Dynamics of the cortical network in the visual perception and cognition

Hidehiko Komatsu

The goal of this study is to understand the dynamical aspects of neural information processing in the visual perception and cognition. In pa rticular, interaction between different cortical areas is the major focus. Many cortical areas are involved in the visual perception and cognition, and they are massively interconnected through feedforward and feedback projectio ns. Visual perception results from not only sensory inputs from the environ ment but active processes such as exploration and attention are also critica lly involved. Therefore, in order to understand the neural mechanisms of vi sual perception and cognition, it is necessary to know the neural processes in the visual cortical areas as well as those in the areas involved in the e xecution of action and attention such as the prefrontal cortex and the dynam ical interplay across these different cortical regions. We will study how s uch global neural networks spanning across different cortical areas are func tioning in the visual perception and cognition using awake preparation and c onstructing mathematical models. While the monkey is performing a visual ta sk, we will simultaneously record from different cortical areas through mult iple electrodes. We have build a multi- channel recording system which is c apable of recording simultaneously through 16 channels and an off-line spike sorting system. The recorded spike trains will be mathematically analyzed an d correlated with the visual behavior of subjects to understand what aspect of the spike trains of multiple neurons encode bottom-up and top-down signal s which can explain the variation of the behavior of the subjects. Accumula tion of such quantitative data will eventually lead to the construction of t he mathematical model of the action of the global cortical network involved in the visual perception and cognition.