The Brain Activation-based Sexual Image Classifier (BASIC): A sensitive and specific fMRI activity pattern for sexual image perception

Sexual stimuli processing is a key element in the repertoire of human affective and motivational states. Previous neuroimaging studies of sexual stimulus processing have revealed a complicated mosaic of activated regions, leaving unresolved questions about their sensitivity and specificity to sexual stimuli per se, generalizability across individuals, and potential utility as neuromarkers for sexual stimulus processing. In this study, data on sexual, negative, non-sexual positive, and neutral images from Wehrum et al. (2013) (N = 100) were re-analyzed with multivariate Support Vector Machine models to create the Brain Activation-based Sexual Image Classifier (BASIC) model. This model was tested for sensitivity, specificity, and generalizability in cross-validation (N = 100) and an independent test cohort (N = 18; Kragel et al. 2019). The BASIC model showed highly accurate performance (94-100%) in classifying sexual versus neutral or nonsexual affective images in both datasets. Virtual lesions and test of individual large-scale networks (e.g., ‘visual’ or ‘attention’ networks) show that these individual networks are neither necessary nor sufficient to capture sexual stimulus processing. These findings suggest that brain responses to sexual stimuli constitute a category of mental event that is distinct from general affect and involves multiple brain networks. It is, however, largely conserved across individuals, permitting the development of neuromarkers for sexual processing in individual persons. Future studies could assess performance of BASIC to a broader array of affective/motivational stimuli and link brain responses with physiological and subjective measures of sexual arousal.

Serotonergic, Dopaminergic, and Noradrenergic Modulation of Erotic Stimulus Processing in the Male Human Brain

Human sexual behavior is mediated by a complex interplay of cerebral and spinal centers, as well as hormonal, peripheral, and autonomic functions. Neuroimaging studies identified central neural signatures of human sexual responses comprising neural emotional, motivational, autonomic, and cognitive components. However, empirical evidence regarding the neuromodulation of these neural signatures of human sexual responses was scarce for decades. Pharmacological functional magnetic resonance imaging (fMRI) provides a valuable tool to examine the interaction between neuromodulator systems and functional network anatomy relevant for human sexual behavior. In addition, this approach enables the examination of potential neural mechanisms regarding treatment-related sexual dysfunction under psychopharmacological agents. In this article, we introduce common neurobiological concepts regarding cerebral sexual responses based on neuroimaging findings and we discuss challenges and findings regarding investigating the neuromodulation of neural sexual stimulus processing. In particular, we summarize findings from our research program investigating how neural correlates of sexual stimulus processing are modulated by serotonergic, dopaminergic, and noradrenergic antidepressant medication in healthy males.

PENGARUH SINDROMA DEPRESI TERHADAP DISFUNGSI EREKSI

Normal sexual function is a bio-psycho-social process which is significantly related to the quality of life (QOL). Any disturbance in one of the components can be a disaster in sexual life. Erectile dysfunction is a disability to get an erection or to maintain the erection well enough for a sexual intercourse, which persists or recurs at least three months conse-cutively due to either psychogenic or organic disturbances, or both. Some psychogenic dis-turbances especially depression, anxiety, and relational distress, play some important roles in ED. Besides that, aging, low testoteron level, physical diseases, and some certain medicines have to be included. Key words: erection, erectile dysfunction, sexual stimulus, depression. Abstract: Fungsi seksual yang normal merupakan suatu proses biopsikososial yang berkaitan langsung dengan kualitas hidup. Adanya gangguan pada salah satu komponen dapat menjadi malapetaka bagi kehidupan seksual. Disfungsi ereksi dapat dedefinisikan sebagai suatu keti-dakmampuan untuk ereksi atau mempertahankan ereksi yang cukup untuk melakukan hu-bungan seksual yang memuaskan, yang menetap atau berulang paling tidak selama tiga bulan berturut-turut. Gangguan psikogenik khususnya sindroma depresi, ankietas, dan distres relasional berperan penting dalam hal terjadinya disfungsi ereksi. Disamping itu usia lanjut, rendahnya kadar testoteron, penyakit fisik, dan beberapa jenis obat perlu diperhitungkan. Kata kunci: fisiologi ereksi, disfungsi ereksi, stimulus seksual, depresi.

A Rump Sexuality: The Recurrence of Defecating Horses in Beckett's Oeuvre

Through the examination of the recurrent sexualised image of horses' posteriors in the act of defecation in , , and this paper outlines a nexus of concepts clustering around this apparently aberrant sexual stimulus. Using Freud's case history of Little Hans and the suggested relationship between defecation and childbirth as an analogue, the paper argues that the image reveals not a horror at sexuality within Beckett's works, but a horror at reproductive sexuality which finds its fullest expression in the sterile world of

Cultural Differences in Preferences for Shapes

It was predicted that since there is less sexual restraint in Jamaica the sex difference in shape preference should be larger for native adult Jamaicans than Caymanian adults. Pairs of drawings of a “female” and a “male” object, depicted according to the theory of sexual symbolism, were shown to 200 subjects, who indicated which of each pair they preferred. The larger sex difference found among Jamaicans was interpreted in terms of primary sexual stimulus generalization.

Matching to Reinforcer Value: Human Concurrent Variable-Interval Performance

A male paedophile offender chose between pairs of sexual stimulus classes in a two-operandum procedure with reinforcement arranged according to concurrent variable-interval variable-interval schedules. Condition 1 involved choice between slides of women and slides of men; condition 2, slides of men vs. slides of children; and condition 3, slides of women vs. slides of children. On the assumption that the subject matched his ratios of responses and times on the two operanda to reinforcer value, estimates were obtained from the data in conditions 1 and 2 of the values of slides of women and of children relative to slides of men. These yielded predictions of the relative allocations of responses and of time in condition 3. The predicted and obtained outcomes were similar. The results support the use of matching-based scaling of reinforcer values in the prediction of choice between qualitatively different reinforcers and extend the application to a human subject, the two-operandum procedure, and sexual stimuli.

The contact sex pheromone of Pardosa lapidicina Emerton (Araneida: Lycosidae)

Laboratory bioassays of male courtship behavior in Pardosa lapidicina indicate that the contact sex pheromone is associated with the silk dragline deposited on the substratum by mature females. The pheromone is quickly inactivated by water. It appears to represent a facultative sexual stimulus, and can be by-passed if the male first touches the female.

Sexual Initiating Behaviour By Female Rhesus Monkeys (Macaca Mulatta) Under Laboratory Conditions

Observations were made on oppositely-sexed pairs of adult rhesus monkeys during 60-min tests when females were both intact (215 tests) and ovariectomized (196 tests). Three special gestures, named the hand-reach, head-duck and head-bob were described in female rhesus monkeys, and evidence is put forward that, like the well-known "presentation" gesture, they too served as female sexual invitations. They occurred most frequently immediately before and during the mounting sequence and ceased abruptly after the male's ejaculation. Although individually less effective than presentations in stimulating mounting by males, hand-reaches, head-ducks and head-bobs together initiated a larger total number of mounts: thus, they were important invitational gestures. Ovariectomy resulted in a dramatic decrease in the numbers of these sexual invitations as female receptivity declined. Hand-reaches, head-ducks and head-bobs possessed some of the stereotyped properties of reflexes and, unlike presentations, never occurred in non-sexual behavioural situations or in response to a non-sexual stimulus (e.g. male threat) ; they may thus provide a more direct indication of the female's motivational state.