Neural representation of task difficulty and decision making during perceptual categorization: a timing diagram

Philiastides, M.G. , Ratcliff, R. and Sajda, P. (2006) Neural representation of task difficulty and decision making during perceptual categorization: a timing diagram. Journal of Neuroscience, 26(35), pp. 8965-8975. (doi:10.1523/​JNEUROSCI.1655-06.2006)

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Abstract

When does the brain know that a decision is difficult to make? How does decision difficulty affect the allocation of neural resources and timing of constituent cortical processing? Here, we use single-trial analysis of electroencephalography (EEG) to identify neural correlates of decision difficulty and relate these to neural correlates of decision accuracy. Using a cued paradigm, we show that we can identify a component in the EEG that reflects the inherent task difficulty and not simply a correlation with the stimulus. We find that this decision difficulty component arises ≈220 ms after stimulus presentation, between two EEG components that are predictive of decision accuracy [an “early” (170 ms) and a “late” (≈300 ms) component]. We use these results to develop a timing diagram for perceptual decision making and relate the component activities to parameters of a diffusion model for decision making.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Philiastides, Dr Marios
Authors: Philiastides, M.G., Ratcliff, R., and Sajda, P.
College/School:College of Medical Veterinary and Life Sciences > Institute of Neuroscience and Psychology
Journal Name:Journal of Neuroscience
Publisher:The Society for Neuroscience
ISSN:0270-6474
ISSN (Online):1529-2401

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