Dora Angelaki, PhD
Professor of Neural Science and Mechanical and Aerospace Engineering
Flexible neural coding during visually guided navigation
Natural behavior is flexible and supported by abstracted away beliefs. To understand dynamic neural processing underlying natural behaviour, we use a continuous-time foraging task in which macaques use a joystick to steer and catch flashing fireflies in a virtual environment lacking position cues. To solve the task, monkeys must dynamically update their position estimates by integrating optic flow generated by self-motion. In addition to sequential neural dynamics, patterned mixed selectivity, and strong interneuronal interactions, we found that the hidden state – monkey’s displacement from the goal – was encoded broadly in prefrontal, parietal and sensory cortex. Notably, although this task requires only mentally tracking one’s position relative to the goal, subjects physically tracked this latent task variable with their gaze; and restraining eye movements worsened task performance – an instance of embodied cognition. Task manipulations that perturbed the world model induced substantial changes in neural interactions, and modified the neural representation of the hidden state, while representations of sensory and motor variables remained stable. Critically, the more unit-to-unit couplings remap in prefrontal cortex, and the greater their stability within sensory cortex, the less αre population codes and behavior impacted by the loss of sensory evidence. Thus, flexibly switching between sensory and internal model-driven behavior may be mediated by the pattern of fine-grain lateral connectivity within prefrontal cortex.
Host Information: Hannah Payne ([email protected])
The Columbia Neuroscience Seminar series is a collaborative effort of Columbia's Zuckerman Institute, the Department of Neuroscience, the Doctoral Program in Neurobiology and Behavior and the Columbia Translational Neuroscience Initiative, and with support from the Kavli Institute for Brain Science.