Lisa Dawn Hamilton
Mount Allison University
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Featured researches published by Lisa Dawn Hamilton.
Physiology & Behavior | 2008
Lisa Dawn Hamilton; Matthew L. Newman; Carol L. Delville; Yvon Delville
Peer victimization in the form of bullying is a chronic social stressor experienced by many humans during development. Exposure to bullying has been associated with a variety of mental disorders, such as anxiety and depression. Participants pre-selected for the presence or absence of a history of being bullied were brought into a laboratory and placed in a stressful situation. Blood pressure, heart rate, and salivary cortisol levels were measured before the introduction of the stressor (Time 1), at the end of the stressor (Time 2), and after its removal (Time 3). Men with a history of exposure to frequent bullying showed blunted blood pressure responses at Time 2 compared to control men. Bullied and Non-bullied women did not show any differences in any of the measures. Men and women in both groups showed an increase in heart rate in response to the stressor. There were no significant differences in salivary cortisol levels between Bullied and Non-bullied participants. However, salivary cortisol levels and systolic blood pressure were lower in Bullied male participants who reported having no feelings of anger about their experience compared to controls and those who did report anger. These data show altered sympathetic responses to stress in men with a history of victimization as well as suggesting long-term effects on the HPA axis in the most affected individuals.
Psychophysiology | 2012
Tierney A. Lorenz; Christopher B. Harte; Lisa Dawn Hamilton; Cindy M. Meston
There is increasing evidence that womens physiological sexual arousal is facilitated by moderate sympathetic nervous system (SNS) activation. Literature also suggests that the level of SNS activation may play a role in the degree to which SNS activity affects sexual arousal. We provide the first empirical examination of a possible curvilinear relationship between SNS activity and womens genital arousal using a direct measure of SNS activation in 52 sexually functional women. The relationship between heart rate variability (HRV), a specific and sensitive marker of SNS activation, and vaginal pulse amplitude (VPA), a measure of genital arousal, was analyzed. Moderate increases in SNS activity were associated with higher genital arousal, while very low or very high SNS activation was associated with lower genital arousal. These findings imply that there is an optimal level of SNS activation for womens physiological sexual arousal.
The Journal of Sexual Medicine | 2008
Lisa Dawn Hamilton; Alessandra H. Rellini; Cindy M. Meston
INTRODUCTION Theoretically, the physiological response to stress should inhibit the sexual response. This has been demonstrated experimentally in animal models, and correlationally in studies of human reproduction. It is reasonable to expect, then, that the stress response would be blunted during sexual arousal, and several researchers have found a pattern of decreasing cortisol during sexual arousal. AIM In the present study, we explored individual differences in womens cortisol response to sexual arousal in a laboratory setting. We also examined how cortisol response in the laboratory related to a validated measure of sexual arousal functioning in real life. MAIN OUTCOME MEASURES Cortisol levels were measured in saliva via enzyme immunoassay. Subjective arousal was measured by a self-report questionnaire, and genital arousal was measured by a vaginal photoplethysmograph. METHODS Subjective and physiological responses to an erotic film were assessed in 30 women. Saliva samples were taken at baseline and following the film. RESULTS The majority of women (N = 20) showed a decrease in cortisol; nine women showed an increase in response to an erotic film. The women who showed an increase in cortisol had lower scores on the Arousal, Desire, and Satisfaction domains of the Female Sexual Function Index. Genital arousal in the laboratory was not related to cortisol change. CONCLUSIONS Women who show an increase in cortisol in response to sexual stimuli in the laboratory have lower levels of functioning in certain areas of their sexual life compared with women who show a decrease in cortisol. Stress related to sexual performance may interfere with sexual arousal.
