The Psychology and Psychobiology of Simple Decisions: Speeded Choice and Its Neural Correlates

Abstract

In this chapter, we provide a tutorial review of the class of sequential sampling models of two-choice decision-making. These models, which have been developed in cognitive and mathematical psychology over the last 50 years, provide a detailed quantitative account of performance in simple, speeded choice tasks. The models explain the major findings from a wide variety of behavioral decision tasks, including the relationship between choice probabilities and response time (RT), the speed-accuracy tradeoff, the shapes of RT distributions, and the relative speed of correct and error responses. More recently, electrophysiological recordings from decision-related brain areas in awake behaving monkeys have revealed a correspondence between patterns of neural firing and the statistical processes of evidence accumulation assumed in the psychological models. We discuss the theoretical relationship between the cognitive process of evidence accumulation and neural firing rates and show how neural data can constrain behavioral models. Importantly, constraints from neurophysiological data can be used to test between models that are otherwise difficult to distinguish. The convergence of psychological theory and neurophysiological data suggests that a common theoretical and mathematical framework is sufficient to account for simple decision-making data at neural and behavioral levels of analysis.