Hierarchal information dynamics in spatiotemporal activity pattern of inferior temporal cortex revealed by electrocorticography

Abstract

Converging evidence suggests that cortical processing is performed in a hierarchical manner. In the primate object vision, visual information is thought to be processed along the sequence of areas. We identified the direct physiological evidence for the cortical hierarchical processing as propagating activity patterns by employing electrocorticography (ECoG) in monkey, which enable us to record neural activity from wide cortical areas at high spatiotemporal resolution. Quantification of the propagating wave by symbolic local transfer entropy (SLTE) revealed both feed-forward and feedback components. We also found that SLTE topography changed during the visual stimulation. We also examined hierarchal nature of the process by comparing the ECoG activity pattern with the output from each layer of a deep neural network model. The output explained the specific spatiotemporal aspect of the ECoG activity. These results add the physiological insights of the hierarchical processing in the ventral visual stream.