The Journal of Sexual Medicine | 2008
Lisa Dawn Hamilton; Emily A. Fogle; Cindy M. Meston
INTRODUCTION Several studies have demonstrated that moderate exercise increases genital response to erotic stimuli in women. The increase in genital arousal could be the result of various changes that can occur in response to exercise including changes in hormone levels, neurotransmitter levels, mood, and autonomic nervous system activity. AIM The present study was an attempt to shed light on two such mechanisms through which exercise enhances sexual arousal. METHOD Sixteen participants came into the lab on two separate occasions: during one visit, they filled out questionnaires for 20 minutes, and during the other visit, they exercised on a treadmill for 20 minutes. The questionnaires and exercise were both followed by the presentation of a neutral then erotic film during which the womens physiological sexual arousal was measured. Saliva samples were taken at baseline, prefilm, and postfilm. Main Outcome Measures. Subjective arousal was measured using a self-report questionnaire, and genital arousal was measured by a vaginal photoplethysmograph. Testosterone and alpha-amylase (a marker of sympathetic nervous system [SNS] activity) were measured via saliva assays. RESULTS Findings replicated previous studies showing a significant increase in physiological sexual arousal with exercise. There was a significant increase in alpha-amylase across the study in the exercise condition, but not in the no-exercise condition. There were no differences in testosterone levels between the exercise and no-exercise conditions. CONCLUSIONS SNS activity is one mechanism through which exercise increases genital sexual arousal. Testosterone does not mediate the relationship between exercise and genital sexual arousal.
The Journal of Sexual Medicine | 2009
Cindy M. Meston; Lisa Dawn Hamilton; Christopher B. Harte
INTRODUCTION Womens motivations to engage in sex are likely influenced by their past sexual experiences, the type of relationship in which they are involved in, and numerous lifestyle factors such as career and family demands. The influences of these factors undoubtedly change as women age. AIM This study aimed to examine potential differences in sexual motivation between three distinct age groups of premenopausal women. METHODS Women aged 18-22 years (N = 137), 23-30 years (N = 103), and 31-45 years (N = 87) completed an online survey that assessed the proportion with which they had engaged in sexual intercourse for each of 140 distinct reasons. MAIN OUTCOME MEASURES The YSEX? Questionnaire by Meston and Buss [1] was used to measure sexual motivation. The items of this questionnaire were composed of four primary sexual motivation factors (physical, goal attainment, emotional, insecurity), and 13 subfactors. RESULTS Women aged 31-45 years reported a higher proportion of engaging in sex compared with one or both of the younger age groups of women for nine of the 13 YSEX? subfactors: stress reduction, physical desirability, experience seeking, resources, social status, revenge, expression, self-esteem boost, and mate guarding. At an item level, the top 25 reasons for having sex were virtually identical across age groups. CONCLUSION Women aged 31-45 have more motives for engaging in sex than do women aged 18-30, but the primary reasons for engaging in sex do not differ within this age range. Women aged 18-45 have sex primarily for pleasure, and love and commitment. The implications for diagnosis and treatment of women with sexual dysfunctions were discussed.
Hormones and Behavior | 2011
Lisa Dawn Hamilton; Cindy M. Meston
Stress and anxiety are commonly thought to be detrimental to sexual function. Several studies in both the human and animal literature, however, have found that inducing anxiety can enhance sexual function in women. The mechanisms that explain a negative relationship between physical and psychological stress and sexual functioning are well documented, but little is known about how stress or anxiety might have a facilitatory effect on sexual arousal. As an initial step in exploring the relationship between anxiety and sexual arousal, the present study examined the role of the autonomic nervous system, and the adrenal hormones cortisol and dehydroepiandrosterone-sulfate (DHEA-S) in response to a sexual film, an anxiety-inducing film, and a humorous film. Nineteen premenopausal women (mean age 24.4 years) who were free from sexual difficulties came into the lab on three separate days. At each session they were shown an anxiety-inducing, sexually arousing, or humorous (control) film while their physiological arousal was measured. They also provided saliva samples before and after each film. Cortisol significantly decreased, while DHEA-S increased in the sexual and humorous conditions. Neither hormone changed significantly in the anxiety-inducing condition. Autonomic nervous system activity measured by heart rate and heart rate variability did not change in response to the sexual or anxiety-inducing films, but heart rate variability increased significantly in response to the humorous film. The cortisol/DHEA-S ratio at the post-sexual film time point was significantly negatively correlated with genital arousal (measured by vaginal pulse amplitude). Anxiety-inducing films did not result in a physiological stress response, which can explain why they do not impair sexual function.
