%0 Journal Article %A Byrne, Michael D. %A R. Anderson, John %D 2001 %T Serial modules in parallel: The psychological refractory period and perfect time-sharing %U https://kilthub.cmu.edu/articles/journal_contribution/Serial_modules_in_parallel_The_psychological_refractory_period_and_perfect_time-sharing/6618062 %R 10.1184/R1/6618062.v1 %2 http://psycnet.apa.org/doi/10.1037/0033-295X.108.4.847 %K psychology %X 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. %I Carnegie Mellon University