Electrophysiological (EEG) Correlates of Reward Effects on Early Sensory Perception in Humans

Abstract

Existing research suggests that reward system and sensory perception networks function in concert and that activation in one may influence the other; however, the dynamics of these influences remains poorly understood. There is general agreement regarding the existence of an interaction between bottom-up and top-down signals in perception and attentional processing. While it’s not absolutely sure what stages of perception are influenced by cognition, it has been assumed that cognitive input influences later categorization stages of visual processing, and that earlier stages are solely involved in the pure bottom up extraction of basic features of sensory signals. Several recent experiments have challenged this idea by showing that top-down modulation by cognition may extend to early visual stages of perception. Recent Electrophysiological studies have begun to probe the neural correlates of the interaction between attention/reward, perception and cognitive control in humans. . We posit that selection of the value of our choices and actions from multiple alternatives may cause suppression of the sensory representations of unselected, low value stimuli while the selected, high value stimuli are enhanced. The present project has been proposed to study the dynamics of this selective process where effects of various reward categories on attention and early sensory perception are tracked using behavioral and electrophysiological (EEG) techniques. Methods from neuroscience, signal processing, psychophysics and EEG tools will be used in the project.