Dynamics of oscillatory changes associated with the perception of human motion

Neurophysiological evidence suggests that a specialized cortical network is involved in the visual perception of biological motion; however, the temporal dynamics underlying this network is largely unexplored. We used magnetoencephalography to determine the spatial distribution and task-related temporal dynamics of the oscillatory activity of random and human motion. We recorded cortical responses in healthy adults while they passively viewed point-light displays of static dots, random, and human motion. By analyzing differences in the time-frequency distributions between pairs of conditions, we found that: (a) the perception of both motion conditions resulted in a significant decrease in the α/β band in the right superior occipital gyrus and a significant decrease in the β band in the right insula and (b) the human motion condition was associated with specific alterations in α, β, and γ bands with significant reductions in the α band in the right superior temporal gyrus, right precuneus, and left inferior parietal lobule, significant reductions in the β band in the bilateral superior temporal gyrus, together with a significant increase in the γ band in the left inferior parietal lobule and superior temporal regions. These data suggest that although the perception of both random and human motion involves desynchronization of oscillatory activity in α and β bands in similar cortical regions, only human motion is associated with a larger network and significant alterations in the α/β band particularly in the right hemisphere.