Journal of Traumatic Stress | 2009
Alessandra H. Rellini; Lisa Dawn Hamilton; Yvon Delville; Cindy M. Meston
Many women with a history of childhood sexual abuse (CSA) experience difficulties becoming sexually aroused. This study measured cortisol and physiological sexual arousal during exposure to sexual stimuli in women with and without a history of CSA. Childhood sexual abuse survivors showed a smaller decrease in cortisol during sexual arousal than the nonsexually abused, control group potentially due to an increase in cortisol in some of the participants in the CSA group. Physiological sexual arousal was weaker in CSA survivors compared to women with no history of sexual abuse and posttraumatic stress disorder symptoms showed characteristics consistent with mediation for the relationship between a history of CSA and inhibited sexual arousal responses.
Hormones and Behavior | 2010
Lisa Dawn Hamilton; Cindy M. Meston
The present study examined whether womens testosterone levels are influenced by being with a sexual and romantic partner after a period of sexual abstinence. Women in long distance relationships (n=15) provided five saliva samples: at least 1 week before seeing their partner (and at least 2 weeks since their last visit), the day before seeing their partner, when they were with their partner but prior to engaging in sexual activity, the day after their first sexual activity, and 3 days after they were separated from their partners. Salivary testosterone was lowest when participants had been away from their partners for at least 2 weeks and highest the day before they were to see their partners and the day after sexual activity. Results from this study indicated that womens testosterone increased both the day before they were with their partners and they day after they first engaged in sexual activity. However, something about initially reuniting with their partners returned their testosterone to baseline levels, which may be an effect of being in the same location as a partner, or just a state fluctuation due to nervousness or other psychological state.
Journal of Sex & Marital Therapy | 2014
Lisa Dawn Hamilton; Amanda M. Julian
Psychological stressors can interfere with sexual function through psychological and physiological mechanisms. Chronic stress, in particular, seems to have a negative effect on sexual functioning for men and women. The present study was designed to identify categories of stressors that contribute to sexual difficulties as well as assess the role of anxiety and depression in the relationship between stress and sexual function. Participants were recruited for an online survey in which they completed questionnaires on daily stressors, anxiety, depression, and sexual function. Results indicated that daily stressors predicted lower scores on sexual satisfaction for men and women and sexual activity for women. These effects were mediated by scores on the depression scale. Daily stressors, depression, and anxiety were highly correlated. A factor analysis of stressors resulted in 5 distinct categories of stressors. Of these, financial stressors and stressors related to low socioeconomic status were related to lower scores on all aspects of sexual functioning for women but not for men. Womens sexual functioning scores were more strongly related to stress and depression than mens scores. Results suggest that contextual factors (e.g., daily stressors, depression) are important considerations when assessing problems with sexual functioning.
PLOS ONE | 2015
Diana S. Fleischman; Lisa Dawn Hamilton; Daniel M. T. Fessler; Cindy M. Meston
Sexual arousal is a motivational state that moves humans toward situations that inherently pose a risk of disease transmission. Disgust is an emotion that adaptively moves humans away from such situations. Incongruent is the fact that sexual activity is elementary to human fitness yet involves strong disgust elicitors. Using an experimental paradigm, we investigated how these two states interact. Women (final N=76) were assigned to one of four conditions: rate disgust stimuli then watch a pornographic clip; watch a pornographic clip then rate disgust stimuli; rate fear stimuli then watch a pornographic clip; or watch a pornographic clip then rate fear stimuli. Women’s genital sexual arousal was measured with vaginal photoplethysmography and their disgust and fear reactions were measured via self-report. We did not find that baseline disgust propensity predicted sexual arousal in women who were exposed to neutral stimuli before erotic content. In the Erotic-before-Disgust condition we did not find that sexual arousal straightforwardly predicted decreased image disgust ratings. However, we did find some evidence that sexual arousal increased self-reported disgust in women with high trait disgust and sexual arousal decreased self-reported disgust in women with low trait disgust. Women who were exposed to disgusting images before erotic content showed significantly less sexual arousal than women in the control condition or women exposed to fear-inducing images before erotic content. In the Disgust-before-Erotic condition the degree of self-reported disgust was negatively correlated with genital sexual arousal. Hence, in the conflict between the ultimate goals of reproduction and disease avoidance, cues of the presence of pathogens significantly reduce the motivation to engage in mating behaviors that, by their nature, entail a risk of pathogen transmission.