Blood pressure reactivity to active and passive behavioral conditions in hypertensives and normotensives

Blood pressure reactivity and passive behavioral tasks was studied in patients with mild essential hypertension and normotensive controls. The passive condition included 10 presentations of a 6 sec, 78 dB, 1000 Hz tone without any response requirements. In the active condition subjects were given an additional 10 tone presentations and asked to press a push-button at tone termination. The absolute and percent increase in systolic blood pressure from rest was greater in hypertensives than normotensives in response to the active condition but similar to the passive condition. It is concluded that patients with hypertension compared to normotensive controls show exaggerated blood pressure reactivity to tasks involving active but not passive coping efforts. Since the tasks used to induce active and passive coping in the present study were identical apart from coping requirements, the notion that the activity dimension in and of itself modulates reactivity differences between patients and controls is supported.     

Health behavior, knowledge and attitudes among Swedish university students

A range of health behaviors was related to beliefs concerning health practices and health knowledge. A questionnaire dealing with health-related practices, health beliefs and knowledge of health risk factors was answered by 166 male and 179 female students aged 18–30 years at Stockholm University. Female students reported engaging in better health behavior than males. Beliefs about the importance of health behaviors were closely related to their frequency of occurrence. There was only a weak relationship between health behaviors and knowledge of specific health matters. It is concluded that health attitudes rather than health knowledge determine health behavior.     

Reliability and validity of some specific fear questionnaires

Normative psychometric data on a Swedish translation of fear questionnaires concerning snakes, spiders, public speaking, and mutilation given to 223 college students are presented. High internal consistencies were found for all four questionnaires, and low intercorrelations among the four inventories emerged. In a separate study the inventories were administered to a clinical sample of spider and snake phobics. Phobics scored higher on their respective phobic scale than the college group but did not differ from controls on mutilation or public speaking scales. A significant negative correlation emerged between snake and spider scores among the phobics. One year test-retest reliabilities in the phobic sample were high. Finally, snake and spider phobics viewed and rated phobic and nonphobic slides. Snake phobics rated snake slides as more aversive than spider slides, whereas the reverse was true for spider phobics. The correlation between fear ratings and questionnaire scores was significant. Use of these scales in evaluating therapeutic changes is encouraged.     

Psychophysiological theories on sympathetic nervous system reactivity in the development of essential hypertension

Psychophysiological theories on the development of essential hypertension are reviewed and evaluated. Two interconnected theories that relate behavior to essential hypertension and account for individual differences in susceptibility to disease are the "hyperreactivity" theory and "the symptom specificity" theory. The "hyperreactivity" theory identifies individual differences in autonomic nervous system reactivity as the pathophysiological mechanism and the "symptom specificity" theory suggests that inflexible, stereotypical responding increases the risk to develop hypertension. Based on a literature review, these theories are examined. There exist both case/control and prospective studies on autonomic nervous system reactivity and the development of hypertension. It is concluded that a neurogenically mediated hyperreactivity to stress is a precursor and not an effect of hypertension. Tasks that call for active but not passive coping efforts are more efficient elicitors of reactivity differences between those at high and low risk to develop hypertension in case/control studies. In prospective studies, active tasks may also have a predictive advantage over passive with respect to blood pressure development. In the early phase of hypertension, an increased cardiovascular reactivity is accompanied by increased neuroendocrine activation. In the later phase, heightened reactivity is confined to the cardiovascular system. This does not prove but is consistent with the notion that transient episodes of increased cardiac output translate into essential hypertension by causing vascular hypertrophy. Case/control studies suggest that an increased "symptom specificity", with stereotypical responding across multiple stressors, is independent of cardiovascular reactivity and a precursor of hypertension. The literature lacks prospective studies on the clinical relevance of stereotypical responding. It is suggested that the presence of both hyperreactivity and symptom specificity in a single individual increases the risk to develop essential hypertension.     

A note on measuring human functions in systems

Abstract.— Performances in different man-machine system functions are usually not directly comparable_: It is suggested that some functions may be measured through quantities corresponding to β and d' of the signal Detection Theory. Necessary assumptions are that the task can be reduced to a binary decision and that the decision depends upon a subjective value of certainty which vanes in one dimension. The method of measurement is illustrated by an example with a hypothetical system comprising three functions: detecting, identifying and interpreting.     

