Guest Speaker: Dr. Leyla Isik (Clare Boothe Luce Assistant Professor of Cognitive Science at Johns Hopkins University)

Talk Title: The neural basis of seeing social interactions

Abstract: Humans see the world in rich social detail. We effortlessly recognize not only objects and people in our environment, but also social interactions between people. This ability to perceive and understand others’ interactions is critical to function in our social world, yet the underlying neural computations remain poorly understood. In this talk, I will first review evidence from our lab and others showing that social interactions are processed selectively in the human superior temporal sulcus (STS), in regions that are largely distinct from the theory of mind network. This selectivity is observed in both controlled stimuli and even natural movies, where social interactions and mentalization are constantly co-varying. Next, I will present new research using a largescale, naturalistic video dataset and condition-rich fMRI experiment, demonstrating that social interaction information is extracted hierarchically by the visual system along the recently proposed lateral visual pathway. Finally, I will explore the computational implications of visual social interaction processing and introduce a novel graph neural network model, SocialGNN that instantiates these insights. Together, this work suggests that social interaction recognition is a core human ability that relies on specialized, structured visual representations.