Men and women differ in amygdala response to visual sexual stimuli

A hypothalamic-amygdala circuit underlying sexually dimorphic aggression

Male animals often display higher levels of aggression than females. However, the neural circuitry mechanisms underlying this sexually dimorphic aggression remain elusive. Here, we identify a hypothalamic-amygdala circuit that mediates male-biased aggression in mice. Specifically, the ventrolateral part of the ventromedial hypothalamus (VMHvl), a sexually dimorphic region associated with eliciting male-biased aggression, projects densely to the posterior substantia innominata (pSI), an area that promotes similar levels of attack in both sexes of mice. Although the VMHvl innervates the pSI unidirectionally through both excitatory and inhibitory connections, it is the excitatory VMHvl-pSI projections that are strengthened in males to promote aggression, whereas the inhibitory connections that reduce aggressive behavior are strengthened in females. Consequently, the convergent hypothalamic input onto the pSI leads to heightened pSI activity in males, resulting in male-biased aggression. Our findings reveal a sexually distinct excitation-inhibition balance of a hypothalamic-amygdala circuit that underlies sexually dimorphic aggression.

Beyond faces: the contribution of the amygdala to visual processing in the macaque brain

The amygdala is present in a diverse range of vertebrate species, such as lizards, rodents, and primates; however, its structure and connectivity differs across species. The increased connections to visual sensory areas in primate species suggests that understanding the visual selectivity of the amygdala in detail is critical to revealing the principles underlying its function in primate cognition. Therefore, we designed a high-resolution, contrast-agent enhanced, event-related fMRI experiment, and scanned 3 adult rhesus macaques, while they viewed 96 naturalistic stimuli. Half of these stimuli were social (defined by the presence of a conspecific), the other half were nonsocial. We also nested manipulations of emotional valence (positive, neutral, and negative) and visual category (faces, nonfaces, animate, and inanimate) within the stimulus set. The results reveal widespread effects of emotional valence, with the amygdala responding more on average to inanimate objects and animals than faces, bodies, or social agents in this experimental context. These findings suggest that the amygdala makes a contribution to primate vision that goes beyond an auxiliary role in face or social perception. Furthermore, the results highlight the importance of stimulus selection and experimental design when probing the function of the amygdala and other visually responsive brain regions.

Women and men with distressing low sexual desire exhibit sexually dimorphic brain processing

Distressing low sexual desire, termed Hypoactive Sexual Desire Disorder (HSDD), affects approximately 10% of women and 8% of men. In women, the 'top-down' theory of HSDD describes hyperactivity in higher-level cognitive brain regions, suppressing lower-level emotional/sexual brain areas. However, it is unknown how this neurofunctional disturbance compares to HSDD in men. To investigate this, we employed task-based functional MRI in 32 women and 32 men with HSDD to measure sexual-brain processing during sexual versus non-sexual videos, as well as psychometric questionnaires to assess sexual desire/arousal. We demonstrate that women had greater activation in higher-level and lower-level brain regions, compared to men. Indeed, women who had greater hypothalamic activation in response to sexual videos, reported higher psychometric scores in the evaluative (r = 0.55, P = 0.001), motivational (r = 0.56, P = 0.003), and physiological (r = 0.57, P = 0.0006) domains of sexual desire and arousal after watching the sexual videos in the scanner. By contrast, no similar correlations were observed in men. Taken together, this is the first direct comparison of the neural correlates of distressing low sexual desire between women and men. The data supports the 'top-down' theory of HSDD in women, whereas in men HSDD appears to be associated with different neurofunctional processes.

