Biofeedback-Based Mental Training in the Military—The “Mental Gym™” Project

Thirty married couples were studied during naturalistic interactions to determine the extent to which variation in marital satisfaction could be accounted for by physiological and affective patterns between and within spouses. The authors hypothesized that (a) compared to nondistressed couples' interactions, distressed couples' interactions would show greater physiological interrelatedness or "linkage," more negative affect, and more reciprocity of negative affect and (b) these differences would be more pronounced when the interaction was high in conflict (discussing a marital problem) as opposed to low in conflict (discussing the events of the day). Heart rate, skin conductance, pulse transmission time, and somatic activity from both spouses were analyzed using bivariate time-series techniques to derive a measure of physiological linkage. Self-report affective data (obtained using a video-recall procedure) were analyzed using sequential analyses to derive a measure of affect reciprocity. The hypotheses were strongly supported; 60% of the variance in marital satisfaction was accounted for using measures of physiological linkage alone. Additional nonredundant variance was accounted for by the other physiological and affective measures.

The aim of the present study was to investigate the effect of vagal tone on performance during executive and non-executive tasks, using a working memory and a sustained attention test. Reactivity to cognitive tasks was also investigated using heart rate (HR) and heart rate variability (HRV). Fifty-three male sailors from the Royal Norwegian Navy participated in this study. Inter-beat-intervals were recorded continuously for 5 min of baseline, followed by randomized presentation of a working memory test (WMT) based on Baddeley and Hitch's research (1974) and a continuous performance test (CPT). The session ended with a 5-min recovery period. High HRV and low HRV groups were formed based on a median split of the root mean squared successive differences during baseline. The results showed that the high HRV group showed more correct responses than the low HRV group on the WMT. Furthermore, the high HRV group showed faster mean reaction time (mRT), more correct responses and less error, than the low HRV group on the CPT. Follow-up analysis revealed that this was evident only for components of the CPT where executive functions were involved. The analyses of reactivity showed a suppression of HRV and an increase in HR during presentation of cognitive tasks compared to recovery. This was evident for both groups. The present results indicated that high HRV was associated with better performance on tasks involving executive function.