The contribution of dynamics to macaque body and face patch responses

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Primate Vision

Background:

• Previous studies identified body-selective patches in the primate visual temporal cortex using static images.
• Static stimuli may underestimate the full extent of the body representation network.
• Body dynamics convey crucial information about action and emotion.

Purpose of the Study:

• To map the complete body patch system in the macaque visual temporal cortex using fMRI.
• To investigate the role of dynamic body stimuli in activating these patches.
• To compare the response of body patches to dynamic versus static stimuli.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to scan macaque brains.
• Dynamic videos of natural-acting monkey bodies, faces, and objects were presented.
• Static images and scrambled videos served as control stimuli.

Main Results:

• Nine distinct body patches were identified in the visual temporal cortex, spanning from the superior temporal sulcus (STS) to the temporal pole.
• Body patches were consistently found in both upper and lower banks of the STS when viewing dynamic stimuli.
• Dynamic body displays elicited stronger activation in body patches compared to static images, more so than in neighboring face patches.

Conclusions:

• Dynamic body movements significantly expand the identified body-selective regions in the visual temporal cortex.
• The findings suggest that neural populations in body patches are more sensitive to motion cues than those in face patches.
• This research lays the foundation for future studies exploring the neural encoding of spatiotemporal features within these body patches.