The source of execution-related dual-task interference: motor bottleneck or response monitoring?
The present study assessed the underlying mechanism of execution-related dual-task interference in the psychological refractory period (PRP) paradigm. The motor bottleneck hypothesis attributes this interference to a processing limitation at the motor level. By contrast, the response monitoring hypothesis attributes it to a bottleneck process that not only selects the appropriate response but also monitors its execution. In two experiments, participants performed ballistic movements of different distances in Task 1 and a choice reaction time task in Task 2. In each experiment, a propagation effect of movement distance on reaction time in Task 2 indicated substantial execution-related interference. To determine the locus of this effect, we manipulated stimulus-response compatibility in Task 2. In line with the motor bottleneck hypothesis, the compatibility effect was partially absorbed during movement execution of Task 1. The results support a motor bottleneck mechanism rather than response monitoring as the source of execution-related dual-task interference.
Department of Cognitive and Biological Psychology, University of Tübingen, Tübingen, Germany. daniel.bratzke@uni-tuebingen.de
Daniel
D
Bratzke
Bettina
B
Rolke
Rolf
R
Ulrich
D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology; D002540:Cerebral Cortex / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D003657:Decision Making / Q000502:physiology; D005260:Female; D005364:Field Dependence-Independence; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D009433:Neural Inhibition / Q000502:physiology; D010470:Perceptual Masking / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D012033:Refractory Period, Psychological / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult