Simultaneous cognitive operations in working memory after dual-task practice.
The authors tested the hypothesis that with adequate practice, people can execute 2 cognitive operations in working memory simultaneously. In Experiment 1, 6 students practiced updating 2 items in working memory through 2 sequences of operations (1 numerical, 1 spatial). In different blocks, imperative stimuli for the 2 sequences of operations were presented either simultaneously or sequentially. Initially, most participants experienced substantial dual-task costs. After 24 sessions of practice, operation latencies for simultaneous presentation were equal to the maximum of times for the 2 operations in the sequential condition, suggesting perfect timesharing. Experiment 2 showed that a reduction of dual-task costs requires practice on the combination of the 2 updating tasks, not just practice on each individual task. Hence, the reduction of dual-task costs cannot be explained by shortening or automatization of individual operations.
Oberauer
Klaus
K
Department of Psychology, University of Potsdam, Potsdam, Germany. ko@rz.uni-potsdam.de
Kliegl
Reinhold
R
D003071:Cognition; D005500:Follow-Up Studies; D006801:Humans; D008568:Memory; D011930:Reaction Time; D013997:Time Factors