Cortical Circuitry Underlying Memory-Guided Sensory Decisions
As we interact with our environment, the features of objects in the visual scene are not consistently present on the retina and sensory cues used to guide visual behavior are not always available. Thus, active observers are faced with a ubiquitous task of comparing stimuli across time and space. Our research program is aimed at examining the cortical circuitry underlying successful execution of sensory comparison tasks that involve visual motion. Such tasks require processing and storage of the initial stimulus, followed by its retrieval and comparison to the current stimulus, the process that leads to the perceptual decision. The mechanisms underlying such tasks are likely to involve brain regions that process and store sensory stimuli as well as regions that control visual attention and are capable of coordinating processes involving bottom-up sensory information and top-down cognitive signals.
To examine these mechanisms, we record neuronal activity of large populations of neurons the lateral prefrontal cortex (LPFC) and in the motion processing area MT in non-human primates during memory-guided sensory comparison tasks. Our goal is to identify neural codes and network dynamics that underlie memory and comparison processes during these tasks. An important component of the work is active collaboration with computational neuroscientists and developing models aimed at mechanisms underlying maintenance and utilization of visual information in perceptual decisions.
Our studies of the way prefrontal neurons represent and utilize sensory signals and interact with neurons processing visual information during memory-guided motion comparisons have important implications for elucidating the basis of cognitive dysfunction in mental disorders associated with deficits in sensory working memory and impaired prefrontal function.