One of our long-standing interests is to understand the relationship between the activity of populations of cortical cells and behavioral decisions. Our working hypothesis is that the accuracy of sensory representation and intracortical communication determines the accuracy of behavioral responses.

Viral tools for gene delivery have allowed new optogenetic methods to target cells based on cell localization and connectivity. Physiological dissection of targeted circuits, primarily by depolarizing or hyperpolarizing rhodopsins, has been extremely successful in the mouse brain, but remain of limited use in non-human primate (NHP) and human brain. We have just started a series of projects to test the function of cortical circuits by manipulating their responses and then examine the impact on perceptual decision making.

It has become increasingly understood that studying the brain in a restrained laboratory rig poses severe limits on our capacity to understand the function of brain circuits. To overcome these limitations, we have constructed a wireless system that allows us to study cortical dynamics at the population level while nonhuman primates are moving freely in their natural environment. Phenomena that were difficult or impossible to observe in an experimental rig, such as foraging, sleep, or social behavior are now possible to study.