Affective information processing and the assessment of anxiety

A conceptualization of anxiety as comprising three loosely coupled response systems of overt behavior, verbal report, and physiological activation has proven useful in clinical and theoretical work. With this framework as a starting point, an information-processing approach to the study of emotion is described. Emotions are conceived as affective programs within the brain, with information coded as propositions organized into associative networks. Affective expression results when such a network is accessed and processed, which can occur when a sufficient number of propositions are activated by environment stimuli and/or internal associations. It is hypothesized that information about the expressive physiology is an integral component of the associative structure, and that processing of the network accordingly results in measurable psychophysiological response. Data from studies of emotional imagery, as well as other areas of research, are reviewed in support in these theories. The utility of this approach for the assessment of anxiety disorders is discussed, and results of clinical studies are presented to suggest that individual differences in accessing and processing emotional information may bear significant implications for prognosis and treatment selection. It is speculated that differences among the anxiety disorders could be interpreted in terms of the degree of cognitive organization of the network, leading to potential refinement of current diagnostic categories. In conclusion, cognitive psychology paradigms are discussed in terms of their application to the assessment and treatment of anxiety disorders.

Strategies of arousal control: biofeedback, meditation, and motivation

A series of four experiments assessed the effects of instructions to lower heart rate on heart rate change and general arousal reduction. Various conditions of biofeedback, cognitive load, incentive, knowledge of results, and the experimenter-subject relationship were tested. Experiment 1 compared physiological responses to the delivery of direct organ feedback (i.e., heart rate) with responses to electromyographic biofeedback from the frontalis muscle area and with responses to a nonfeedback tracking task. The results suggest that neither heart rate nor muscle tension feedback is an especially powerful method for achieving sustained reductions in heart rate. Furthermore, although some specificity of physiologic pattern is apparent, biofeedback is no more effective in lowering general activation level than simple instructions to relax accompanied by a general knowledge of results. The second experiment was designed to assess the role of cognitive load in arousal reduction. Heart rate biofeedback was compared with a procedure involving minimal external information processing--the secular meditation exercise of Wallace and Benson. The results indicated a clear superiority for the meditation strategy in effecting reductions in cardiac rate and lowering activation. However, in a third experiment, meditation subjects lowered heart rate much less than observed in the previous study, and this time the reduction did not exceed that achieved by feedback subjects. Subsequent analysis suggested that the quality of the subject-experimenter relationship (active-supportive vs. formal-distant) was a significant variable in accounting for outcome differences. The above hypothesis was supported by a fourth experiment. Under conditions of high subject-experimenter involvement, the superior meditation performance of Experiment 2 was reproduced; under low-involvement conditions the Experiment 3 result of no difference between training groups was obtained. The findings suggest that the effectiveness of any method for achieving relaxation (or physiological control) rests on a complex interaction between informational and motivational imperatives of the stimulus context and definable aspects of the interpersonal exchange between subject and experimenter. This research raises serious questions about the effectiveness of the usual biofeedback paradigm as an aid to arousal reduction and the cost efficiency of its applications in the clinical situation. Furthermore, these results demonstrate the great power in relaxation experiments of psychosocial and other moderator variables, and signal the practical difficulty of their control when these variables appear to be as potent in changing physiology as the primary training methods.

Instructed heart rate control. Effects of varying feedback frequency and timing

Forty subjects participated in an experiment designed to test the effects of different feedback displays on instructed heart rate speeding and slowing. One group of subjects received information about interpulse interval length every beat. This display included specific information about when systole occurred, in addition to information about performance relative to a criterion. Two other groups received similar information about performance, but their displays were not triggered by systole; rather, information about average interpulse interval was presented either every second or every 6 seconds. A fourth group of subjects participated in a perceptual motor task in which no instructions were given to control heart rate. Results indicated that the instructed subjects generated significantly greater heart rate speeding than slowing. Groups receiving feedback produced greater changes when compared to the control group only during the speeding sessions. No differences among feedback groups were present in the slowing task. During speeding, the 1-second group's performance deteriorated dramatically in the second session. The results suggested that, in the context of a feedback task, it is information about the occurrence of systole that facilitates heart rate speeding. Real-time displays are less facilitating of heart rate change and may disrupt speeding performance when information is presented at certain "critical" frequencies. Slowing performance was again shown to be unrelated to information frequency or reinforcement rate.

Psychophysical judgment: electro-cortical and heart rate correlates of accuracy and uncertainty

The relationship between perceptual accuracy and physiological response amplitude was investigated in an auditory pitch discrimination experiment. Confidence ratings were obtained from all subjects following each trial. The stimulus set consisted of three tones of different frequencies spaced in a manner to provide both easy and difficult discriminations. Heart rate, EEG and vertical eye movement were recorded throughout the experiment. The results of the experiment indicated that the largest evoked cardiac rate response was elicited by the stimulus which produced the fewest errors in judgment; larger auditory evoked potentials, particularly the late positive component (P300), were associated with the 'easy' stimulus; greater cortical negativity was associated with the difficult stimuli. Eye activity was found to covary with judgmental accuracy; cortical slow wave activity was particularly sensitive to the confidence, or 'uncertainty' parameter. A 'decision tree' model was hypothesized to describe the processing mechanism involved in solving the discrimination problem.

Differential effects of heart rate modification training on college students, older males, and patients with ischemic heart disease

Seventy male subjects participated in a six session study of feedback-mediated heart rate modification. Three groups of subjects were compared: (1) college students, (2) patients with ischemic heart disease, and (3) healthy males, age-matched to the patients. The groups did not differ in heart rate during rest or in response to a perceptual-motor tracking task. However, the college students produced significantly larger changes in cardiac rate than the other two groups when instructed to modify heart rate (speed or slow) and provided with exteroceptive feedback. The patients showed the poorest overall feedback performance. These differences between groups were greater for speeding than for the slowing task. Relationships were explored between feedback performance and resting heart and respiration rate, drug regime, and personality questionnaires. The results were consistent with the hypothesis that interdependence between psychological stimuli and cardiovascular events is reduced in heart disease.