Observing Erotic Videos with Heterosexual Content Induces Different Cerebral Responses in Homosexual and Heterosexual Men

To determine the cerebral functionality associated with the perception and processing of erotic stimuli in men with different sexual orientation, this work evaluated the electroencephalographic activity (EEG) from several cortical areas, as well as subjective arousal in homosexual and heterosexual men during observation of an erotic film with heterosexual content. The heterosexual men rated the erotic video with higher general and sexual arousal than the homosexual participants. During observation of the neutral and erotic videos, both groups showed a decreased amplitude of the alpha band in prefrontal and parietal cortices, indicating increased attention. When watching the erotic video, the homosexual men showed an increased amplitude of the theta and fast bands only in the prefrontal cortex, which could be related to the cognitive processing of the erotic stimulus. These EEG results should broaden our knowledge of the cortical mechanisms related to the different perception and processing of erotic stimuli in men with different sexual orientations.

Observing Erotic Videos With Heterosexual Content Induces Different Cerebral Responses in Homosexual and Heterosexual Men

To determine the cerebral functionality associated with the perception and processing of erotic stimuli in men with different sexual orientation, this work evaluated the electroencephalographic activity (EEG) from several cortical areas, as well as subjective arousal in homosexual and heterosexual men during observation of an erotic film with heterosexual content. The heterosexual men rated the erotic video with higher general and sexual arousal than the homosexual participants. During observation of the neutral and erotic videos, both groups showed a decreased amplitude of the alpha band in prefrontal and parietal cortices, indicating increased attention. When watching the erotic video, the homosexual men showed an increased amplitude of the theta and fast bands only in the prefrontal cortex, which could be related to the cognitive processing of the erotic stimulus. These EEG results should broaden our knowledge of the cortical mechanisms related to the different perception and processing of erotic stimuli in men with different sexual orientations.

Visual Sexual Stimuli-Cue or Reward? A Perspective for Interpreting Brain Imaging Findings on Human Sexual Behaviors

There is an increasing number of neuroimaging studies using visual sexual stimuli (VSS), especially within the emerging field of research on compulsive sexual behaviors (CSB). A central question in this field is whether behaviors such as excessive pornography consumption share common brain mechanisms with widely studied substance and behavioral addictions. Depending on how VSS are conceptualized, different predictions can be formulated within the frameworks of Reinforcement Learning or Incentive Salience Theory, where a crucial distinction is made between conditioned and unconditioned stimuli (related to reward anticipation vs. reward consumption, respectively). Surveying 40 recent human neuroimaging studies we show existing ambiguity about the conceptualization of VSS. Therefore, we feel that it is important to address the question of whether VSS should be considered as conditioned stimuli (cue) or unconditioned stimuli (reward). Here we present our own perspective, which is that in most laboratory settings VSS play a role of reward, as evidenced by: (1) experience of pleasure while watching VSS, possibly accompanied by genital reaction; (2) reward-related brain activity correlated with these pleasurable feelings in response to VSS; (3) a willingness to exert effort to view VSS similarly as for other rewarding stimuli such as money; and (4) conditioning for cues predictive of VSS. We hope that this perspective article will initiate a scientific discussion on this important and overlooked topic and increase attention for appropriate interpretations of results of human neuroimaging studies using VSS.

Women's interest in visual sexual stimuli varies with menstrual cycle phase at first exposure and predicts later interest

This study investigated whether women's interest in visual sexual stimuli varied with their hormonal state. Viewing times of 30 women, 15 normal cycling (NC) and 15 oral contracepting (OC), to sexually explicit photos were measured at three different times. NC women were tested during their menstrual, periovulatory, and luteal phases, and OC women were tested at equivalent temporal intervals. Subjects viewed stimuli as long as desired, thus viewing time measured subject interest. Subjective ratings of stimulus sexual attractiveness were obtained on each test. There was no overall relationship between menstrual cycle phase and viewing time. However the participant's menstrual cycle phase during first exposure to sexual stimuli predicted subsequent interest in sexual stimuli during the next two tests. NC women who first viewed stimuli during their periovulatory phase looked longer at the sexual stimuli across all sessions than did women first tested in their luteal phase. OC women first exposed to the sexual stimuli during menstruation looked longer at the stimuli across all sessions than did OC women first exposed at other test phases. Neither current test phase nor initial cycle phase influenced subjective ratings. Women had increased interest in sexual stimuli across all sessions if first exposed to sexual stimuli when endogenous estrogens were most likely highest. These data suggest that women's interest in visual sexual stimuli is modulated by hormones such that the hormonal condition at first exposure possibly determines the stimuli's emotional valence, markedly affecting subsequent interest in sexual stimuli.