Neural Mechanisms

of Selective 

Visual Attention

  The long-range goal of our laboratory is to understand the neural mechanisms of selective visual attention at the level of the individual neuron and the cortical circuit, and to relate these to perception and conscious awareness. We take as our starting point the observation that the brain is limited in the amount of visual information it can process at any moment in time. For instance, when people are asked to identify the objects in a briefly presented scene, they become less accurate as the number of objects increases. This inability to process more than a few objects at a time reflects the limited capacity of some stage (or stages) of sensory processing, decision-making, or behavioral control. Somewhere between stimulating the retina and generating a behavioral response, objects compete with one another to pass through this computational bottleneck. We seek to understand this selection process using a combination of visual psychophysics, neurophysiology, and computational neural modeling.