A computational theory of executive cognitive processes and multiple-task performance: Part 1. Basic mechanisms

Psychol Rev. 1997 Jan;104(1):3-65. doi: 10.1037/0033-295x.104.1.3.


A new theoretical framework, executive-process interactive control (EPIC), is introduced for characterizing human performance of concurrent perceptual-motor and cognitive tasks. On the basis of EPIC, computational models may be formulated to simulate multiple-task performance under a variety of circumstances. These models account well for reaction-time data from representative situations such as the psychological refractory-period procedure. EPIC's goodness of fit supports several key conclusions: (a) At a cognitive level, people can apply distinct sets of production rules simultaneously for executing the procedures of multiple tasks; (b) people's capacity to process information at "peripheral" perceptual-motor levels is limited; (c) to cope with such limits and to satisfy task priorities, flexible scheduling strategies are used; and (d) these strategies are mediated by executive cognitive processes that coordinate concurrent tasks adaptively.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Attention*
  • Computer Simulation
  • Humans
  • Mental Processes*
  • Problem Solving
  • Psychomotor Performance*
  • Reaction Time
  • Refractory Period, Psychological