Caffeine substantially affects cardiovascular functioning, yet wide variability exists in caffeine control procedures in cardiovascular reactivity (CVR) research. This study was conducted in order to identify a minimal abstention duration in habitual coffee consumers whereby CVR is unconfounded by caffeine; Six hours was hypothesized (average half-life). Thirty nine subjects (mean age: 20.9; 20 Women) completed a repeated measures study involving hand cold pressor (CP) and memory tasks. Caffeinated and decaffeinated coffee were administered. The following CV indices were acquired during baseline, task, and recovery epochs prior to coffee intake, 30 minutes-, and six hours post-intake: Heart rate (HR), high frequency heart rate variability (hfHRV), root mean squared successive differences (RMSSD), systolic and diastolic blood pressures (SBP, DBP), mean arterial pressure (MAP), pre-ejection period (PEP), left ventricular ejection time (LVET), and total peripheral resistance (TPR). Results support the adequacy of a six-hour abstention in controlling for caffeine-elicited CVR changes. The current study contributes to methodological endeavors in psychophysiology. Further investigations are crucial in establishing ideal caffeine controls, which would promote increasingly valid and reliable cross-study results. / Master of Science

The association between cardiovascular reactivity and the metabolic syndrome, as well as individual metabolic syndrome criterion variables, was investigated in adolescents. Cardiovascular reactivity has been examined as a risk marker or factor in the pathogenesis of hypertension or cardiovascular disease, but few studies have looked at its relationship with the metabolic syndrome. Blood pressure (BP) and heart rate (HR) cardiovascular reactivity to three tasks, evaluated speaking, mirror star tracing, and cold pressor, were assessed in 148 adolescents. Using the American Heart Association (AHA) adult definitional criteria, individuals were classified into metabolic syndrome groups (presence vs. absence of metabolic syndrome), and 16% of individuals met criteria for the metabolic syndrome. In logistic regression analyses, the occurrence of the metabolic syndrome was negatively associated with HR reactivity to the cold pressor (OR = 0.920, 95% CI = 0.873, 0.969), and positively associated with diastolic blood pressure (DBP) reactivity to the star tracing task (OR = 1.089, 95% CI = 1.008, 1.177). Results of multiple regression analyses that included individual metabolic syndrome risk variables indicated that cold pressor reactivity explained 7% of the variance in casual BP, while star tracing reactivity accounted for 7% of the variance waist circumference and 6% of the variance triglycerides (ps < .05). The findings indicate that cardiovascular reactivity to physical or behavioral challenge is associated with the metabolic syndrome in a sample of adolescents. Cardiovascular reactivity may be an important clinical tool for identifying individuals at risk of the metabolic syndrome and cardiovascular disease.

This experiment tested three hypotheses regarding right cerebral involvement in hostility and physiological arousal. First, replication of previous research indicating heightened physiological responding to stress among high hostile individuals was attempted. Second, high hostile individuals were predicted to an increased tendency toward right hemisphere dominance following exposure to a stressor. Third, high hostile individuals were expected to maintain their physiological arousal and shift in cerebral laterality longer than the low-hostile comparison group. Low- and high-hostile participants (25 males per group, drawn from the undergraduate Psychology pool) were identified using the Cook-Medley Hostility Scale (CMHS). Physiological measures (SBP, DBP, HR) were recorded at baseline, as were results from a dichotic listening procedure. Participants were then administered the cold-pressor procedure, and physiological recordings were taken again. Dichotic listening procedures were then administered 3 consecutive times to monitor for shifts in cerebral laterality. After the final dichotic listening procedure, physiological measures were taken once again to determine recovery rates. Results did not support the a priori hypotheses. Specifically, low-hostile individuals were consistently higher on the physiological measures when compared to the high-hostiles. The predicted maintenance of increased physiological arousal was also not supported by the data. Neuropsychological measures also failed to differentiate between the groups, and failed to demonstrate the predicted shift in cerebral laterality. / Master of Science

The aim of the current study was to examine how thinking about qualitatively different social network members may differentially affect cardiovascular reactivity to a subsequent stressor. Eighty-two undergraduates were asked to think and write about different types of relationships preceding a social stressor. No differences between conditions in CVR were found during social support induction phase or the stressor task. Women in the supportive condition were found to have slower SV recovery than those in the ambivalent condition. The results of this study are inconsistent with previous evidence for a relationship between mental representations of social ties and CVR. Future research should seek to rule out confounding variables and clarify this effect.

