Is dual-task slowing instruction dependent?
When 2 tasks must be performed concurrently, each requiring a choice of response, dual-task slowing is typically found. However, E. H. Schumacher et al. (1997) reported that dual-task slowing can be eliminated when equal priority is assigned to each task. Experiment 1 largely confirmed this with the same tasks as Schumacher et al. (tasks using stimulus-response combinations of visual-manual and auditory-vocal pairings). Experiment 2 retained the equal-priority instructions but switched the task pairings (to visual-vocal and auditory-manual); substantial dual-task slowing occurred. Experiment 3 used the same two response sets but only a single stimulus; slowing was again obtained despite equal priority instructions. Equalizing task priority was not sufficient to eliminate interference; relatively unusual cases in which dual-task interference is eliminated seem to depend on task-specific features.
Levy
J
J
Department of Psychology, University of California, San Diego 92093, USA. jlevy@tx.technion.ac.il
Pashler
H
H
D002755:Choice Behavior; D006801:Humans; D007858:Learning; D011930:Reaction Time