The characteristics of sexual behavior in blind men in Ganzhou, China: A cross-sectional study

Visual stimuli play key roles in influencing men sexual behavior. However, few studies have explored the sexual behavior of blind men. To provide more information about blind men for the study of andrology by surveying the characteristics of their current sexual behavior. A questionnaire-based cross-sectional study design was performed. The questionnaire contained questions regarding demographic characteristics of participants, access to sexual knowledge, perception of the sexual partners' beauty, and sexual arousal. Blind men were interviewed face-to-face by the trained investigator. Complete questionnaires were collected from 54 participants, with an average age of 40.57 ± 9.80 years old. Eye diseases were the most frequent cause of blindness. In terms of sexual orientation, all participants were heterosexual. Notably, 90.7% of the participants reported to have had a sexual experience. Among those who had engaged in sexual behavior, 93.6% experienced sexual pleasure and 69.4% had a normal erectile function. Overall, 16.7% of the participants received sex education. The participants obtained sexual knowledge mainly through sounds from mobile phones, peer-to-peer communication, sounds of television and radio. Voice was the most frequent perception of the sexual partners' beauty, followed by figure, skin, and body fragrance. In terms of stimuli of sexual arousal, tactile sensation and auditory sensation in that order were the most frequent stimuli of sexual arousal. Stimuli of sexual arousal in blind men are mainly mediated by sound and touch. Blind men understand their sexual partners' beauty through auditory, tactile, and olfactory sensations. Blind men in Ganzhou lack formal and systematic sex education.

Sexual dysfunction among patients with Parkinson's disease: A systematic review and meta-analysis

BACKGROUND

Previous studies have reported a higher prevalence of sexual dysfunction (SD) in patients with Parkinson's disease (PD). In the current study, we aimed to conduct a systematic review and meta-analysis to investigate the role of PD as a potential risk factor for SD in both genders.

METHODS

We performed a comprehensive search on PubMed, Embase, Scopus, and Web of Science. All observational studies comparing the prevalence of SD in PD with the general population were included.

RESULTS

After screening 22 studies were included in our qualitative and statistical analysis. We included 13 studies that reported odds ratio (OR) and found a significant association between PD and SD (pooled OR = 3.5, 95% CI = 2.19-5.58). Five studies included only male patients and reported an OR of 3.34 (95% CI = 1.34-8.35; heterogeneity I2 = 81%, Tau2 = 0.79, p < 0.00), while seven studies included both sexes and reported an OR of 3.55 (95% CI = 1.89-6.66; heterogeneity I2 = 78%, Tau2 = 0.53, p < 0.00).

CONCLUSION

In conclusion, our study suggests a strong association between PD and SD in both men and women. Our analysis of 22 observational studies reveals that the prevalence of sexual dysfunction is significantly higher in patients with PD compared to the general population. These findings highlight the importance of addressing SD as part of the comprehensive management of patients with PD.

The puritanical moral contract: Purity, cooperation, and the architecture of the moral mind

Commentators raise fundamental questions about the notion of purity (sect. R1), the architecture of moral cognition (sect. R2), the functional relationship between morality and cooperation (sect. R3), the role of folk-theories of self-control in moral judgment (sect. R4), and the cultural variation of morality (sect. R5). In our response, we address all these issues by clarifying our theory of puritanism, responding to counter-arguments, and incorporating welcome corrections and extensions.

When the brain turns on with sexual desire: fMRI findings, issues, and future directions

INTRODUCTION

More than 2 decades of neuroimaging research has sought to uncover the neurologic basis of sexual desire. However, the lack of a clear conceptual distinction between sexual desire and sexual arousal or even a broadly accepted definition of sexual desire has led to confusion in the literature regarding brain areas uniquely associated with sexual desire.

OBJECTIVES

(1) To critically review the neuroimaging literature that seeks to identify brain areas and networks involved in sexual desire; (2) to identify and discuss those brain areas and potential networks that are most promising for providing insights to sexual desire; and (3) to offer recommendations for future studies.

METHODS

Existing meta-analyses were used as a starting point to identify relevant neuroimaging studies on sexual desire, arousal, and love. This base was then expanded via Google Scholar and forward citation tracking of already identified studies.

RESULTS

Brain areas that are commonly associated with sexual desire and arousal include the amygdala, hypothalamus, dorsal and ventral striatum, anterior cingulate, insula, and prefrontal and orbitofrontal cortex. However, because the same basic paradigm has been used to study sexual desire and arousal, unambiguous conclusions regarding areas uniquely involved in sexual desire cannot be drawn. Moreover, the lack of connectivity analyses and a failure to acknowledge negative BOLD (blood-oxygen level dependent) significantly limit conclusions on the neural basis of sexual desire.

