laboratory stressor

Effects of Alpha Feedback Training on Occipital EEG, Heart Rate, and Experiential Reactivity to a Laboratory Stressor

The intent of this study was to examine whether brief alpha biofeedback training would alter the degree of physiological and experiential stress evidenced in an aversive laboratory situation. While occipital alpha and heart rate were monitored, 36 subjects underwent 8 presentations of a warning tone preceding fingertip electric shock by 30 sec. Subjects were then placed into one of three treatments taking place in dim light with eyes open. Group 1 received 24 min of contingent feedback. Group 2 received an equivalent amount of non-contingent feedback and Group 3, a no-feedback control condition, listened to music. Following the treatment period, 12 additional tone-shock pairings were presented, equally divided between eyes-open and eyes-closed trials, also with and without continuation of the treatment period “signal” (i.e. contingent, non-contingent feedback, or music). The results revealed that, in general, enhanced alpha density was maintained by the contingent feedback group during the post-treatment aversive situation. However, the reduction in alpha suppression was not systematically accompanied by corresponding heart rate and self-report reductions in situational reactivity. It was concluded that alpha feedback training was not sufficient to produce a generalized relaxation to the aversive situation. Alternative accounts of the results, focusing primarily on independence of response systems, are discussed.