Title: From Sensation to Inference: Population Dynamics of Self-Motion in the Primate Cortex

For primates to navigate the world, the visual and vestibular system must interact seamlessly during movement to ensure stable perception. These two systems integrate information across numerous parts of the macaque cortex including the visual posterior sylvan region (VPS) and the intraparietal sulcus (IPS). Despite previous studies of these multi-sensory interactions in these regions, most work has focused on passive conditions, namely with a restrained animal in a moving sled experiencing externally imposed movement and
simplified visual stimuli. These paradigms do not capture the intentional actions that shape natural behavior, where self-generated movement and more complex visual scenes shape
sensory processing.

In this project, we will establish a new experimental and computational framework to examine visual-vestibular integration during active, self-generated movements. Combining the expertise of the Cullen lab and Cowan lab, we will establish a new immersive dome environment to examine this integration while the animal is trained to make an active head movement. By directly comparing active and passive conditions, we will determine how self-generated actions reshape cortical multisensory representations. In parallel, we will systematically manipulate  visual environments, by including independently moving objects and controlled mismatches between visual and vestibular signals to dissociate externalmotion from self-motion cues.

Using high-density neural recordings and population-level analyses, we will characterize how VPS and IPS encode and integrate these signals. We hypothesize that across these shifts VPS maintains a stable, context-independent estimate of self-motion, whereas the IPS flexibly
transforms these signals to support goal-directed perceptions and actions. Critically, this project moves beyond single-neuron descriptions to test how population dynamics support multisensory integration during natural behavior. These experiments will establish how the cortex integrates visual and vestibular information during active movement and provide a new, population-level computational framework for understanding how the brain distinguishes self-motion from external motion in complex
environments.