The locus of dual-task interference: psychological refractory effects on movement-related brain potentials.
We sought to measure separately the motor potentials for each of 2 concurrent tasks and to use these measurements to identify the locus of dual-task interference. Lateralized readiness potentials (LRPs) were measured in the psychological refractory period paradigm, in which a separate response is required to each of 2 successive signals. As the interval between the signals decreased, the 2 reaction time (RT) tasks increasingly overlapped and the 2nd RT was prolonged. The LRP for the 2nd task was also delayed but maintained a constant temporal relation with the 2nd RT and sometimes preceded the 1st-task RT. The results indicate that (a) independent measures of the LRP can be obtained for each of 2 concurrent tasks, (b) slowing of the 2nd task was caused by a delay in processes that precede LRP onset, and (c) the 1st task may cease to interfere with the 2nd considerably before producing an overt response.
Osman
A
A
Department of Psychology, University of California at San Diego, La Jolla 92093-0109.
Moore
C M
CM
D001921:Brain / Q000502:physiology*; D003071:Cognition / Q000502:physiology; D004569:Electroencephalography; D004585:Electrooculography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D009068:Movement; D011597:Psychomotor Performance; D011930:Reaction Time