Citation

Philiastides MG, Ratcliff R, Sajda P. J. Neurosci. 2006; 26(35): 8965-8975.

Affiliation

Laboratory for Intelligent Imaging and Neural Computing, Department of Biomedical Engineering, Columbia University, New York, New York 10027, USA.

Copyright

(Copyright © 2006, Society for Neuroscience)

DOI

10.1523/JNEUROSCI.1655-06.2006

PMID

16943552

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 approximately 220 ms after stimulus presentation, between two EEG components that are predictive of decision accuracy [an "early" (170 ms) and a "late" (approximately 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.

Language: en