Parieto-collicular interactions during perceptual decisions

Project Summary / Abstract Higher cognitive processing relies on the ability to reason about and act on information that is accumulated over time.

An understanding of these functions at the level of neural mechanism will inspire new approaches to treat a variety of disorders affecting sensation, thought, and action. The neurobiology of perceptual decision-making offers a window on the neural mechanisms that support these functions.

It has identified a network of brain regions in monkeys thought to be involved in accumulating sensory evidence over time and transforming this evidence into a relevant action, particularly when the action is an eye movement.

This proposal focuses on two highly interconnected areas within this network?the superior colliculus (SC) and the lateral intraparietal area (LIP)?and the ways in which they interact to support perceptual decisions.

LIP has been studied extensively in the context of perceptual decision-making and is known to represent the temporal integration of sensory evidence. Much less is known about the roles that other areas in the network play in the decision process.

In addition, a critical gap in knowledge is how LIP cooperates with and depends on these other areas to form and terminate perceptual decisions.

The aims of this proposal combine highly controlled behavior, multi-area recordings, and inactivations to clarify the role of SC in the decision process and generate insights into how SC and LIP cooperate. Aim 1 compares decision-related activity in SC and LIP directly in the same decisions.

Simultaneous multi-channel neural recordings from these two areas will reveal the signals present in SC and will allow me to determine whether they are similar to or fundamentally different from those in LIP. Aim 2 uses causal methods to investigate how decisions and signals in LIP depend on SC activity.

The experiment involves unilateral inactivation of SC and simultaneous multi-channel recordings in LIP. The results will elucidate the contribution of SC activity to the decision process. They will also constrain the neural circuits that could give rise to the decision-related signals observed in Aim 1.

Together, these aims represent an important step toward understanding how networks of brain areas support the ability to reason about and act on information.

This proposal was tailored to both exploit my extensive training in vision science and develop new skills that will be invaluable to my goal of becoming an independent scientist studying higher brain function. Dr.

Michael Shadlen, a leading expert in the neurobiology of perceptual decision-making, is the ideal sponsor for this research.

Finally, the rich scientific environment fostered by the Zuckerman Institute and the Neurobiology and Behavior graduate program at Columbia will further enhance my growth as a scientist.