Serial modules in parallel: the psychological refractory period and perfect time-sharing.
The authors describe ACT-R/perceptual-motor (ACT-R/PM), an integrated theory of cognition, perception, and action that consists of the ACT-R production system and a set of perceptual-motor modules. Each module (including cognition) is essentially serial, but modules run in parallel with one another. ACT-R/PM can model simple dual tasks such as the psychological refractory period (PRP), including subtle results previously explained with executive process interactive control (EPIC, D. E. Meyer & D. E. Kieras, 1997a). The central difference between the theories is that EPIC's productions can fire in parallel, whereas in ACT-R/PM, they are serial. Results from three PRP-like experiments with more demanding cognitive requirements indicate that cognitive processing for the 2 tasks need not overlap. ACT-R's activation-based retrieval processes are critical in accounting for the timing of these tasks and for explaining the dual-task performance decrement.
Byrne
M D
MD
Department of Psychology, Rice University, MS-25, 6100 Main Street, Houston, Texas 77005-1892, USA. byrne@acm.org
Anderson
J R
JR
D001288:Attention; D006801:Humans; D008960:Models, Psychological; D011597:Psychomotor Performance; D011601:Psychophysics; D011930:Reaction Time; D012033:Refractory Period, Psychological