Biofeedback and relaxation effects in electromyographic biofeedback training: a methodological note.

The present study documented progressive reductions of electromyographic potentials in a biofeedback study involving instructions to 11 female and 5 male college students to both increase and decrease the feedback (and therefore the muscle tension). When only pre-experimental baselines were employed, electromyographic reductions were found with instructions to decrease the feedback. When repeated, nontreatment baseline conditions were employed as references for analysis, no electromyographic reductions were detected beyond the progressive reductions that occurred during those baselines.