Farran Briggs, Ph.D.

Critical to our comprehension of the brain is an understanding of how neuronal circuits, or the connections between neurons in the brain, underlie perception and behavior. The goals of the laboratory are to understand how neuronal circuits in the early visual system encode and process visual information and how spatial attention modulates these activities. There are two main projects that are currently underway in the laboratory. The first aims at understanding the mechanism by which visual attention modulates the activity of neurons and circuits in the early visual pathways. We have recently shown that attentional modulation of neurons in the primary visual cortex depends critically on the match between the feature selectivity of individual neurons and the features required for successful task completion. We continue to explore the mechanisms of attention at the granular and circuit level in order to develop a more comprehensive understanding of visual attention. The second project in the lab is designed to elucidate the functional role of the corticogeniculate feedback circuit in visual perception. We have shown that corticogeniculate neurons connecting primary visual cortex with the visual thalamus in the feedback direction are morphologically and physiologically diverse. Recently, we utilized an innovative combination of virus-mediated gene delivery and optogenetic techniques to show that corticogeniculate feedback controls the timing and precision of thalamic responses to incoming visual information. Ongoing experiments will further define how corticogeniculate feedback regulates the flow of information about distinct visual features in the environment.