Haemodynamic brain response to visual sexual stimuli is different between homosexual and heterosexual men.
ABSTRACT The underlying neurobiological factors involved in sexual orientation are largely unknown. This study investigated whether neural circuits or different cognitive processes accounted for differences in brain activation in 14 heterosexual and 14 homosexual males. Brain scans were undertaken in each subject using functional magnetic resonance imaging while they viewed different sexual stimuli, i.e. heterosexual couple stimuli (HCS), gay couple stimuli (GCS), lesbian couple stimuli (LCS) and neutral stimuli (NS). Ratings of sexual attractiveness of the stimuli were assessed. Subjective sexual arousal was induced by HCS and GCS in heterosexual and homosexual men, respectively. Sexual disgust was induced by GCS and LCS in heterosexual and homosexual men, respectively. Compared with viewing NS, viewing sexual stimuli induced significantly different brain activations, most of which had the characteristics of cognitive processes. These observations suggest that different cognitive patterns may be the major cause of different subjective responses to sexual stimuli between heterosexual and homosexual men.
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ABSTRACT: What's known on the subject? and What does the study add? Cerebral lateralization/specialization is a neurophysiological feature that has been documented regarding somatic, psychological and sexual functioning and that may be manifested in differences in hand preference, cognitive style, gonadal hormonal effects and possibly even sexual orientation. In this study we investigated a possible cerebral lateralization effect on sexual response for dihydrotestosterone, using finasteride as a hormone-blocking compound. The results of this study differ substantially from other studies examining the effects of finasteride on sexual response, presumably due to the greater restrictions we placed on defining relevant sexual activity, to our alerting patients to both positive and negative sexual effects and to the fact that we assessed the effects separately in right-handed vs left-handed patients. Handedness, as a proxy for cognitive style and possible lateralization of effect/function, appears to be a relevant factor when considering the sexual effects of specific gonadal hormones. OBJECTIVE: • To investigate the relationships between pharmacologically induced deprivation of dihydrotestosterone, sexual arousal, libido and hand preference, by comparing the self-reported sexual response prior to and during reception of the anti-androgen finasteride in men undergoing treatment for male pattern baldness. PATIENTS AND METHOD: • In total, 33 sexually healthy Romanian men participated in this study. • Patients prospectively provided information regarding their sexual functioning (over 4 weeks), as measured by the International Index of Erectile Function (IIEF) prior to and after commencing treatment with 1 mg finasteride for male pattern baldness. RESULTS: • Overall IIEF scores as well as the erectile function, orgasmic function, sexual desire and overall satisfaction subscales showed group, treatment and group by treatment effects. • The intercourse satisfaction subscale showed group and group by treatment effects. • On most subscales, right-handed men showed no effect or lower sexual function whereas left-handed men reported no effect or improved sexual function, primarily. CONCLUSIONS: • These results suggest that the sexual effects of dihydrotestosterone deprivation may depend on handedness - a proxy variable that may represent cognitive style - which lends further support to the idea of two distinct neuroendocrine psychosexual axes. • They further suggest that detection of such sexual effects may be enhanced by using research methodologies and communication strategies that increase patients' sensitization to such effects.BJU International 11/2012; 111(4B). DOI:10.1111/j.1464-410X.2012.11580.x · 3.13 Impact Factor
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ABSTRACT: Factors related to sexual arousal are different in men and women. The conditions for women to become aroused are more complex. However, the conventional audio-visual stimulation (AVS) materials used to evaluate sexual arousal are universal. In the present study, we investigated sexual differences in the response to different types of AVS by studying activated areas of the brain using functional magnetic resonance imaging (fMRI). fMRI was performed during two types of AVS in 20 healthy heterosexual volunteers (aged 20-28 years, 10 men and 10 women). The two AVS types were: (1) mood type, erotic video clips with a concrete story and (2) physical type, directly exposing sexual intercourse and genitalia. fMRI images were analyzed and compared for each stimulation with a Mann-Whitney U test, with statistical significance set at P<0.05. Men preferred the physical type of AVS to the mood type (mean arousal score 2.14 vs 1.86 in females) and women preferred the mood type (mean arousal score 2.14 vs 1.86 in males) (P<0.05). Degrees of activation in brain areas differed between genders and types of AVS for each gender. This should be considered when applying the AVS method to evaluate and diagnose female sexual dysfunction.International Journal of Impotence Research advance online publication, 10 January 2013; doi:10.1038/ijir.2012.47.International journal of impotence research 01/2013; 25(4). DOI:10.1038/ijir.2012.47 · 1.37 Impact Factor
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ABSTRACT: Research on the processing of sexual stimuli has proved that such material has high priority in human cognition. Yet, although sex differences in response to sexual stimuli were extensively discussed in the literature, sexual orientation was given relatively little consideration, and material suitable for relevant research is difficult to come by. With this in mind, we present a collection of 200 erotic images, accompanied by their self-report ratings of emotional valence and arousal by homo- and heterosexual males and females (n = 80, divided into four equal-sized subsamples). The collection complements the Nencki Affective Picture System (NAPS) and is intended to be used as stimulus material in experimental research. The erotic images are divided into five categories, depending on their content: opposite-sex couple (50), male couple (50), female couple (50), male (25) and female (25). Additional 100 control images from the NAPS depicting people in a non-erotic context were also used in the study. We showed that recipient sex and sexual orientation strongly influenced the evaluation of erotic content. Thus, comparisons of valence and arousal ratings in different subject groups will help researchers select stimuli set for the purpose of various experimental designs. To facilitate the use of the dataset, we provide an on-line tool, which allows the user to browse the images interactively and select proper stimuli on the basis of several parameters. The NAPS ERO image collection together with the data are available to the scientific community for non-commercial use at http://naps.nencki.gov.pl.Frontiers in Psychology 08/2015; 6:1336. DOI:10.3389/fpsyg.2015.01336 · 2.80 Impact Factor