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Neural Representation of Task Difficulty and Decision Making during Perceptual Categorization: A Timing Diagram

Philiastides, Marios G.; Ratcliff, Roger; Sajda, Paul

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.

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Title
Journal of Neuroscience
DOI
https://doi.org/10.1523/JNEUROSCI.1655-06.2006

More About This Work

Academic Units
Biomedical Engineering
Publisher
Society for Neuroscience
Published Here
May 19, 2014