Instrumental conditioning of diastolic blood pressure in essential hypertensive patients

Eighteen male essential hypertensive patients participated in an experiment designed to compare two strategies for controlling high blood pressure. Each strategy was derived from the instrumental learning literature, and the aim was to treat the blood pressure response as an operant and determine the most effective conditioning procedure for manipulating it. The results demonstrate that patients could be conditioned to lower blood pressure by 20% to 30% over a period as brief as four days by providing an external signal and verbal praise contingent upon each reduction in diastolic pressure that met a pre-set criterion.     

Independence of blood pressure and locomotor hyperactivity in normotensive and genetically hypertensive rat

The spontaneously hypertensive rat (SHR) exhibits locomotor hyperactivity in comparison to its normotensive progenitor Wistar-Kyoto (WKY) strain. We asked whether the hyperactive behavior was a direct consequence of elevated blood pressure in the hypertensive rat. Three experimental protocols were used to chronically alter blood pressure. In the first protocol, a group of adult SHRs was given hydralazine (20 mg/kg/day) in their drinking water to lower blood pressure. These animals exhibited a significant decrease in blood pressure, but no change in locomotor activity. In the second protocol, young SHRs (4 weeks of age) were treated with the same dosage of hydralazine until 16 weeks of age. Blood pressure was significantly decreased in these animals with no change in locomotor activity. In the third protocol, normotensive WKY and Sprague-Dawley (SD) rats were made hypertensive with unilateral renal clips. The resulting increase in blood pressure in these animals did not alter locomotor activity. These results suggest that locomotor hyperactivity is an inherent property of the SHR and is independent of blood pressure.     

The behavioral control of high blood pressure

Stress management and relaxation training lower the blood pressure of many mild hypertensives substantially through mechanisms that are as yet unclear but may include behavioral and cognitive change. It is almost certain that the reduction of weight in the obese, drinking in heavy drinkers, and increased exercise in the sedentary also reduces pressure usefully in hypertensives, and opportunites exist for the application of behavioral principles to improve the effectiveness of programs to alter these behavioral risk factors. It is fortunate that behavioral methods for the control of hypertension exist and are making progress since there are increasing doubts about the effectiveness of pharmacological solutions for mild hypertension. Notice to Readers: This is the second in a three-part series on Health Psychology. Part I appeared in the Spring ’87 issue (vol. 6, no. 1); copies may be purchased ($15 individuals, $20 institutions) by sending a check, moneyorder, or charge card number (MasterCard, Visa, American Express; include expiration date and signature) to: Current Psychological Research & Reviews, Transaction Periodicals Consortium, Dept. 4010, Rutgers University, New Brunswick, NJ 08903. The author was supported by the Medical Research Council during the writing of this paper.     

Adult blood pressure reduction in spontaneously hypertensive rats reared by normotensive Sprague-Dawley mothers.

Spontaneously hypertensive (SHR), Wistar-Kyoto (WKY) normotensive, and Sprague-Dawley (SD) normotensive rats were either reared by their natural mothers (controls) or fostered to a mother of one of the other strains. The effects of rearing environment were assessed by measures of body weight at weaning and adult resting mean arterial blood pressure (MAP) and heart rate (HR). At weaning, SHR control rats weighed less than WKY controls which in turn weighed less than SD controls. SHR and WKY rats reared by SD mothers weighed significantly more than their respective controls, whereas SD rats reared by either SHR or WKY mothers weighed less than SD control rats. Manipulation of the maternal environment was attended by a change in adult resting MAP in only one group. SHR rats reared by SD mothers had MAPs which were significantly lower than SHRs reared by their natural mothers. No within-strain adult HR differences were observed between control and cross-fostered groups. These data indicate that the effects of cross-fostering on adult resting MAP previously reported for SHR and WKY animals are generalizable to another normotensive strain. That is, genetically hypertensive (SHR) animals exposed to a normotensive (WKY or SD) maternal environment display a reduction in adult resting MAP, whereas hypertension or an increase in adult MAP is not induced in normotensive rats (WKY or SD) as a consequence of exposure to a hypertensive maternal environment.     

