Date: Friday, May 14, 2021
Time: 12:00pm – 1:00pm
Location: Zoom Webinar – Registration Required
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Speaker: Haoran Xu, Ph.D.
Affiliation: Postdoctoral Associate, Desimone Laboratory, McGovern Institute for Brain Research at MIT

Talk title: Mapping the social brain in marmosets

Abstract: Humans can understand social scenes in one glance.  Abilities such as these are thought to rely on a network of brain regions often referred to as the social brain.  People with autism spectrum disorders typically have deficits in some aspects of social cognition, but there are disagreements over which brain regions are responsible.  We are therefore studying social cognition in the marmoset, which is a new world monkey that is highly social.  Here at MIT, several groups are preparing to study ASD in marmoset genetic models, including a model for Phelan–McDermid syndrome (shank3) created by Guoping Feng and his lab.  In the meantime, we have begun work on social cognition in wild type marmosets, with the first goal to “map” the regions of cortex important for social perception and cognition.  We showed images and videos of various types with marmoset faces and/or marmosets engaged in several forms of social behavior, together with matched control images and videos. We mapped brain regions responsive to the visual stimuli with micro electrocorticogram (ECoG) recordings over the posterior and middle temporal cortex and ventral prefrontal cortex in animals seated in a primate chair with head fixed and gaze monitored. Stimulus selectivity was evident in the “high gamma” range thought to be correlated with multiunit firing rates. Although the analyses are still in progress, we have localized some face/body/object patches, which appear to be in similar locations to areas mapped with fMRI scanning. We also identified patches that appear to be selective for social interactions. Timing data suggests a posterior to anterior sequence of activation. Moreover, we also recorded with the same ECoGs but with untethered, wireless, recordings in the same animal, during social behaviors in the home cage. With these recordings, we hope to compare patterns of activation during the perception of social stimuli with patterns activated during performance of social behaviors. With collaborations with other labs, we hope to understand how social scenes are processed and perceived in the social brain, and how the brain in ASD differs from the neurotypical brain.