Caffeine improves anticipatory processes in task switching.
We studied the effects of moderate amounts of caffeine on task switching and task maintenance using mixed-task (AABB) blocks, in which participants alternated predictably between two tasks, and single-task (AAAA, BBBB) blocks. Switch costs refer to longer reaction times (RT) on task switch trials (e.g. AB) compared to task-repeat trials (e.g. BB); mixing costs refer to longer RTs in task-repeat trials compared to single-task trials. In a double-blind, within-subjects experiment, two caffeine doses (3 and 5mg/kg body weight) and a placebo were administered to 18 coffee drinkers. Both caffeine doses reduced switch costs compared to placebo. Event-related brain potentials revealed a negative deflection developing within the preparatory interval, which was larger for switch than for repeat trials. Caffeine increased this switch-related difference. These results suggest that coffee consumption improves task-switching performance by enhancing anticipatory processing such as task set updating, presumably through the neurochemical effects of caffeine on the dopamine system.
Department of Psychology, University of Amsterdam, Roetersstraat 15, Amsterdam, The Netherlands. Z.Tieges@uva.nl
Zoë
Z
Tieges
Jan
J
Snel
Albert
A
Kok
Jasper G
JG
Wijnen
Monicque M
MM
Lorist
K
K
Richard Ridderinkhof
D000293:Adolescent; D000328:Adult; D001288:Attention / Q000187:drug effects*; D001931:Brain Mapping; D002110:Caffeine / Q000494:pharmacology*; D002540:Cerebral Cortex / Q000187:drug effects; D002755:Choice Behavior / Q000187:drug effects*; D003118:Color Perception / Q000187:drug effects*; D003265:Contingent Negative Variation; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004569:Electroencephalography / Q000187:drug effects; D018913:Event-Related Potentials, P300 / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D009949:Orientation / Q000187:drug effects; D010364:Pattern Recognition, Visual / Q000187:drug effects*; D011930:Reaction Time / Q000187:drug effects*; D012193:Reversal Learning / Q000187:drug effects; D012660:Semantics; D012718:Set, Psychology
D002110:Caffeine