Patient and health care provider views of depressive symptoms and diabetes in American Samoa

High Type 2 diabetes prevalence, associated with recent cultural changes in diet and physical activity, characterizes the U.S. territory of American Samoa. Comorbid diabetes and depression rates are high worldwide and contribute to negative diabetes outcomes; these rates have not been assessed in American Samoa. In this study, 6 focus groups were conducted with 39 American Samoan adults with diabetes; questions on perceptions of diabetes and depressive symptoms were included. Thirteen health care staff interviews were conducted to gain insight into diabetes care in American Samoa. Focus groups and health care staff interviews were translated, transcribed, and entered into NVivo 8 to facilitate analysis. Thematic analysis showed that diabetes patients saw depressive symptoms as directly contributing to high blood sugar. However, these symptoms were rarely mentioned spontaneously, and providers reported they seldom assess them in patients. Many patients and health care staff believed the best ways to respond to feelings of depression involved relaxing, leaving difficult situations, or eating. Staff also discussed cultural stigma associated with depression and the importance of establishing rapport before discussing it. Health care providers in American Samoa need training to increase their awareness of depressive symptoms' negative impact on diabetes management in patients who screen positive for depression. All providers must approach the subject in a supportive context after establishing rapport. This information will be used for cultural translation of a community health worker and primary care-coordinated intervention for adults with diabetes in American Samoa, with the goal of creating an effective and sustainable intervention.     

Interrogative pressure in simulated forensic interviews: The effects of negative feedback

Much experimental research on interrogative pressure has concentrated on the effects of leading questions, and the role of feedback in influencing responses in the absence of leading questions has been neglected by comparison. This study assessed the effect of negative feedback and the presence of a second interviewer on interviewee responding in simulated forensic interviews. Participants viewed a videotape of a crime, answered questions about the clip and were requestioned after receiving feedback. Compared with neutral feedback, negative feedback resulted in more response changes, higher reported state anxiety and higher ratings of interview difficulty. These results are consistent with Gudjonsson and Clark's (1986) model of interrogative suggestibility. The presence and involvement of a second interviewer did not significantly affect interviewee responding, although trait anxiety scores were elevated when a second interviewer was present. The theoretical and applied implications of these findings are considered.     

Self-monitoring and blood pressure

The association between self-monitoring (regulation and control of nonverbal and expressive behavior) and blood pressure was examined in a field study of 594 municipal employees. For persons not taking antihypertensive medication, the Acting/Extraversion scale was mildly positively associated with resting blood pressure among whites in general, blue collar, clerical, and professional groups. Stronger positive correlations were obtained for attorneys and customer service representatives. These results are contrasted with slightly negative associations for blacks in general, first-level supervisors, and a group of previously studied union stewards. An interactive effect was also obtained between Acting/Extraversion and relative participation in work versus nonwork groups and activities; Acting/Extraversion and systolic pressure were inversely related for employees more active in extrawork groups but not related among other workers. Differential consequences of greater or lesser interpersonal involvement and emotional regulation in different jobs are considered.     

Tonic and phasic stimulus control of blood pressure responses using opposing unconditional stimuli

The transswitching paradigm was used in the present study to investigate the effects of tonic (long duration) environmental stimuli paired with opposing unconditional stimuli on human blood pressure. Sixty volunteers participated for two sessions, one week apart. Subjects were presented with a pseudorandom sequence of four trials of red lights (five minutes each) and four trials of blue lights (five minutes each) within each session. All subjects received the cold pressor test during the red lights. During the blue lights, half the subjects received warm water and the other half received a neutral temperature water. Subjects received the presentations of the water in one of three methods: as determined by the experimenter, preceded by a warning signal, or self-administered. The results indicated that conditional and unconditional responses during the red lights were progressive increases in blood pressure. During the blue lights associated with warm water, conditional and unconditional responses were often progressive decreases in blood pressure. The method of administration of the water affected the magnitude of the unconditional responses. Evidence for phasic stimulus control was not as unequivocal as tonic stimulus control. The present results indicated that it is possible to modify blood pressure in two directions (increases and decreases) when two high contrast, opposing unconditional stimuli are presented.     

