A computational theory of executive cognitive processes and multiple-task performance: Part 2. Accounts of psychological refractory-period phenomena.

Abstract : Further simulations of multiple task performance have been conducted with computational models that are based on the Executive Process Interactive Control (EPIC) architecture for human information processing. These models account well for patterns of reaction times and psychological refractory period phenomena (delays of overt responses after short stimulus onset asynchronies) in a variety of laboratory paradigms and realistic situations. This supports the claim of the present theoretical framework that multiple task performance relies on adaptive executive control, which enables substantial amounts of temporal overlap among stimulus identification, response selection, and movement production processes for concurrent tasks. Such overlap is achieved through optimized task scheduling by flexible executive processes that satisfy prevailing instructions about task priorities and allocate limited capacity perceptual motor resources efficiently.