CONCLUSION

Five recommendations are made. First, stimulus types (ie, erotic vs sexually explicit) should be selected by the meaningful theoretical conceptualization of the constructs of interest. Second, participants should be provided with definitions of sexual desire, mental sexual arousal, and perceived genital sexual arousal, so they can choose which terms best describe their experience. Third, event-related designs should be used with caution when investigating sexual desire. Fourth, time series analyses should be used to identify both positive and negative BOLD. Fifth, connectivity analyses should be performed to identify brain networks.

Dynamic segregation and integration of brain functional networks associated with emotional arousal

The organization of brain functional networks dynamically changes with emotional stimuli, but its relationship to emotional behaviors is still unclear. In the DEAP dataset, we used the nested-spectral partition approach to identify the hierarchical segregation and integration of functional networks and investigated the dynamic transitions between connectivity states under different arousal conditions. The frontal and right posterior parietal regions were dominant for network integration whereas the bilateral temporal, left posterior parietal, and occipital regions were responsible for segregation and functional flexibility. High emotional arousal behavior was associated with stronger network integration and more stable state transitions. Crucially, the connectivity states of frontal, central, and right parietal regions were closely related to arousal ratings in individuals. Besides, we predicted the individual emotional performance based on functional connectivity activities. Our results demonstrate that brain connectivity states are closely associated with emotional behaviors and could be reliable and robust indicators for emotional arousal.

Prenatal androgen influences on the brain: A review, critique, and illustration of research on congenital adrenal hyperplasia

Sex hormones, especially androgens, contribute to sex and gender differences in the brain and behavior. Organizational effects are particularly important because they are thought to be permanent, reflecting hormone exposure during sensitive periods of development. In human beings, they are often studied with natural experiments in which sex hormones are dissociated from other biopsychosocial aspects of development, such as genes and experiences. Indeed, the greatest evidence for organizational effects on sex differences in human behavior comes from studies of females with congenital adrenal hyperplasia (CAH), who have heightened prenatal androgen exposure, female-typical rearing, and masculinized toy play, activity and career interests, spatial skills, and some personal characteristics. Interestingly, however, neuroimaging studies of females with CAH have revealed few neural mechanisms underlying these hormone-behavior links, with the exception of emotion processing; studies have instead shown reduced gray matter volumes and reduced white matter integrity most consistent with other disease-related processes. The goals of this narrative review are to: (a) describe methods for studying prenatal androgen influences, while offering a brief overview of behavioral outcomes; (b) provide a critical methodological review of neuroimaging research on females with CAH; (c) present an illustrative analysis that overcomes methodological limitations of previous work, focusing on person-specific neural reward networks (and their associations with sensation seeking) in women with CAH and their unaffected sisters in order to inform future research questions and approaches that are most likely to reveal organizational hormone effects on brain structure and function.

Pattern recognition reveals sex-dependent neural substrates of sexual perception

Sex differences in brain activity evoked by sexual stimuli remain elusive despite robust evidence for stronger enjoyment of and interest toward sexual stimuli in men than in women. To test whether visual sexual stimuli evoke different brain activity patterns in men and women, we measured hemodynamic brain activity induced by visual sexual stimuli in two experiments with 91 subjects (46 males). In one experiment, the subjects viewed sexual and nonsexual film clips, and dynamic annotations for nudity in the clips were used to predict hemodynamic activity. In the second experiment, the subjects viewed sexual and nonsexual pictures in an event-related design. Men showed stronger activation than women in the visual and prefrontal cortices and dorsal attention network in both experiments. Furthermore, using multivariate pattern classification we could accurately predict the sex of the subject on the basis of the brain activity elicited by the sexual stimuli. The classification generalized across the experiments indicating that the sex differences were task-independent. Eye tracking data obtained from an independent sample of subjects (N = 110) showed that men looked longer than women at the chest area of the nude female actors in the film clips. These results indicate that visual sexual stimuli evoke discernible brain activity patterns in men and women which may reflect stronger attentional engagement with sexual stimuli in men.

