roger ratcliff, marios g. philiastide, and paul sajda
DESCRIPTION
Quality of evidence for perceptual decision making is indexed by trial-to-trial variability of the EEG. DDRM 4/19/09. Roger Ratcliff, Marios G. Philiastide, and Paul Sajda. Face/car discrimination task. early. late. model. EEG. behavior. goal. - PowerPoint PPT PresentationTRANSCRIPT
Quality of evidence for perceptual decision making
is indexed by trial-to-trial variability of the EEG
Roger Ratcliff, Marios G. Philiastide, and Paul Sajda
DDRM 4/19/09
Face/car discrimination task
early late
goal
Model fit uses % correct in RT quantiles ([0.1:0.2:0.9]), so cannot be fit on a trial-to-trial basis.
=> to look at trial-to-trial relationship between model and behavior, here single-trial EEG data is used.
Is there a relationship
at the single-trial level?
modelEEG
behavior
logic
• EEG component amplitude was used to divide trials into those with high and low drift rate.
• Then the model was fit separately to the 2 groups of trials.
• The fit uses the behavioral results of the sorted trials to extract drift rate.
• Main result: the drift rate was higher on trials with higher EEG
Trials of stimulus conditionOne subject
RT, % correct RT, % correct
Fit model Fit model
Drift rate Drift rate?<
sim
ulat
ion