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)

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, Professor Marios
• Authors: Philiastides, M.G., Ratcliff, R., and Sajda, P.
• College/School: College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
• Journal Name: Journal of Neuroscience
• Publisher: The Society for Neuroscience
• ISSN: 0270-6474
• ISSN (Online): 1529-2401