Distinct Emotional and Cardiac Responses to Audio Erotica between Genders

Emotional and cardiac responses to audio erotica and their gender differences are relatively unclear in the study of the human sexual response. The current study was designed to investigate gender differences regarding positive and negative emotional responses to erotica, as well as its association with cardiac response. A total of 40 healthy participants (20 women) were exposed to erotic, neutral, and happy audio segments during which emotions and heart rate changes were evaluated. Our data showed distinct emotional responses to erotica between genders, in which women reported a higher level of shame than men and rated erotic audios as less pleasant than happy audios. Meanwhile, men reported erotic and happy audios as equally pleasant. These results were independent of cardiac changes, as both sexes demonstrated comparable heart rate deceleration when exposed to erotica relative to neutral and happy stimuli. Our results highlight the role of sociocultural modulation in the emotional response to erotica.

Neuroelectric Correlates of Human Sexuality: A Review and Meta-Analysis

Many reviews on sexual arousal in humans focus on different brain imaging methods and behavioral observations. Although neurotransmission in the brain is mainly performed through electrochemical signals, there are no systematic reviews of the electrophysiological correlates of sexual arousal. We performed a systematic search on this subject and reviewed 255 studies including various electrophysiological methods. Our results show how neuroelectric signals have been used to investigate genital somatotopy as well as basic genital physiology during sexual arousal and how cortical electric signals have been recorded during orgasm. Moreover, experiments on the interactions of cognition and sexual arousal in healthy subjects and in individuals with abnormal sexual preferences were analyzed as well as case studies on sexual disturbances associated with diseases of the nervous system. In addition, 25 studies focusing on brain potentials during the interaction of cognition and sexual arousal were eligible for meta-analysis. The results showed significant effect sizes for specific brain potentials during sexual stimulation (P3: Cohen's d = 1.82, N = 300, LPP: Cohen's d = 2.30, N = 510) with high heterogeneity between the combined studies. Taken together, our review shows how neuroelectric methods can consistently differentiate sexual arousal from other emotional states.

A motivation model of sex addiction - Relevance to the controversy over the concept

An integrative model of sexual addiction is presented, involving a combination of models based upon (i) incentive motivation theory and (ii) the dual organisation of the control of behavior. The model is related to ongoing arguments about the validity of the notion of addiction when applied to sexual behavior. It is suggested that the evidence strongly favors the viability of an addiction model of sex. Strong similarities to the classical addiction to hard drugs are observed and features can be better understood with the help of the model. These include tolerance, escalation and withdrawal symptoms. It is argued that other candidates for accounting for the phenomena, such as obsessive-compulsive behavior, faulty impulse control, high drive and hypersexuality do not fit the evidence. The role of dopamine is central to the model. The model's relevance to stress, abuse, development, psychopathy, fantasy, sex differences, evolutionary psychology and the interaction with drug-taking is shown.

The association between Parkinson's disease and Sexual dysfunction: Clinical correlation and therapeutic implications

Sexual function which comprises of desire, arousal, orgasm and satisfaction and pain, involves coordinated physiologic responses from multiple different pathways. Sexual dysfunction (SD) occurs when these domains of the sexual response cycle are affected. SD is a common but under-recognized non-motor feature in Parkinson's disease (PD), a common age-related neurodegenerative disorder. SD significantly affects the quality of life of PD patients and their partners. Advanced age, gender, hormone deficiency, neuropsychiatric and medical comorbidities contribute to SD in PD. Possible potential pathological mechanisms include vasculogenic, endocrinologic, neurogenic and psychogenic factors. Various therapeutic interventions, both pharmacological and non-pharmacological modalities have been suggested to improve SD in PD. However, erectile dysfunction (ED) is the only SD with evidence-based treatment available. Non-pharmacological therapies are also offering promising evidence in the improvement of SD. A multidisciplinary approach in the assessment, investigation, and treatment is needed to address the real life complex issues (gender and comorbidities, neurobiological, vasoactive, hormonal as well as psychosocial aspects). Future clinical studies with validated and standardized methods in assessing SD as well as experimental models will be necessary for better insight into the pathophysiology. This would facilitate appropriate therapy and improve sexual rehabilitation in PD patients.

