CRCNS: Interhemispheric coordination for memory and action

Virtually all research on brain communication at the level of individual neurons and small populations of neurons has focused on inter-area communication within a hemisphere. While multi-area communication is undoubtedly important for understanding neurological disorders and increasingly studied, such a perspective ignores the more dramatic issue that brain processing occurs across two hemispheres. The mechanisms by which information about the world is stored, processed, and acted upon by both hemispheres are critical to much of higher brain function. Assessing the fundamental principles of interhemispheric coordination has been challenging. However, technical advances in multi-contact electrode technology and conceptual advances in dynamic attractor modeling have allowed us to make significant progress in disentangling competing hypotheses regarding how the prefrontal cortex organizes and represents memory and movements. These advances suggest that prefrontal cortex is more modular and less distributed than previously thought such that each hemisphere has a complete representation of visual space, including both left and right hemifields. The apparent redundancy provides an important avenue for work focused on neurological rehabilitation and restoration. We propose experiments that will capitalize on recent advances and our collective expertise. Our first specific aim will investigate the maintenance of spatial working memory across the hemifields in populations of neurons in prefrontal cortex. Our second specific aim will investigate how memory is transformed into a plan to move the eyes, focusing specifically on how interhemispheric spatial memory influences a single action. The final specific aim is to model spatial working memory networks across the two hemispheres, using the attractor network framework to simulate alternative architectures for brain function. Collectively, these experiments will provide new insights into the mechanisms that underlie critical brain processing circuits that are central to a host of everyday behaviors and neurological disorders.