No description available.

This study examined how smoking and stress interact to affect the reactivity of the cardiovascular system. Findings revealed that subjects who smoked first and who were then exposed to stress showed less cardiovascular reactivity (CVR) to stress compared to non-smoking subjects exposed only to stress. However, the combination of smoking and stress led to higher absolute levels and greater reactivity for all cardiovascular measures compared to stress alone. The ability for trait hostility, state angry affect and state anxious-affect to predict CVR to smoking and stress was also examined. State anxious-affect was the only affect-related variable that predicted CVR across experimental phases for both smokers and non-smokers. None of the affect-related variables were able to predict CVR during smoking. Trait hostility and state anxious-affect predicted CVR to stress for smokers and non-smokers. Trait hostility was negatively associated with CVR to stress, while state anxious-affect was positively associated with CVR to stress. State angry affect did not predict CVR to stress after accounting for the effects due to trait hostility.

Due to the universal nature of stress, and its impact on physical health, it is important to understand how it is related to other psychological variables. The current study was undertaken in order to investigate whether an individual's cardiovascular reactivity to stress is impacted by their level of experiential avoidance, as measured by the Acceptance and Action Questionnaire (AAQ-II). Individuals who are experientially avoidant are more likely to attempt to escape or prevent certain experiences and make effort to change them or avoid the contexts in which they occur. Previous research has indicated that experiential avoidance is related to some measures of physiological stress. One hundred twenty-eight college students (ages 18-29) were administered a questionnaire that included measures of general stress, experiential avoidance, and depression. After completing the questionnaire, a baseline reading of cardiovascular activity was taken. After that baseline reading, research assistants administered the Trier Social Stress Test (TSST), a series of tasks designed to induce physiological stress that consists of an anticipation period, a speech, and a math task. Measurements of cardiovascular activity were taken throughout administration. It was hypothesized that increased experiential avoidance would predict higher blood pressure and heart rate both before engaging in the stress task. It was also hypothesized that increased experiential avoidance would predict higher cardiovascular reactivity during administration of the TSST. As was expected, higher experiential avoidance predicted higher baseline heart rate. This finding adds to the body of research that supports the connection between psychological constructs and physiological reactivity. However, experiential avoidance did not significantly predict baseline blood pressure or any measures of physiological reactivity during the TSST.

No description available.

This experiment tested hypotheses linking the right cerebral regulation of hostility and cardiovascular reactivity. First, replication of previous research supporting heightened cardiovascular reactivity (mean arterial pressure, systolic blood pressure, diastolic blood pressure, and heart rate) among high-hostile participants was attempted. Second, dynamic variations in functional cerebral asymmetry in response to pain (cold pressor stressor) and affective verbal learning (positive and negative valenced word lists) were measured. High- and low-hostile participants (n = 64) were identified using the Cook Medley Hostility Scale. Participants completed either the cold-pressor stressor condition or the no-stress control condition as well as the negative and the positive affective verbal learning test. Cardiovascular measures (MAP, SBP, DBP, and HR) before and after the stress or no-stress condition and before and after the negative and the positive affective learning tasks were recorded. The results demonstrated that high-hostiles had difficulty processing emotional stimuli. High-hostiles were reliably impaired in emotional word learning. Further, results suggested that negative affective learning produced proactive interference for the learning or recall of subsequently presented information. Positive affective learning produced diametrically opposite effects with retroactive interference for the recall of previously presented information. Also, high-hostiles' cardiovascular reactivity to a physical stressor was independent of the valence of the learning task. In contrast, low-hostiles' cardiovascular reactivity was valence dependent with activation to both the positive list concurrent with stress and to the negative list concurrent with no stress. Finally, the results indicated that the effect of the affective learning lists, on the heart, is stress dependent. Neuropsychological theories of ANS regulation and emotion are discussed in relation to the primary findings and a new model of lateralized regulation is proposed. / Ph. D.

No description available.