The Role of the Primary Visual Cortex in Processing Complex Environments

Presenter(s): Yichen Fan — Biology

Faculty Mentor(s): Denise Niell

Session: (In-Person) Poster Presentation

To survive, animals have evolved visual systems fit for extracting relevant information from complex, natural environments. In mammals, visual information flows from the eyes to the brain via two dominant gateways. First, the primary visual cortex (V1) is a higher-order structure well-studied using simple, artificial stimuli. However, its role under more complex visual conditions remains unclear. Inactivation of the cortex have surprisingly little effect on many perceptual discrimination tasks, prompting the question: what is the fundamental role of the visual cortex? Second, the superior colliculus (SC) is highly conserved across vertebrates, including mammals and lower-order animals such as fish, which lack a cortex but can still use vision for important behaviors. To ultimately elucidate the integrated role of SC and V1, we must first understand the role of V1. We hypothesized that V1 is required for object identification in complex visual scenes, but not under simple environments. We investigated this in mice using prey capture, an ethological, visually guided behavior. We optogenetically inactivated bilateral binocular V1 neurons while mice captured cricket prey in 8 environments of varying visual complexity. We found that while V1 is not necessary for prey capture in a simple visual environment, it becomes increasingly necessary as the scene becomes more complex. We will next inactivate layer 5 cortico-collicular neurons to study the integrated role of SC and cortex.