Peak-to-peak measurement of P300 recorded at 0.3 Hz high pass filter settings in intraindividual diagnosis: complex vs. simple paradigms.
We compared effects of 0.3 Hz with 0.01 Hz settings of the high pass amplifier filter, and baseline-to-peak with peak-to-peak measurements of the P300 event-related potential. The key dependent variable of interest was intraindividual rate of accuracy in discrimination of oddball vs. frequent evoked P300 responses, in various paradigms. In Experiment 1 (a lab deception paradigm), we found that the combination of the 0.3 Hz filter setting and the peak-peak measurement of P300 correctly diagnosed oddball vs. frequent in 26 of 26 (100%) cases. This parameter combination outperformed all others. In a second, more field-like experiment (in that the participant knew that the experimenter was blind to ground truth), the peak-peak index again outperformed the base-peak index. It was also observed that the pre-stimulus EEG baseline variability exceeded that of the negative peak (NEG) following P300, i.e. the peak to which the peak-peak index refers P300 for computation. We also observed that the base-peak measurement of P300 is uncorrelated with NEG, and that NEG, seen only in 0.3 Hz channels, correlates highly (-0.67) with the duration of recovery of P300 to the pre-stimulus baseline EEG level as seen in the 0.01-Hz channel. However, in a final experiment using two simple visual and auditory oddball tasks, the base-peak measurement was as diagnostic as the peak-peak measurement.
Soskins
M
M
Department of Psychology, Northwestern University, Evanston, IL 60208, USA. m-soskins@northwestern.edu
Rosenfeld
J P
JP
Niendam
T
T
D000328:Adult; D004569:Electroencephalography; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation