Does the Menstrual Cycle Play a Role in Sexual Arousal?

Menstrual cycle effects on erotic arousability were tested in 13 women aged 20–28. Vaginal blood volume and pulse amplitude were measured with a light emitting diode photoplethysmograph, labial temperature was measured by a small thermistor, and subject self-report of arousal was estimated on a 7-point Likert scale in response to audio erotic tapes and fantasy over five different phases of the menstrual cycle. Pre-session levels of blood volume and labial temperature showed no important changes across the cycle, but pooled blood volume, pulsatile blood volume and labial temperature reliably demonstrated sexual arousal during tape and fantasy sessions. Repeated measures analyses of variance and covariance of physiological change scores from baseline and subjective ratings failed to demonstrate that significant changes in self-reports, vaginal blood volume, vaginal pulse amplitude, or labial temperature occurred as a function of menstrual cycle phase. This study provides objective physiological evidence that there appears to be no one phase in the menstrual cycle during which women are more sexually arousable to erotic stimuli as detected by these physiological measures.     

Physiological and Subjective Sexual Arousal in Pre- and Postmenopausal Women and Postmenopausal Women Taking Replacement Therapy

Twenty premenopausal, 14 postmenopausal, and 14 postmenopausal women receiving replacement estrogen therapy were studied to determine whether differences in hormone status were associated with differences in physiological and subjective sexual responses. All subjects viewed a neutral, an erotic, and a second neutral videotape while photoplethysmographic vaginal pulse amplitude was continuously recorded. Self-report ratings of sexual arousal and affective response were collected. Serum levels of testosterone, estradiol, estrone, and luteinizing hormone were obtained. The three groups did not differ in either average or maximum vaginal pulse amplitude to the videotapes nor in latency of sexual response. The postmenopausal women not taking replacement estrogen reported significantly less vaginal lubrication in response to the erotic videotape than the higher estrogen premenopausal and replacement hormone groups. Estradiol level was significantly correlated with ratings of vaginal lubrication in response to the erotic videotape but not with vaginal pulse amplitude. Results thus suggest that estrogen is important in maintaining vaginal lubrication and the perception of sexual arousal but not in determining vaginal vasocongestion.     

The relationship between women's subjective and physiological sexual arousal

Previous literature presents discordant results on the relationship between physiological and subjective sexual arousal in women. In this study, the use of hierarchical linear modeling (HLM) revealed a significant concordance between continuous measures of physiological and subjective sexual arousal as assessed during exposure to erotic stimuli in a laboratory setting. We propose that past studies that have found little or no association between the two measures may have been in part limited by the methodology and statistical analyses employed.     

Vaginal and Pelvic Floor Responses to Sexual Stimulation

Vaginal vascular responses to vibratory stimulation of the clitoris, recorded as changes in the amplitude of oscillations of light reflectance at the heart-beat frequency, are: a) very repeatable, b) widespread throughout the vagina but of greater amplitude in its lower anterior wall than elsewhere, c) of very short latency (2–3 sec), but cumulative over 30 sec or more. Such responses are not imitated by raising the abdominal pressure, voluntarily contracting the pelvic floor or the flexors or adductors of the hips, or raising the blood pressure by exercise. They are absent in the foot, hand and rectum when present in the vagina. Sexual fantasy provokes vaginal responses very similar to those from vibratory stimulation of the clitoris, though somewhat less repeatable. Mean vaginal light reflectance, averaged over a cardiac cycle, responds to the same stimuli which affect the amplitude of pulsation. It is, however, much more subject to artifact. Changes in thermal conductivity closely parallel those in amplitude of oscillation of reflectance, with a time-lag which is probably mainly instrumental. Vibratory stimulation of the clitoris causes sustained reflex contraction of the pelvic floor. This reflex (never, it seems, previously described) may be regarded as a tonic counterpart of the well-known phasic bulbocavernosus reflex. The vascular events at and after orgasm and their relationship to features of the pelvic floor electromyogram are described and illustrated; the heart rate falls greatly during the 10 sec after orgasm, the amplitude of vaginal vascular pulsation remains above its prestimulation value for as long as 15 min, and pelvic floor electromyographic activity remains enhanced for at least 2 min.     

Thermistor Measurement of Male Sexual Arousal

Penile erection is accompanied by genital vasocongestion which increases penile skin temperature. These changes should be measurable using thermistors attached to the penis. The present study compared the UUT51J1 Uni-Curve thermistor placed on the penis with the Barlow strain gauge in the assessment of sexual arousal in 8 heterosexual males. Sexual stimuli consisted of 3, 3-min exposures to heterosexually explicit black-and-white videotapes. The results indicated that the two measures were highly positively correlated with each other and with self-report. However, the strain gauge followed detumescence more closely than the thermistor and was more strongly correlated with subjective arousal. Also, the two probes differed as to when they reached peak response. The strain gauge typically reached its highest point prior to the end of the film, while the thermistor always peaked during the early post-film interval. The thermistor's slow transition from temperature increases to decreases during the initial moments of detumescence appeared to be its principal shortcoming as a measure of male sexual arousal.     

Female Sexual Arousal and the Menstrual Cycle

Abstract

Self-reports of sexual arousal were significantly affected by conditions under which they were elicited. Such self-reports in women not taking oral contraceptives were congruent with a hormonal basis for such arousal only when the women were “unaware” that the study investigated sexual arousal as a function of the menstrual cycle. The “unaware” condition was operationalized by means of daily self-reports elicited from males and females for 11 weeks under the guise of a study of biological rhythms. A composite of one to three menstrual cycles for 26 women not taking oral contraceptives showed that sexual arousal during the luteal phase, when progesterone is relatively high, was significantly lower compared to peaks around ovulation, and premenstrual and late menstrual days (p<.02). For the “aware” condition, women were asked to remember moods for the premenstrual, menstruating and luteal phases of the very last cycle on which they had just finished giving “unaware” daily self-reports. A 2 × 3 analysis of variance (with “aware” versus “unaware” conditions and premenstrual, menstruating, and luteal phases of the last cycle as the two independent variables) yielded a significant interaction effect with F=6.5, df=2, 50, p<.003. In the “unaware” condition, sexual arousal was reported lowest during the luteal phase. The opposite pattern was reported in the “aware” condition. The results suggest that cyclical variability may not be simply due to women's misattribulions. However, “awareness” has an effect on self-report measures and may bias reports according to cultural stereotypes. Daily self-reports of sexual arousal for men were averaged over the duration of the study. This average was 3.16. The equivalent average for women not taking oral contraceptives was 2.35 and for women taking oral contraceptives was 2.62. Analysis of variance of these three means yielded a significant difference with F=4.49, df=2, 59, p<.02.     

The Relationship Between Sexual Arousal Experience and Genital Response

In studies of sexuality, there has been a wide divergence in findings concerning the correlation between the subjective and genital measurements of sexual arousal. The present study is aimed at helping clarify this situation by examining the role of certain factors involved in determining the subjective-genital correlation. Thus, the following study was designed to (1) employ a methodology aimed at improving the correlation between the subjective and genital measurements of arousal in women, and (2) determine the effect of attending to bodily cues upon the subjective-genital relationship. To accomplish this end, 36 female subjects were separated into two experimental groups and one control group. The experimental groups were given instructions suggesting that they attend to either genital or non-genital body signals of sexual arousal while viewing a series of 10 erotic slides. Subjects in the control group were given no attention instructions. Subjective levels of arousal to the erotic slides were scaled by having subjects set the intensity of sound and light to match their intensity of arousal (cross-modality matching) and by using a rating scale. Genital measures of sexual arousal consisted of measurement of vaginal pulse amplitude. Analyses revealed that group computed correlations were very high and that individually computed subjective-genital correlations were highest in the attention groups. Paying attention to bodily cues has a significant and positive effect on the subjective-genital relationship. Possible explanations for these results are given along with a discussion of the role of methodological variables in influencing the genital-subjective correlation. The finding of high levels of correlation raises doubts on the heretofore made assumption of low subjective-genital correlations for women.     

A Psychophysiological Exploration of Sexual Arousal Patterns in Females and Males

Fifty-nine female and 39 male undergraduates completed 3 sessions of a psychophysiological study on sexual arousal. Subjects were assigned to one of six experimental groups. Subjects within each group were exposed to a series of four audio-tapes, and were asked to fantasize before and after the tape series. Tapes varied in their erotic and romantic content, and two sex role dimensions were also varied across tapes. Dependent measures included scaled subjective reports, genital pulse amplitude and blood volume responses, heart rate, and finger pulse amplitude. Erotic contents were significantly more sexually arousing than nonerotic contents for both sexes. Romantic content did not significantly enhance the facilitation of sexual arousal. Nontraditional sex roles were significantly more arousing for females, with a similar nonsignificant trend for males. There were significant correlations between genital pulse amplitude and subjective reports of arousal; however, for females the genital blood volume measure showed less reliable agreement with subjective report. Genital pulse amplitude was the most reliable and precise indicator of arousal and accounted for the most variance across conditions. No significant changes occurred on the heart rate and finger pulse amplitude measures. Although subjects were able to become aroused by fantasy alone, listening to erotic tapes did not facilitate their ability to be sexually aroused during fantasy.     

Groin Skin Temperature: Testing the Validity of a Relatively Unobtrusive Physiological Measure of Psychosexual Arousal

The validity of groin skin temperature as a relatively unobtrusive physiological measure of psychosexual arousal was tested for both males and females. Groin skin temperature and hemodynamic (penile circumference, vaginal blood volume, and vaginal pulse amplitude) changes induced by erotic and non-erotic film presentations were monitored in 10 male and 10 female volunteers. Significant positive correlations (p<.001) between the measures were obtained for 16 of 20 subjects. Implications of the findings for detecting low levels of psychosexual arousal are discussed.     

Male Sexual Arousal and the Law of Initial Value

Penile circumference was measured for 24 men before and during exposure to erotic material of matched content presented in 5 modes: film, slides, spoken, written, and fantasy. Stimulation in each case involved 8, 2-min episodes graded in content from low to high heterosexual arousal value. Three indices were used to test for the Law of Initial Value (LIV). No consistent evidence was obtained that stimulation levels or change scores varied systematically with prestimulus baseline values. The data indicate that male sexual arousal can be investigated without the need to adjust change scores to take into account initial value, at least when guided relaxation has been used to stabilize basal rates.     

A Cognitive-Physiological Process Model of Sexual Arousal and Response

Three decades of research have focused on identifying cognitive and physiological processes in human emotion. The mechanisms by which these components interact to mediate sexual arousal are unknown, and scientific knowledge on women Is lacking. New findings have identified (a) key components of sexual response, (b) mechanisms by which cognitive and physiological processes form a feedback loop in the mediation of sexual arousal, and (c) a method to increase genital response and cognitive expectancy, via pairing general autonomic activation and physiological genital feedback. This approach interrupted the dysfunctional process and initiated a positive cognitive-physiological feedback loop of sexual arousal to levels comparable with sexually functional women within 3 min. This empirically derived process model identifies a cognitive-physiological pathway for sexual response, and a potential common pathway for emotion processing and an integrated behavioral medicine approach to women's health.     

Assessment of female sexual arousal: Response specificity and construct validity

Specificity of vaginal pulse amplitude and vaginal blood volume in reaction to visual sexual stimuli was investigated by comparing responses to sexual, anxiety-inducing, sexually threatening, and neutral film excerpts. Subjective sexual arousal, body sensations, emotional experience, skin conductance, and heart rate were monitored along with the genital measures. Self-report data confirmed the generation of affective states as intended. Results demonstrated response specificity of vaginal vasocongestion to sexual stimuli. In terms of both convergent and divergent validity, vaginal pulse amplitude was the superior genital measure. Skin conductance discriminated among stimuli only to a small degree, whereas heart rate failed to discriminate among stimuli altogether.     

Determinants of subjective experience of sexual arousal in women: Feedback from genital arousal and erotic stimulus content

Sixty-two women participated in a study designed to explore the association between gential and subjective sexual arousal. Four stimulus conditions were created, designed to evoke differential patterns of genital arousal over time. Subjects were instructed to report sensations in their genitalia while being exposed to the same erotic stimulus on repeated trials or to a series of varying erotic stimuli. Detection of genital arousal was facilitated by the occurrence of changes in genital arousal over trials. That is, genital and subjective sexual arousal were linearly related in conditions that resulted in large differences in genital arousal over trails, whereas such a relation was absent in conditions in which genital arousal levels remained relatively constant. In women, peripheral feedback from consciously detected genital arousal seems to be a relatively unimportant determinant of subjective sexual arousal.     

Testing cognitive predictors of individual differences in the sexual psychophysiological responses of sexually functional women

The literature on sexual responses shows a large and not fully understood between‐women variance in sexual responses and in strength of coherence between physiological and subjective sexual responses. This study investigated cognitive factors theorized to be associated with sexual responses that could explain such variance. Specifically, we investigated the predictive value of sexual excitation/inhibition and sexual schemas on sexual response and coherence. Vaginal photoplethysmography and continuous subjective sexual arousal were collected from 29 young women while they watched a control/erotic video sequence. Hierarchical linear modeling revealed that high sexual excitation and schemas related to passion and romance were related to higher coherence. These findings support the notion that cognitive factors that enhance sexual arousal contribute to the large variation seen in the coherence of sexual response as measured in the laboratory.     

Attentional Effects on Sexual Arousal

Lang's theory on emotions was applied to the sexual response: the cognitive processing of information on sexual responses (in contrast to information on sexual stimuli) was predicted to elicit the sexual response. Each of 48 men and 48 women imagined a sexual interaction, looked at a series of slides, and listened to an erotic story. Subjects were instructed to attend to images of sexual stimuli or to images of sexual stimuli plus responses. During imagery the genital response and the experience of sexual arousal were stronger when subjects focused on stimuli plus responses than when they focused on stimuli only. This effect occurred in both men and women. During slides and story a similar effect was found in men, but not in women. The genital response and the experience of sexual arousal were found to correlate more strongly when attentional focus was on stimuli plus responses instead of on stimuli only: in women, and, although marginally significant, also in men.     

Effects of fragrance on female sexual arousal and mood across the menstrual cycle

The effects of fragrance on sexual response in women were investigated using subjective and physiological measures of sexual arousal and of mood. Responses were obtained from female participants in three different fragrance conditions (female fragrance, male fragrance, and a "blank" or neutral substance), as they viewed erotic and sexually neutral films, and fantasized about sexual situations. Each woman was tested twice: during the midfollicular and periovulatory phases of her menstrual cycle. Menstrual cycle phase effects were apparent; self-report data indicated greater sexual arousal and more positive mood during the periovulatory than during the follicular phase. Results demonstrated a positive effect of the male fragrance on genital arousal during erotic fantasy, but this finding was apparent only during the follicular phase testing session. This effect did not appear to be mediated by any effects of fragrance on mood.     

Abdominal Temperature Changes During Male Sexual Arousal

The present study explored the feasibility of using temperature measurement from a non-genital location to assess sexual arousal. Based upon analyses conducted with thermographic techniques, it was hypothesized that abdominal skin cooling would occur during sexual arousal. In 2 sessions, 6 male subjects were shown low, moderate, and high arousing erotic films. Simultaneous measures of abdominal temperature, penile circumference, and subjective arousal were taken. Results indicate that while decreases in skin temperature were seen during arousal, thermister data did not correlate well with tumescence or subjective arousal ratings. It would appear that thermography and temperature measurement might be most fruitfully employed to explore basic physiological processes involved in sexual arousal, since continuous temperature measures do not appear sensitive enough for use in typical sex research paradigms.     

Male Sexual Arousal as a Function of the Content and the Vividness of Erotic Fantasy

Physiological and subjective arousal were measured across 5 sessions, each separated by a day or more, in which males attempted to induce erection through fantasy. Stable individual differences in the capacity to achieve voluntary enhancement of penile tumescence were found. The men who were most able to enhance erection were those who reported the greatest use of sexually arousing fantasy themes. In a second experiment, which employed structured rather than unstructured fantasy, sexual arousal was studied as a function of the content of fantasy and tbe vividness with which participants could form images (as assessed by Beits Q.M.I. Scale). Fantasy themes that had been independently rated as high in erotic value produced greater changes in penile circumference relative to baseline than themes of lower erotic value. Men with vivid imagery were more sexually aroused during fantasy than men with non-vivid imagery. The interaction between the content and vividness of fantasy was not significant. These results indicate that the extent to which men can induce erection through fantasy depends not only on the sexual themes that the men use during fantasy, but on the vividness of the images they form.     

Facial Electromyography: A Measure of Affective Processes During Sexual Arousal

Forty female volunteers participated in a study to investigate whether facial EMGs could be used as measures of affect during sexual arousal. Audiotaped narratives were used to induce the following affect-sexual states: 1) pleasant affect + sexual arousal, 2) unpleasant affect + sexual arousal, 3) pleasant affect + no sexual arousal, and 4) unpleasant affect + no sexual arousal. EMG activity was recorded bilaterally from the corrugator and zygomatic muscle regions. Corrugator muscle activity was significantly greater in response to the unpleasant stimulus conditions. This relationship held for both the non-sexual and sexual conditions, suggesting that corrugator muscle activity may provide a reliable index of negative affect during sexual arousal. Zygomatic activity was significantly greater during the sexual as compared to the non-sexual stimuli, but did not increase as a function of pleasant affect. Greater left than right corrugator muscle activity was observed in response to the sexual stimuli. Left muscle superiority was also noted for zygomatic muscle activity, in response to the sexual unpleasant stimulus. Issues related to the interpretation of lateralized muscle activity are discussed.