The amygdala is a key brain structure for reinforcement learning and emotion. Amygdala dysfunction is observed in a range of disorders, including depression, autism, and anxiety. I will discuss recent studies which suggest that amygdala functions extend beyond basic reward processing to sophisticated, primate-typical decision-making and social cognition. During economic choices, amygdala neurons integrate critical decision parameters, including reward probability, magnitude and risk, into subjective values. Individual amygdala neurons dynamically convert these values into representations of the monkey's forthcoming choice, suggesting an underlying decision computation. In social situations, when two monkeys observe and learn from each other's choices, amygdala 'simulation neurons' predict the choices of the partner monkey by encoding a decision computation specifically on the partner’s (but not the recorded monkey’s) trials (Grabenhorst et al., 2019, Cell). Biophysical modeling shows that simulation neurons emerge naturally from convergence between object-value neurons and self-other discriminating neurons. By encoding a decision computation during social observation, amygdala simulation neurons could allow primates to reconstruct their social partner’s mental states—a possible precursor for human Theory of Mind.
Fabian Grabenhorst obtained his DPhil from the University of Oxford, where he studied the neural basis of reward and decision-making in humans using functional MRI. His post-doctoral work with Wolfram Schultz at the University of Cambridge focused on the functions of amygdala and prefrontal neurons in economic decision processes. Fabian is a Wellcome Trust Sir Henry Dale Fellow and University Lecturer at the Department of Physiology, Development and Neuroscience, University of Cambridge. His research group combines single-neuron recordings in primates with human imaging to study the neural mechanisms for reward processing and social interactions.
Sponsored by the NYU-ECNU Institute of Brain and Cognitive Science at NYU Shanghai