Effects of electrode placement on direction of T-wave amplitude changes in psychophysiological studies

Psychophysiological studies, which measure small changes in T-wave amplitude (TWA) induced by behavioral manipulations, usually employ a single electrode placement for obtaining the ECG. The present study varied electrode placement (EP) within subjects among three EPs that have been reported in the literature (a lead-II limb placement, and two chest placements) to determine whether, as has been claimed, the direction of TWA changes can be changed by varying EP. Both HR and TWA were monitored in 24 males during the Baseline, Listen, and Task phases of an iterative subtraction task. The EP variation did not affect the direction of TWA change. Reliable TWA attenuation accompanied by HR acceleration was observed in all leads.