Control of cardiac response under aversive stimulation. Superiority of a heart-rate feedback condition

The effects of nonconcurrent and concurrent relaxation training on cardiovascular reactivity to a psychological stressor

Eight patients in a cardiac rehabilitation program, after exposure to two psychological stressors approximately equivalent with respect to cardiovascular reactivity, were given nonconcurrent progressive muscle relaxation training and retested for reactivity. They were then provided with relaxation training concurrently with one of the stressors and exposed again to the two stressors. No significant effects for nonconcurrent progressive muscle relaxation training were detected. Concurrent training, in contrast, produced reductions in both systolic and diastolic blood pressure. Reductions resulting from training on the target stressor showed little tendency to generalize to the nontarget stressor; the discrimination was particularly well defined for systolic blood pressure. We conclude that muscle relaxation techniques are maximally effective in reducing reactivity to psychological stressors when relaxation training is provided concurrently with the stressor. Our findings further suggest that to inculcate the relaxation response reliably across different situations, specific training to enhance generalization may be needed.

Reducing heart rate reactivity to stress with feedback. Generalization across task and time

Heart rate (HR) reactions to two behavioral stressors (videogame and mental arithmetic) were measured in 8 experimental subjects who received biofeedback training and 8 matched control subjects during three assessment periods: pretraining, posttraining, and one-week follow-up. Experimental subjects exhibited significant reductions in HR following a training session in which they received ongoing HR feedback while playing a videogame. Control subjects, who played the same number of videogames without HR feedback, showed smaller HR reductions. During the training session, all subjects were instructed to reduce HR while maximizing game performance. In comparison to controls, experimental subjects (a) maintained lower HRs during videogame presentations after a one-week period and (b) generalized these HR reductions to the mental arithmetic challenge at follow-up. Performance on the videogame declined from posttraining to follow-up for experimental subjects but not for control subjects. No group difference in mental arithmetic performance was observed.

The effect of feedback-assisted reduction in heart rate reactivity on videogame performance

In 67 male volunteers, we examined the reduction of cardiovascular responsivity to a psychomotor challenge (videogame) achieved by use of heart rate (HR) feedback and effects of these procedures on concomitant behavioral performance. Each subject participated in a pretraining assessment of his cardiovascular responses to the videogame, a training condition, and a posttraining assessment identical to the initial evaluation. During training, subjects were assigned to one of four conditions: (a) a habituation control group receiving no instructions to alter HR (HC); (b) an instructions-only control group receiving instructions to maintain a low or unchanged HR during videogame presentations (IC); (c) a feedback group receiving instructions to reduce HR using ongoing HR feedback (FB-); or (d) a feedback group receiving instructions to lower HR and given HR feedback plus a score contingency in which total game score was jointly determined by subjects' game performance and success at HR control (FB+). Subjects receiving feedback (FB+, FB-) exhibited greater reductions in HR response to the videogame in the posttraining assessment than control (HC, IC) subjects; FB+ subjects showed greater HR reductions than subjects in any other group. FB+ and FB- subjects showed a lower SBP at posttraining relative to the two control groups, but no reduction in task-induced blood pressure reactivity. There were no group differences in videogame performance, either before or following training.

Self-instructed relaxation: a therapeutic alternative

A self-instructed relaxation program was compared with therapist-instructed relaxation and waiting list controls. Self-report anxiety measures ( IPAT and STAI ) and a psychophysiological stress profile (frontal EMG, GSR, heart rate, finger temperature monitored under relaxation and stressor conditions) were utilized pre- and posttreatment to determine efficacy. Self-monitored heart rate, respiration rate, and finger temperature were used to monitor home practice sessions. Subjects reported increased ability to relax and control stress; however, frontal EMG measured under stressor conditions was the only dependent measure to confirm this perception. No between-group differences on any other dependent measures were observed. Reliable changes on all self-monitored home practice measures were observed, suggesting that this procedure is a useful gauge of home practice.

Instructed heart rate control in the presence and absence of a distracting task: the effects of biofeedback training

Twenty volunteers participated in a single-session experiment in which bi-directional heart rate (HR) control was assessed before and after brief unidirectional HR biofeedback. Subjects attempted to raise (INC) and lower (DEC) HR while performing mental arithmetic, as well as in no-task conditions. Biofeedback training was also carried out in the presence and absence of mental arithmetic. Subjects were divided into two groups on the basis of initial HR reactivity to mental arithmetic. Group U received feedback and instructions to raise HR during the training period, while group D attempted to lower HR. Significant differences in HR modifications during INC and DEC trials were observed prior to any biofeedback training in no-task conditions. Following training, however, ability to raise HR deteriorated in group D, while HR decelerations were impaired in group U. Unidirectional training in HR control thus handicapped subsequent attempts to modify HR in the reverse direction. The pattern of HR change was generally paralleled by respiration rate. Subjects were also able to influence the cardiac reactions to mental arithmetic even before the administration of biofeedback. The data nevertheless suggest that training affects the magnitude of HR reactions after the biofeedback is withdrawn. In the biofeedback phase itself, the HR increases and decreases produced by groups U and D, respectively, were diminished on simultaneous mental arithmetic performance.