The role of steroid hormones in the sexual differentiation of the human brain

Widespread sex differences in human brain structure and function have been reported. Research on animal models has demonstrated that sex differences in brain and behavior are induced by steroid hormones during specific, hormone sensitive, developmental periods. It was shown that typical male neural and behavioral characteristics develop under the influence of testosterone, mostly acting during perinatal development. By contrast, typical female neural and behavioral characteristics may actually develop under the influence of estradiol during a specific prepubertal period. This review provides an overview of our current knowledge on the role of steroid hormones in the sexual differentiation of the human brain. Both clinical and neuroimaging data obtained in patients with altered androgen levels/actions (i.e., congenital adrenal hyperplasia or complete androgen insensitivity syndrome [CAIS]), point to an important role of (prenatal) androgens in inducing typical male neural and psychosexual characteristics in humans. In contrast to rodents, there appears to be no obvious role for estrogens in masculinizing the human brain. Furthermore, data from CAIS also suggest a contribution of sex chromosome genes to the development of the human brain. The final part of this review is dedicated to a brief discussion of gender incongruence, also known as gender dysphoria, which has been associated with an altered or less pronounced sexual differentiation of the brain.

Neuroscience and CSR: Using EEG for Assessing the Effectiveness of Branded Videos Related to Environmental Issues

The majority of studies evaluating the effectiveness of branded CSR campaigns are concentrated and base their conclusions on data collection through self-reporting questionnaires. Although such studies provide insights for evaluating the effectiveness of CSR communication methods, analysing the message that is communicated, the communication channel used and the explicit brain responses of those for whom the message is intended, they lack the ability to fully encapsulate the problem of communicating environmental messages by not taking into consideration what the recipients’ implicit brain reactions are presenting. Therefore, this study aims to investigate the effectiveness of CSR video communications relating to environmental issues through the lens of the recipients’ implicit self, by employing neuroscience-based assessments. For the examination of implicit brain perception, an electroencephalogram (EEG) was used, and the collected data was analysed through three indicators identified as the most influential indicators on human behaviour. These three indicators are emotional valence, the level of brain engagement and cognitive load. The study is conducted on individuals from the millennial generation in Thessaloniki, Greece, whose implicit brain responses to seven branded commercial videos are recorded. The seven videos were a part of CSR campaigns addressing environmental issues. Simultaneously, the self-reporting results from the participants were gathered for a comparison between the explicit and implicit brain responses. One of the key findings of the study is that the explicit and implicit brain responses differ to the extent that the CSR video communications’ brain friendliness has to be taken into account in the future, to ensure success. The results of the study provide an insight for the future creation process, conceptualisation, design and content of the effective CSR communication, in regard to environmental issues.

Effect of Relationship Status on Response Times to Sexual and Romantic Stimuli Among Japanese Undergraduates in a Memory Task

This study examined the effects of relationship status on response times to sexual and romantic stimuli during a memory task, which has not been studied before. Based on previous studies on sexual attitudes and behaviors, we hypothesized that response times to sexual stimuli would be faster in individuals who were in a relationship, compared to those who were not. We also hypothesized that the response times to sexual stimuli of individuals who were not in a relationship would be slower than their response time to romantic stimuli. A total of 348 college students memorized 27 sexual, romantic, and neutral sentences and were later asked to recognize them. The students' response times to each sentence were recorded. The results of a 2 (gender) × 2 (stimulus type) × 2 (relationship status) ANOVA showed that response times to sexual sentences were faster in participants who were in a relationship, compared to those who were not. Furthermore, participants who were not in a relationship responded more slowly to sexual than to romantic sentences. Thus, our hypotheses were supported. Individuals' relationship status influenced their response times to sexual and romantic stimuli even after controlling for the effects of gender.

The Role of Gender in the Association Among the Emotional Intelligence, Anxiety and Depression

Recent epidemiological data show an increase of depression and anxiety that cause a loss of about 3-4% of the gross domestic product in Europe, as a consequence of a reduced productivity and a premature death of people. Gender differences in both psychopathologies were found from mid-to-late adolescence until 55 years, and data indicate an increase of depression in women. Considering these data, new interventions focused on promoting psychological well-being were designed. A predictive factor of psychological disorders is Emotional Intelligence (EI), the ability to understand and regulate our own emotions, as well as those of others. EI is associated with psychological well-being, as well as with the treatment of mental illness, but gender differences in the association among EI, anxiety and depression remains unclear. The present study aims at analyzing the nomological associations among EI, anxiety and depression. Furthermore, the possible moderating role of gender in the relation between EI, depression and anxiety is investigated in a sample of 1725 healthy participants. Our results show that the ability to recognize and to control emotions in the social context helps us to reduce the risk to be affected by depression and anxiety. Moreover, our study shows that the association of EI with anxiety and depression wasn't gender moderated. In conclusion, the findings highlight that EI can help people to manage emotions linked to negative events and to successfully understand emotions in others. In addition, we found no moderation role of gender in the association between EI, anxiety and depression.

