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Original Research ARTICLE

An information theoretical approach to task-switching: evidence from cognitive brain potentials in humans

Francisco Barceló^1,2,*, José A. Periáñez^1,2 and Erika Nyhus³

Department of Psychology, Universitat de les Illes Balears, Palma de Mallorca, Spain

Institut Universitari d’Investigació en Ciències de la Salut, Palma de Mallorca, Spain

Department of Psychology, University of Colorado, Boulder, CO, USA

This study aimed to clarify the neural substrates of behavioral switch and restart costs in intermittently instructed task-switching paradigms. Event-related potentials (ERPs) were recorded while participants were intermittently cued to switch or repeat their categorization rule (Switch task), or else they performed two perceptually identical control conditions (NoGo and Oddball). The three tasks involved different task-sets with distinct stimulus-response associations in each, but identical visual stimulation, consisting of frequent colored shapes (p = 0.9) and randomly interspersed infrequent black shapes (p = 0.1; quotidn+quotidn and quotidn×quotidn symbols). Behavioral restart costs were observed in the first target responses following all black shapes in the Switch and NoGo tasks – but not in the Oddball task – and corresponded with enhanced fronto-centrally distributed early cue-locked P3 activity (peak latency 325–375 ms post-cue onset at the vertex). In turn, behavioral switch costs were associated with larger late cue-locked P3 amplitudes in the Switch task only (peak latency 400–450 ms post-cue onset at mid-parietal sites). Together with our information theoretical estimations, ERP results suggested that restart and switch costs indexed two neural mechanisms related to the preparatory resolution of uncertainty: (1) the intermittent re-activation of task-set information, and (2) the updating of stimulus-response mappings within an active task set, as indexed by early and late cue-locked P3 activations, respectively. In contrast, target-locked P3 activations reflected a functionally distinct mechanism related to the implementation of task-set information. We conclude that task-switching costs consist of both switch-specific and switch-unspecific processes during the preparation and execution stages of task performance.

Keywords:

cognitive control, information theory, novelty, set shifting, response uncertainty, working memory

Citation:

Barceló F, Periáñez JA and Nyhus E (2008). An information theoretical approach to task-switching: evidence from cognitive brain potentials in humans. Front. Hum. Neurosci. 1:13. doi: 10.3389/neuro.09/013.2007

Received:

15 October 2007;

Paper pending published:

29 November 2007;

Accepted:

03 January 2008;

Published online:

28 March 2008.

Edited by:

Robert T. Knight, University of California Berkeley, USA

Reviewed by:

Kenneth Hugdahl, University of Bergen, Norway
Kimmo A. Alho, University of Helsinki, Finland

© 2008 Barceló, Periáñez and Nyhus. This is an open-access article subject to an exclusive license agreement between the authors and the Frontiers Research Foundation, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.

*Correspondence:

Francisco Barceló, Department of Psychology, Universitat de les Illes Balears; Institut Universitari dquotidnInvestigació en Ciéncies de la Salut (IUNICS), Ctra. Valldemossa km 7.5, 07122 Palma de Mallorca, Spain. e-mail: f.barcelo@uib.es