Chapter 8 - Spatiotemporal characteristics of perceptual decision making in the human brain

Abstract

Perceptual decision-making is the process by which information gathered from sensory systems is combined and used to influence our behavior. This chapter reviews the major contributions made in the area of perceptual decision-making by monkey neurophysiology and discusses how these animal experiments have inspired scientists to study the neural correlates of perceptual decision-making in humans using noninvasive methods such as fMRI, EEG, and MEG. The findings in the chapter are primarily from the visual and somatosensory domains, which are used as supporting evidence in proposing a new theoretical model of perceptual decision-making. Findings from monkey physiology experiments parallel those from human neuroimaging experiments. Sensory evidence is represented in sensory processing areas. Accumulation of sensory evidence occurs in decision-making areas that are downstream of the sensory processing areas; these decision-making areas form a decision by comparing outputs from sensory neurons. The functional architecture for human perceptual decision-making consists of separate processes that interact in a heterarchical manner in which at least some of the processes happen in parallel. Simultaneous EEG/fMRI measurements and EEG-informed fMRI analysis techniques allow one to characterize the spatiotemporal characteristics of the network processes underlying perceptual decision-making in humans.