Citation

Garrido MI, Dolan RJ, Sahani M. Iperception 2011; 2(2): 112-120.

Affiliation

Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3BG, England; e-mail: m.garrido@fil.ion.ucl.ac.uk.

Copyright

(Copyright © 2011, SAGE Publishing)

DOI

10.1068/i0411

PMID

23145228

PMCID

PMC3485781

Abstract

Surprising events in the environment can impair task performance. This might be due to complete distraction, leading to lapses during which performance is reduced to guessing. Alternatively, unpredictability might cause a graded withdrawal of perceptual resources from the task at hand and thereby reduce sensitivity. Here we attempt to distinguish between these two mechanisms. Listeners performed a novel auditory pitch-duration discrimination, where stimulus loudness changed occasionally and incidentally to the task. Responses were slower and less accurate in the surprising condition, where loudness changed unpredictably, than in the predictable condition, where the loudness was held constant. By explicitly modelling both lapses and changes in sensitivity, we found that unpredictable changes diminished sensitivity but did not increase the rate of lapses. These findings suggest that background environmental uncertainty can disrupt goal-directed behaviour. This graded processing strategy might be adaptive in potentially threatening contexts, and reflect a flexible system for automatic allocation of perceptual resources.


Keywords: Driver distraction;

Language: en