An experiment to test generalization of feedback from frontalis EMG.

60 subjects participated in a test of the effectiveness of frontalis EMG feedback as a generalized relaxation technique. The experiment was performed in two parts. In the first part, 30 subjects were randomly allocated to a group receiving frontalis EMG feedback (n = 10), a group receiving non-contingent feedback (n = 10) and a group instructed to relax themselves (n = 10). Each group received one baseline session and five training sessions. EMG measurements from the frontalis, trapezius and masseter muscles taken prior to and immediately after the final training session indicated that the frontalis feedback group was more effective in lowering frontalis and masseter EMG activity (though not trapezius activity) than the controls. The second part of the experiment was identical to the first with the exception that the subsidiary muscle sites were the forearm and leg extensors. The results showed that frontalis feedback was no more effective than controls in lowering the EMG levels of these muscles.