Seminars
Mary Notter Lectureship
See prior Mary Notter lectures
Elizabeth Doty Lectureship
Rethinking Brain Areas: Embedded Functional Sub-Networks in the Macaque Face Patch System
David A. Leopold, PhD - Chief, Section on Cognitive Neurophysiology and Imaging (SCNI) NIMH, National Institutes of Health
The visual brain of humans and other primates is evolutionarily adapted for the perception of important stimuli. This specialization is particularly obvious in the social domain, with an abundance of brain regions nominally devoted to the analysis of faces and bodies. The so-called face patch system, for example, is a collection of cortical islands, readily identified using fMRI, in which neurons respond more vigorously to images of faces than to those of other stimulus categories. While responses of the face patch system have been studied in detail, relatively little work has been directed to understanding its operation during naturalistic modes of stimulation and behavior - namely, the visual conditions under which the primate brain evolved. In this talk, I will describe an approach in which we investigate neural responses in the face patch system during the viewing of naturalistic videos. In contrast to most visual electrophysiology studies, which ask how neural responses encode or represent stimuli, we instead analyzed single cell responses based upon their functional relationship to fMRI activity elicited elsewhere in the brain during video viewing. Using this method, we found that face-selective neurons from four nodes of the face patch system fell into approximately ten functional groups, or subnetworks, each with a distinctive brain-wide signature of coactivation. Importantly, each functional subnetwork spanned multiple face patches, and each face patch contained a mixture of nearly all subnetworks. These findings offer a new view of activity within face patches and contrast with long-standing assumptions about segregation of function that commonly shape the design and interpretation of experiments in cognitive neuroscience. The striking parallelism of distinct functional threads within in the face patch system further offers clues about how new perceptual operations might emerge, through development and evolution, within an existing domain-specialized system.
Mar 18, 2021 @ 4:00 p.m.
Zoom Link: https://urmc.zoom.us/j/97823290504