1. Roger Ratcliff, Marios G. Philiastide, and Paul Sajda
DDRM 4/19/09
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

2. Face/car discrimination task

4. early
late

5. Is there a relationship at the single-trial level?
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?
model
EEG
behavior

6. 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

7. < Trials of stimulus condition One subject RT, % correct
Fit model
Fit model ?
<
Drift rate
Drift rate

8. simulation