indicate that alpha activity, which is well known for its established sensory gating function, is recruited in regions associated with conflict monitoring and prediction errors when observers were exposed to kinematics deviating from their own motor style. Therefore, whereas internal models can strongly rely on the mere observer’s motor repertoire to predict the outcome of actions with kinematics similar to their own, dissimilar movement patterns generate less precise predictions (i.e., greater prediction errors), requiring a greater reliance on incoming sensory evidence to be updated.