EMG biofeedback for control over pre-competitive anxiety within a laboratory controlled environment.

Abstract

The purpose of this study was to investigate the effects of frontalis electromyographic (EMG) biofeedback (BF) training on sport pre-competitive anxiety variables and on motor performance, within a laboratory controlled environment with high trait anxious boys from 10 to 13 years of age. From 261 tested subjects (Ss), 80 Ss scored in the upper quartile of the Sport Competition Anxiety Test (SCAT) and from this latter sample, 20 Ss were randomly selected and randomly assigned to either a group having frontalis EKG BF (n = 10) or to a group receiving a placebo condition. The Ss were yoked for contingent positive verbal qualitative feedback (CPVQF). The Ss participated in a bogus sport competitive tournament. An elaborate bogus setting was presented to the Ss in order to control for variables such as opponents, audience and success-failure. The objective of the gate was to beat an opponent two out of three times to win a match and to achieve first place in a pyramidal tournament that consisted of five matches. The opponent was a bogus character who was purportedly in a different location and represented by a timer in the S's room. The task consisted of keeping a stability platform in-horizontal balance for as long as possible within a 30 second trial. The six laboratory sessions consisted of a practice session and five matches. Each session was comprised of an adaptation period, three games separated by three rest periods, then post measurements. During rest periods, the BF Ss (n = 10) were given frontalis EMG auditory and visual feedback while the placebo Ss (n = 10) listened to white noise. During this period, the placebo Ss were given the same instructions as the BF Ss but modified so as to describe the treatment procedures pertinent to each group. The BF group also received CPVQF from the experimenter (E) at the end of the rest period when warranted. The placebo group received the same CPVQF as their respective yoked BF S. General trait anxiety (STAIC FORM C-2) and sports specific trait anxiety (SCAT) were administered before and after the laboratory sessions. Frontalis EMG mean peak-to-peak microvoltage was recorded continuously during the 20 minutes rest periods of every session. Frontalis EMG, heart rate, and respiratory rate where recorded within every session: after adaptation, before every game (except during the practice), at the end of every rest period and at the end of every session. State-anxiety (STAIC FORM C-1) and subjective perception of optimal tension level to perform were recorded before every game. Time performance and error performance were recorded three times per session. A taped interview concluded the last session. The data for all the variables (except for trait anxiety and the post interview) was treated by a three fray ANCOVA with repeated measures using the baseline measure of the practice session as the covariate. The data for the trait anxiety variables was treated by a two way ANOVA with repeated measures. The post interview data was kept descriptive. Significant group differences were found only on the EMG variable in the general competitive setting and in the rest periods, thus, supporting the notion of specificity of frontalis EMG BF. However, the results did suggest the potential use of the frontalis EMG BF to transfer its specific effect from rest to general competitive setting. The high variability during the rest periods recorded by the placebo Ss on the EMG data also suggested the possibility that BF may have strong potential for children where the BF sodality seems valuable so as to maintain the child's attention and may also be valuable to his understanding of relaxation. The study showed significant increases in all of the anxiety parameters assessed in this study except for trait anxiety thus, providing some support for Martens' (1977) model of competitive stress. Trait anxiety was assessed differently from the former variables (pre-post design). Significant decrease in sport specific trait anxiety (SCAT) was found for both groups and could be attributed to the highly successful outcomes experienced during the tournament. The success-failure variable may have also influenced variations in state anxiety across the sessions and trials. Results on the motor performance variables as expressed by time and error showed a positive learning curve with regard to time, thus remaining in balance for longer periods of time across sessions. However, motor performance as assessed by error, increased across sessions. Results from the post interview suggest a placebo effect on subjective measures. This study does not provide support for a cross modality effect or performance enhancement under competitive stress that may be attributed to frontalis EMG BF.