Short-term mobilization of processing resources is revealed in the event-related potential.
This study investigates whether an occasional effortful improvement of performance, as asked for by a precue, is reflected in event-related potential (ERP) changes. To estimate the limits of possible effort-induced behavioral and ERP changes, we manipulated the time between precue and imperative stimulus (IS; precue interval, PCI). The subjects could, in fact, improve their performance in the effort trials, with all but the shortest PCI. The postcue ERP revealed a fronto-central contingent negative variation (CNV), which was preceded by a frontal positive/occipital negative wave (P2/N2). Both the P2/N2 and the CNV were larger for effort than for standard trials for all PCIs. For the shortest PCI (300 ms), the CNV increase was seen after the IS. The CNV increase for PCIs 600 and 300 began at about 400 ms postcue. The results suggest that effortful performance improvement is associated with prior increase of a frontocentral CNV and a preceding P2/N2. The CNV increase is thought to reflect the activity of a frontal executive process by which additional processing resources can be mobilized on a trial-to-trial basis within less than 500 ms.
Leibniz Research Center for Working Environment and Human Factors, D-44139 Dortmund, Germany. falkenstein@arb-phys.uni-dortmund.de
Michael
M
Falkenstein
Jörg
J
Hoormann
Joachim
J
Hohnsbein
Thomas
T
Kleinsorge
D000328:Adult; D002540:Cerebral Cortex / Q000502:physiology; D003265:Contingent Negative Variation; D003463:Cues; D004569:Electroencephalography; D004734:Energy Metabolism / Q000502:physiology*; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology