Dynamic encoding of biological motion information in macaque medial superior temporal area

The ability to decipher biological motion information is an essential brain function that develops early in life and is evolutionarily conserved across many species. However, the neuronal encoding of biological motion information remains unclear due to the scarce electrophysiological evidence. In the current study, we tackled this issue by examining whether and how neurons in the monkey medial superior temporal cortex (MST) extract form from biological motion and encode spatial transformations in biological motion. Results revealed that MST neurons are capable of encoding form information and discriminating the horizontal and the vertical mirror transformations of biological motion. More importantly, BM information is dynamically encoded in the modulation strength of evoked spike trains rather than the average firing rate during stimulus presentation. Furthermore, the ability of MST neurons to detect various biological motion features is closely linked with the neuronal selectivity for optic flow patterns.