Virtually perfect time sharing in dual-task performance: Uncorking the central cognitive bottleneck

A fundamental issue foe psychological science concerns the extent to which people can simultaneously perform two perceptual-motor tasks. Some theorists have hypothesized that skilled procedural decision making and response selection for two or more tasks can proceed at the same time under adaptive executive control. The three experiments reported here support this latter hypothesis. Their results show that after relatively modest amounts of practice, at least some participants achieve perfect time sharing in the dual-task performance of basic choice reaction tasks. The results also show that observed interference between tasks can be modulated by instructions about differential task priorities and personnel preferences for darting (concurrent) or cautious (successive) scheduling tasks. Given this outcome, future research should investigate exactly when and how such sophisticated skills in dual-task performance are acquired.