Being able to identify and analyze the form and movements of a human face and body are crucial for personal survival and social interactions. We need immediate information about identity, gender, health, emotional state, social status, and whether to approach or avoid. The lion’s share of research thus far has been devoted to facial recognition and so our understanding of how the brain perceives the bodies of others is quite small.
Past studies in body perception found that there are areas of the brain which process for specific body-regions. Seeing a body means that sensory information flows into the brain up to the thalamus which routes further up into the parietal, temporal, and occipital lobes. One area of the temporal lobe—the fusiform body area (FBA)—is known to process facial information and whole-body images (Peelen & Downing, 2005) along with the posterior superior temporal sulcus (pSTS) (Candidi et al., 2015). The occipital lobe recognizes body parts in the extrastriate body area (EBA) (Downing & Kanwisher, 2001; Carey, Knight, & Preston, 2019). These activities are related to the amygdala which assigns emotional meanigs and the insula which gives our feeling embodiment and contributes to body image.
To identify a body as that of a fellow human being, and then to further refine that visual image to label it friend or foe, takes a great deal of neural machinery. A new study using ultrahigh field 7 T fMRI technology has found a brain network that serves different aspects of body perception and that this system differentiates human bodies from those of non-humans (Li et al., 2023). The experimenters showed images of humans and monkeys to 19 test subjects while brain scanning. Their results give the first complete picture of the brain activity involved in the perception of human bodies as opposed to animal bodies.
Researchers found these brain areas involved: EBA, FBA, pSTS, inferior frontal gyrus, temporal-parietal junction, superior parietal lobe, intraparietal sulcus, inferior precentral sulcus, and dorsal frontal-parietal network. And, contributing emotional interpretations to this stream of body-form analysis is the amygdala.
Closing Thoughts
The brain processes sensory and motor information via a series of maps or body representations in the brain. Some of these are maps of our face and the faces of others, our body and various parts as well as those of others, and some maps have maps within them. Somatic experience is processed, organized, analyzed, and experienced by maps and memory. This study makes a large contribution to understanding how the brain maps the bodies of others and makes the important finding that this neural system is human-body-only which means there are even more maps to be found in the future regarding non-human bodies.
Paul Shane, Ph.D., LMT
Director, Academic Content
References
Candidi, M., Stienen, B., Aglioti, S., & de Gelder, B. (2015). Virtual lesion of right posterior superior temporal sulcus modulates conscious visual perception of fearful expressions in faces and bodies. Cortex 65, p. 184–194.
Carey, M., Knight, R., & Preston, C. (2019). Distinct neural response to visual perspective and body size in the extrastriate body area. Behavioral Brain Research 372, 112063, https://doi.org/10.1016/j.bbr.2019.112063.