The circuitry of the cerebral cortex underlies our ability to see . . . and hear and think and talk. Yet precisely how this is accomplished remains a deep mystery.

The Born lab studies the visual cortex of alert monkeys trained to report specific aspects of their visual experience. This allows us to define the neural correlates of specific percepts and then study their underlying mechanisms by activating or inactivating various components of circuits of interest.

Our primary approach is to record the electrical activity from hundreds of neurons simultaneously as monkeys perform visual discrimination tasks while also manipulating inputs from remote pools of neurons. One of our current interests is understanding cortico-cortical feedback, which is a ubiquitous yet poorly understood aspect of connectivity in the mammalian cerebral cortex. We have discovered that feedback is intimately involved in generating the non-classical surrounds of V1 receptive fields.  These surrounds are critical for vision, because they allow local, feature-selective responses to be modulated by the context in which they occur. This modulation is surprisingly sophisticated, and appears well suited to reduce redundancy and create sparse representations in visual cortex. More recently, we have found that feedback appears to communicate prior knowledge about a learned task that is incorporated with the incoming sensory information. This is consistent with the idea that perception is a form of statistical inference. In the future, we plan to pursue this idea aggressively using a hierarchical Bayesian model to guide our experiments.