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Friday, February 27, 2015 - 12:00pm

IRCS Conference Room

Sabine Kastner
Department of Psychology
Princeton University

Neural Network Dynamics for Attentional Selection in the Primate Brain

Natural scenes are cluttered and contain many objects that cannot all be processed simultaneously due to capacity limitations of the visual system. Selective attention refers to a set of mechanisms that route behaviorally relevant information through large-scale cortical networks. I will discuss studies probing the visual attention network of two primates, the human and the macaque monkey, using an integrated approach of neuroimaging and invasive electrophysiology. First, I will discuss how efficient communication is set up in the large-scale attention network. While there is evidence that populations of cortical neurons synchronize their activity to preferentially transmit information about attentional priorities, it is unclear how cortical synchrony across a network is accomplished. I will discuss the unique role of thalamo-cortical interactions in influencing cortical networks to optimize their communication. Second, I will discuss the issue which neural code is used to inform behavioral outcome. We have performed comparative electrophysiology (electrocorticography in human epilepsy patients) in the primate posterior parietal cortex while subjects performed an identical spatial attention task. Our studies show that spike-phase codes predict behavioral outcome better than spike rate codes. Together, our studies provide insight into the mechanistic underpinnings of large-scale cognitive network operations.