Voluntary control of cardiovascular reactions to demanding tasks

Three groups of 10 normotensives participated in a study exploring voluntary control of cardiovascular reactions to cognitive tasks. Pulse transit time (TT), interbeat interval (IBI), skin conductance level, and respiratory variables were monitored throughout one introductory and four experimental sessions. The groups were matched on the basis of initial TT and IBI responses to the taxing arithmetic and reasoning tasks. During experimental sessions, one group (FB) was provided with visual analogue TT feedback, while the REL group was given detailed relaxation instructions. A third group (CON) performed the same sequence of tasks but was not instructed to modify cardiovascular reactions at any point. Training in voluntary control was carried out in resting (no-task) conditions, and during task administration. Both treatment groups showed lower cardiovascular reactions than controls in task trials. Only REL subjects lengthened TT in no-task conditions, while both FB and REL groups showed smaller cardiovascular reactions than CON during the tasks. Effects were confined to cardiovascular variables, since respiratory and electrodermal reactions during task administration were similar in all groups. The effects of treatments were especially marked among the most reactive subjects.

Voluntary heart rate deceleration: a critical evaluation

This experiment was designed as a test of the view that the human heart rate (HR) deceleration response can be brought under voluntary control, when some form of exteroceptive feedback is available. Sixteen female volunteers were randomly assigned to two groups. The first group received instructions to decrease their HR plus a continuous negative (failure) binary feedback, while the second group received only the instructions. Each subject was given four sessions of HR deceleration training. Two identical tests were presented, one before and the other after the series of training sessions. These tests were divided into two parts. In the first part, subjects attempted to decrease their HR while undergoing an ischemic arm pain stress. In the second part, subjects performed a 40-trial HR discrimination task. The results indicate that all subjects decrease HR during both rest and voluntary control periods within each training session, but there are no significant group differences, no improvement in HR deceleration control over the four training sessions, and no difference in performance between rest and voluntary control periods. Similarly HR, blood pressure (BP), and the HR x BP product levels during the ischemic stress condition and the HR discrimination performance do not show group differences. It is suggested that the HR deceleration response may not meet the criteria generally applied to the definition of a voluntary response.

The role of behavioral conditioning in the cardiovascular adjustment to exercise

The purpose of this study was to determine if normal subjects could be trained to attenuate their cardiovascular responses while exercising on a bicycle ergometer. Ten young, untrained subjects exercised on a bicycle ergometer for five sessions. Half of the group was asked to slow their heart rate while exercising with heart rate feedback during exercise. Their average heart rate increase was 20% less than that of the control subjects, who exercised without feedback. The control subjects subsequently also received feedback during exercise and they were able to attenuate their heart rate responses comparably. Systolic blood pressure was not affected by feedback training. Changes in rate-pressure product paralleled changes in heart rate. These data show that autonomically mediated adjustments to exercise can be brought under experimental control through the use of appropriate behavioral techniques.

Behavioral medicine approaches to hypertension: an integrative analysis of theory and research

This article compares behavioral and biological approaches to hypertension, highlights some of the practical, semantic, and theoretical issues involved, and attempts a constructive, behavioral medicine integration of these approaches. The major behavioral approaches to hypertension are described, with a focus on their conceptual limitations as stimulants to research into psychobiological mechanisms. A biobehavioral systems analysis of hypertension is outlined, emphasizing the role of the central nervous system as a common pathway relating environmental and behavioral factors to cardiovascular regulatory dynamics and disease. Schwartz's concept of blood pressure disregulation is discussed, by which behavioral "feedback loops" may be included in the pathogenesis of homeostatic disorders. A detailed discussion of concepts underlying the clinical pharmacological approach to hypertension is provided; parallels are drawn between the conceptual framework and the theoretical and practical questions facing behavioral researchers concerned with hypertension. Synergistic interactive effects of drug and behavioral treatments are proposed. A biobehavioral overview, which links pressor and depressor stimulus patterns to both pathogenesis and therapy, can serve to integrate the previous biobehavioral systems analysis, the conceptual framework of clinical pharmacology, and the notion of biobehavioral disregulation of blood pressure. Implications for future behavioral medicine research in hypertension are provided.