Effects of a high salt diet on blood pressure responses to acoustic stimuli in borderline hypertensive rats (BHR)

The borderline hypertensive rat (BHR) responds to environmental and dietary stressors with elevated blood pressure. The first two months of a high salt diet appear to be the time of greatest sensitivity to salt effects on the blood pressure of BHR. The current study was conducted to examine whether exposure to salt diets varying in duration for up to two months differentially affects baseline blood pressures (systolic, SBP, and diastolic, DBP) and blood pressure responses to novel acoustic stimuli in BHR and normotensive Wistar-Kyoto (WKY) rats. Male BHR and WKY were fed a control (1%) salt diet or a high (8%) salt diet for 1, 1.5, 2.5, or 8.5 weeks. SBP and DBP responses to an acoustic stimulus (85 dB, 3 kHz) were measured upon completion of the diets at 12 weeks of age. Ten acoustic trials (one stimulus/minute) were presented and blood pressure responses were recorded in 2-second blocks spanning the 10 seconds prior to and following stimulus presentation. BHR had higher resting SBP and DBP than WKY, and 8.5 weeks of 8 percent salt increased SBP markedly in BHR. SBP and DBP labilities in the initial trial were greater in BHR than WKY with high salt diet durations of 2.5 and 8.5 weeks producing greater lability in later trials. Few differences were noted in pressor responses, but BHR had more dramatic depressor responses than WKY in early trials, and BHR pressures had a more dramatic return to baseline. It appears that genetic history and salt diet can affect blood pressure lability and recovery in response to novel stimuli in genetically susceptible animals.     

Hostile affect and casual blood pressure

Abstract

The present study investigated the relation between hostile affect and casual blood pressure in men and women. Data were collected from two independent samples: (1) 204 university students, and (2) 175 adults from the community. Findings on blood pressure-hostile affect linkage are reported with age and body-mass index corrected values. Data were analyzed for subgroups split at the median for hostility and also for tercile subgroups. Median splits revealed no relationship between hostility and blood pressure. Systolic blood pressure tended to be highest in the medium and high hostility terciles. The diastolic pressure-hostility link in men represented a “V”-shaped curve. In women, there was no relationship. Heart rate levels were consistently unrelated to hostile affect. The importance of testing for linear as well as curvilinear relationships in future studies is highlighted.     

Coping strategies and diastolic blood pressure

An organizational field study involving 95 civil service employees examined the ways these individuals coped with the stressful events of their daily living. Lazarus' cognitive-phenomenological analysis of psychological stress provided the theoretical framework. Subjects indicated on Lazarus' Ways of Coping Checklist those coping thoughts and actions used in the specific encounter described as stressful. As hypothesized, individuals experiencing higher diastolic blood pressure were more likely to cope using strategies characterized by wishful thinking, avoidance, and minimization of threat than were individuals exhibiting lower blood pressure. Implications from both an individual and organizational perspective are discussed.     

Operant control of response latency in monkeys: evidence for a central explanation

Two monkeys (M. mulatta) were trained to press a telegraph key after onset of a tone and release it quickly in response to a subsequent light or click stimulus occurring after a variable interval. After training first with a fixed time limit on response latency for key release and then with a continuously adjusting limit, reaction time to click was 160 msec and to light, about 200 msec. Temporal contingencies or "payoff bands" were then introduced which reinforced only responses with latencies which fell between two limits 50 msec apart. Feedback was given as to whether each latency was too slow, within the band, or too fast. A trained monkey could precisely center its latency distribution on any 50 msec-wide payoff band located from 200 to 600 msec after the stimulus, with from 60 to 80% of its responses achieving reinforcement. Distribution statistics were comparable to those of trained human subjects. Because such precise timing might be accomplished by a peripheral adjustment, such as changing the manner of holding the key, latency of electromyographic activation was measured in participating arm muscles in one monkey. Electromyographic activation preceded key release by a constant interval, regardless of response latency, indicating a more central mechanism for timing of brief intervals.     