Decision making, risk taking and psychological time: Review of empirical findings and psychological theory

Three domains of research (1) involvement in past and future events, (2) knowledge of the past and the future, and (3) value as a function of time (discounting) were used to elucidate man's limitations when he makes decisions based on earlier experience with consequences in the close and distant future. Evidence from all three areas illustrate that man is captured in a narrow time-space sphere around "here and now".—One consequence of this limitation is that risk-willingness increases the longer ahead the outcome of a decision is likely to occur. To specify, the less we are involved in, the less we know of and the less the consequences are evaluated the larger is our willingness to make decisions with future risks. Learning from experience seems to play a minor role in improving decision making. Ill-defined problems and non-distinct outcomes make "economic man" fairly useless as a norm for decision making in decisions with longranging effects and of a non-repititive character.—The paper ends with a discussion of strategies that can compensate for the limitations of distal cognition.     

A note on cue probability learning: what conditioning data reveal about cue contrast

In a probabilistic learning task with two complementary cues (C₁ and C₂) and two events (E₁ and E₂) the subject has a tendency to infer that E₂ will occur when C₂ occurs after he/she has observed that E₁ frequently goes with C₁. This phenomenon was termed cue contrast because it reflects the belief that C₂ contrasts with C₁ and should indicate E₂. Two kinds of predictions following from the notion of cue contrast were tested on response proportions from the first block of trials in four previously published experiments on cue probability learning. Of a total of 15 independent observations (eight within-group comparisons; seven between-group comparisons) 13 confirmed the predictions (sign test, p<0.005). It was concluded that cue utilization is both an inductive process based on association between cues and events and an inferential process based on contrast.     

Heart-rate and electrodermal orienting responses to visual stimuli differing in complexity

Orienting response (OR) theory predicts that amount of information in the stimulus, or stimulus complexity, should be an important determinant of OR elicitation and habituation, more intense and more slowly habituating ORs being expected to complex than to simple stimuli. This prediction was tested in an experiment where subjects were exposed to simple and complex visual stimuli in randomized order, while heart-rate and skin conductance were measured. Complex stimuli evoked a more pronounced deceleratory heartrate response than did simple stimuli. However, the two conditions did not differ in rate of habituation of this response. For skin conductance responses, on the other hand, the complex stimulus took more trials than the simple stimulus to reach habituation, whereas the two conditions did not differ in response magnitude. Thus, the hypothesis of more intense orienting to complex stimuli was supported by the heart-rate data, and that of slower habituation to complex stimuli, of the skin conductance data.     

Conditioned nausea after cancer chemotherapy and autonomic nervous system conditionability

There are marked individual differences in conditioned nausea after cancer chemotherapy. To examine if part of this variation is associated with individual differences in autonomic nervous system conditionability, the present study addressed whether patients with conditioned nausea acquired conditioned heart rate and electrodermal responses at a different rate than patients without conditioned nausea. Of 28 relapse-free patients who had completed cisplatinum treatment for testicular cancer between 1981 and 1986, 10 reported persistent conditioned nausea, 8 extinguished conditioned nausea and 10 no conditioned nausea. These three groups were subjected to a differential conditioning paradigm with 8 sec pictorial stimuli (circles and triangles) serving as conditioned stimuli for an unconditioned electric shock while heart rate and electrodermal activity was monitored. There were 4 habituation, 8 acquisition and 8 extinction trials with each of the two cues. Analyses of variance using nausea status as the independent variable and physiological responses as the dependent lended some support to the notion that conditioned heart rate deceleration developed in response to the reinforced compared to the nonreinforced cue during acquisition in the two groups with persistent or extinguished conditioned nausea but not in the group with no conditioned nausea. In addition, patients that displayed good, as compared to poor heart rate conditionability during acquisition, were more likely to have persistent conditioned nausea, whereas those who showed poor heart rate conditioning mostly were those without conditioned nausea. Electrodermal variables revealed no systematic differences between groups. This tentatively supports that individual differences in parasympathetic but not sympathetic nervous system conditionability may be associated with individual differences in conditioned nausea resulting from cancer chemotherapy.