Free-living vertebrates likely encounter many stressors throughout their lifetime, from fighting off a predator to coping with unpredictable weather. As a result, vertebrates will mount an acute response to the stressors. Here, we outline previous research conducted in behavioral endocrinology and stress physiology as it relates to our research. We then discuss our study with white-crowned sparrows (Zonotrichia leucophrys) in Tioga Pass Meadow, in which we examined how the acute stress response affects foraging behavior 24 hours after a stressor. In birds that underwent a stress series, we found there to be a significant 57% decrease in foraging behavior 24 hours following the stressor. Additionally, we found no significant difference in foraging of unstressed birds during this same time frame. Our findings suggest that the acute stress response in this species causes a reduction in foraging activity 24 hours following a stressful event.

Mitral Valve Prolapse Syndrome (MVPS) is a benign psychosomatic cardiac condition that can severely impair one's quality of life. Symptoms targeted in this study include, atypical chest pain, palpitations, anxiety, panic, and shortness of breath.This study was undertaken to examine the effects of a diaphragmatic breathing intervention on the symptoms and underlying mechanism of dysautonomia in a small group of symptomatic females with MVPS. The intervention was based on both yoga theory and cardiorespiratory empirical studies.Seven of eight participant's completed the nine week study using a single subject multiple baseline design across subjects. Participant's began a respiratory retraining intervention, in a weekly staggered pair start, after the first week of baseline measurement. Respiratory training consisted of a four week training in diaphragmatic breathing with home practice three times a day.Autonomic, behavioral, and cognitive systems were assessed. Dependent measures included State and Trait Anxiety, Anxiety Sensitivity, a Symptom Checklist, and Respiratory Sinus Arrhythmia (RSA). RSA is a current noninvasive measure of parasympathetic tone. Data on thoracic and abdominal respiratory predominance, respiration rate, diet, exercise, and adherence were also gathered.Data were analyzed via visual inspection of trends and phase average changes. Treatment effect sizes were calculated for standardized measures to indicate the meaningfulness of change.Two of the seven participants demonstrated a decrease in total symptom frequencies over the course of intervention. One participant demonstrated a weekly progression of lowered state anxiety scores from baseline through intervention. In terms of phase averages, three participants showed a lowering of state anxiety. All seven participants demonstrated lowered trait anxiety scores from pre to post intervention. Two of the seven participants demonstrated a meaningful pre to post intervention decrease in anxiety sensitivity. Respiratory training was effective in stabilizing abdominal respiration. Results regarding vagal tone could not be determined due to unreliable ECG data.In general, results were poor with several inconsistencies. Adherence rates were low and it did not appear that a therapeutic level of change in respiration rate was achieved. Controlling respiration rate may be a critical factor in the therapeutic effectiveness of respiratory retraining interventions. / Department of Counseling Psychology and Guidance Services

Two investigations were conducted with collegiate golfers for separate, but related purposes. 1) To investigate the effects of a physical conditioning program (strength, power and flexibility training) on clubhead speed, consistency, and putting distance control. 2) To investigate the effects of 36 continuous holes of competitive golf on testosterone and cortisol response and their relation to performance.Study #1: Subjects were ten men and six women NCAA Division I golfers. Supervised strength, power, and flexibility training was performed 3 times per week for 11 weeks. Golf ball launch conditions, putting distance control, strength, power, and flexibility tests were conducted before and after training. Significant (p < 0.05) increases were noted for all strength, power, and flexibility tests. Clubhead speed increased significantly (1.6%) from pre to post training, equating to a 4.9-meter increase in driving distance. No significant differences were observed for clubface-angle or launch-angle deviation. Putting distance performance significantly improved for the men-only group (29.6%). Significant (p < .05) correlations resulted between clubhead speed and rotational power (r = 0.86) for the men-only group. Qualitative video analysis did not show any consistent trends in swing mechanics alterations. Eleven weeks of physical conditioning increased clubhead speed without a negative effect on consistency or putting distance control in intercollegiate men and women golfers. Study #2: Subjects were eight NCAA Division I men golfers. Saliva samples were taken 45 minutes prior to the round and after each hole during a 36-hole competition. Time matched baseline samples were collected. Six and 36-hole area under the curve (AUC) values were calculated for endocrine measures. Salivary cortisol increased by 111% (p < 0.05) during competition compared to baseline. Testosterone-to-cortisol ratio was significantly lower (45%) throughout the competition compared to baseline. Significant (p < 0.05) correlations resulted between: 36-hole AUC testosterone-to-cortisol ratio difference and 36-hole score (r = 0.82), CSAI-2 somatic anxiety and pre-round cortisol (r = 0. 81), testosterone (r = -0.80), and testosterone-to-cortisol ratio (r = -0.72). These results indicate a significant hormonal strain during 10 hours of competitive golf, low TIC ratio relation with low golf scores, and CSAI-2 relation with endocrine measures. / School of Physical Education