The depth of history and explanation as benefit and bane for psychological control theories

A longstanding debate has recently re-erupted in the self-regulation literature around the concept of self-efficacy. This article presents an argument that the debate emerges from a lack of understanding of the history of control theories within both the social and physical sciences and the various levels of explanation to which phenomena can be subjected. This history, coupled with the issues of determinism, materialism, and empiricism evoked by the deeper level of explanation that some versions of control theory provide, has led some critics to mis-apply non-psychological properties to control theories and obscure their usefulness. Here, the usefulness of a deeper control theory level of explanation is illustrated using comparisons with explanations found in goal-setting theory and social cognitive theory.     

Age-related differences in ambulatory blood pressure during daily stress: evidence for greater blood pressure reactivity with age

Prior research on age and emotions has found that older adults may show better physiological regulation to stressful stimuli than do younger adults. However, the stress reactivity literature has shown that age is associated with higher cardiovascular reactivity to laboratory stress (J. R. Jennings et al., 1997). The authors investigated these conflicting findings further by examining daily ambulatory blood pressure in 428 middle-aged to older adults. Consistent with the age and reactivity literature, relatively old individuals showed significantly greater increases in ambulatory diastolic blood pressure compared with younger individuals when dealing with daily stressors. However, results also revealed that relatively old individuals reported less of an increase in negative affect during daily stress compared with their younger counterparts. The results of this study are consistent with the age-related increase in cardiovascular risk but highlight the complex links between stress and different facets of the aging process.     

Social influence in investigative interviews: The effects of authority on informational elements produced in interviews and written statements

This study examined the effect of a principle of social influence—authority—on the informational elements in an investigative interview. Community participants told the truth or lied about a mock crime in a high or low authority context. Informational elements were coded from their oral responses in the interviews and written responses in a statement prior to the interviews. Rapport was rated by the interviewers and participants. The authority condition produced effects on the informational elements in both the interviews and written statements but mainly for truth tellers. Rapport also had direct effects on the informational elements but authority did not affect rapport and rapport did not mediate the effect of authority on the informational elements. These findings had theoretical, empirical, and practical implications.     

Behavioral predictors of blood pressure variation in hypertensives and normotensives

This study examined the relative impact of five behavioral factors--activity, posture, location, social involvement, and tension--on the 24-hr blood pressure (BP) variability of 21 normotensives, 18 borderline hypertensives, and 18 sustained essential hypertensives. Multiple-regression analyses indicated that within each diagnostic group, activity accounted for more variance in BP variability than any other behavioral dimension. For each behavioral dimension examined, the magnitude of the relationship with BP was generally greater for the normotensives than for both hypertensive groups. In contrast, variation due to individuals was a better predictor of BP variability for the two hypertensive groups than for the normotensive group. Number of months hypertensive and use of antihypertensive medication were related to BP variability for the sustained hypertensive group. Findings have implications for the use of ambulatory BP monitors and interpretation of resulting data.     

Feasibility and effectiveness of school-based relaxation in lowering blood pressure

Progressive muscle relaxation (PMR) is a broadly useful anxiety reduction technique that has been found to lower blood pressure (BP) in essential hypertension. The present investigation is the first to evaluate the feasibility and efficacy of wide-scale PMR instruction as a public health promotion strategy aimed at adolescents. Students (N = 1,400) in Grades 9 and 10 at two large Baltimore City public high schools underwent BP screening; those with BP persistently above the 85th percentile were randomly assigned to (a) 12 weeks daily PMR instruction provided in class for academic credit or (b) a control condition. The latter students had their BP measured at the same frequency as the PMR students and completed the PMR course during the following year. Approximately two thirds of eligible students entered and completed the study. Results demonstrated that treatment students (n = 51) enjoyed daily PMR, mastered the technique, and achieved reduced systolic BP at posttest relative to the untrained controls (n = 59). At follow-up 4 months later, group BP differences were not significant. Implications for use of PMR to promote cardiovascular health are discussed.