Thesis (MPsy(Clinical))--University of South Australia, 2002.

Thesis (MPsy(Clinical))--University of South Australia, 2002.

Maintenance of normal health requires an intact stress system capable of mounting the metabolic, autonomic, behavioural and motor responses required for coping with or avoiding physiological and pathological challenges. The neuroendocrine component of this response principally involves the hypothalamic-pituitary-adrenal (HPA) and sympatho-adrenomedullary (SAM) axes. Impaired regulation of these axes has been implicated in the pathogenesis and expression of numerous disease states, however, it has proved very difficult to reproducibly activate the HPA and SAM axes and no single test exists that can reliably and safely be used to study these systems in man. Carbon dioxide (CO2) is the principal regulator of respiration, acid-base balance and behavioural-state arousal in humans. Paradigms of CO2 inhalation have been used in psychiatric research to investigate panic and anxiety disorders, but evaluation of other components of the stress response to CO2 has not previously been performed. I hypothesised that a single breath of 35% CO2 would be a simple and reliable tool for the evaluation of the stress response in humans. A single breath of four doses of CO2 (5%, 25%, 35% and 50%) was administered to 9 healthy volunteers in a randomised, single blind fashion. Subjective symptoms of anxiety increased in a dose-dependent manner. Inhalation of a single breath of 35% CO2 stimulated significant ACTH (p = 0.006), noradrenaline (p < 0.0001), cortisol (p = 0.02) and prolactin (p = 0.002) release. It also provoked an acute pressor response and an associated bradycardia (p < 0.0001 for both). No significant habituation of psychological, HPA or cardiovascular responses was seen when this dose was repeated after one week (n = 10) or 6 months (n = 5). It was apparent that a single breath of 35% CO2 reliably and safely produced SAM and HPA axis activation and further studies were then undertaken to assess the mechanism by which the observed responses occurred and its potential clinical implications. Administration of naltrexone (an opiate antagonist) to 10 normal volunteers disinhibited the HPA axis (p < 0.0004), whilst administration of metyrapone (a cortisol synthesis inhibitor) significantly reduced baseline cortisol (p < 0.03) levels. However, this alteration in HPA axis activity had no effect on either cardiovascular or psychological responses. Further, in a study of 8 breastfeeding mothers (a state associated with physiological suppression of the HPA axis) suckling significantly reduced plasma cortisol levels compared with control (p = 0.002) and bottle-feeders (p = 0.003). Despite this cortisol, systolic blood pressure (SBP), heart rate and psychological responses to 35% CO2 were not affected

Thesis (Ph.D. )--Edith Cowan University, 2008. / Submitted to the Faculty of Computing, Health and Science. Includes bibliographical references.

Thesis (M.A.)--Texas State University--San Marcos, 2009. / Vita. Includes bibliographical references (leaves 45-50). Also available on microfilm.

Thesis (M.Sc.) - Carleton University, 2005. / Includes bibliographical references (p. 87-117). Also available in electronic format on the Internet.

Thesis (M.Sc.) - Carleton University, 2005. / Includes bibliographical references (p. 122-139). Also available in electronic format on the Internet.