Abnormal Functional Connectivity Between the Left Medial Superior Frontal Gyrus and Amygdala Underlying Abnormal Emotion and Premature Ejaculation: A Resting State fMRI Study

Introduction

Premature ejaculation (PE) is a common sexual dysfunction and is found to be associated with abnormal emotion. The amygdala plays an important role in the processing of emotion. The process of ejaculation is found to be mediated by the frontal-limbic neural circuits. However, the correlations between PE and emotion are still unclear.

Methods

Resting-state functional magnetic resonance imaging (rs-fMRI) data were acquired in 27 PE patients with stable emotion (SPE), 27 PE patients with abnormal emotion (NPE), and 30 healthy controls (HC). We used rs-fMRI to explore the underlying neural mechanisms in SPE, NPE, and HC by measuring the functional connectivity (FC). Differences of FC values among the three groups were compared when choosing bilateral amygdala as the regions of interest (ROIs). We also explored the correlations between the brain regions showing altered FC values and scores of the premature ejaculation diagnostic tool (PEDT)/Eysenck Personality Inventory about neuroticism (EPQ-N) in the PE group.

Results

When the left amygdala was chosen as the ROI, the SPE group exhibited an increased FC between the left medial superior frontal gyrus (SFGmed) and amygdala compared with the NPE or HC group. When the right amygdala was chosen as the ROI, the NPE group exhibited a decreased FC between the left SFGmed and right amygdala compared with the HC group. In addition, FC values of the left SFGmed had positive correlations with PEDT and negative correlations with EPQ-N scores in the PE group. Moreover, FC values of the left superior temporal gyrus had positive correlations with EPQ-N scores in the PE group.

Conclusion

The increased FC values between the left SFGmed and amygdala could reflect a compensatory cortical control mechanism with the effect of stabilized emotion in the limbic regions of PE patients. Abnormal FC between these brain regions could play a critical role in the physiopathology of PE and could help us in dividing PE into more subtypes.

Validation of the Sexual Inhibition/Sexual Excitation Scales (SIS/SES) in Italy: Assessing Gender and Age Differences of Sexual Functioning

The Sexual Inhibition Scales and Sexual Excitation Scales (Janssen et al., 2002a), based on the dual control model by Bancroft and Janssen (2000), are part of a 45-item self-report questionnaire evaluating individual tendencies to sexual inhibition or excitation according to three factors: two inhibition factors, SIS1, threat of performance failure, and SIS2, threat of performance consequences, and one excitation factor, SES. In this paper, we aimed to validate and explore psychometric properties of the SIS/SES in a sample of 2260 Italian men and women aged 18 to 75 years. Confirmatory factor analyses showed that the three-factor structure proposed in the original version of the scales fit with our sample. Moreover, our data confirmed the results of the original validation sample: Women scored higher on the SIS and lower on the SES than men did, but no significant differences appeared in the factor scores by age group, except for a gender × age interaction, where younger women had higher SIS2 scores. The SIS/SES appeared to be an effective, appropriate cross-cultural measurement of human sexuality in Italian samples, also shedding light on sexual arousal differences in women and men in our country. We also discuss clinical and therapeutic aspects.

Deep learning for sex classification in resting-state and task functional brain networks from the UK Biobank

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Applied deep learning to sex classification in UK BioBank fMRI connectomes.

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Deep learning classifies sex better in resting-state than in task fMRI.

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Algorithm to balance out multiple confounds from an fMRI dataset.

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Adapted two deep learning visualization methods to fMRI connectome classification.

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Analyzed role of three brain a priori networks in sex classification.

Classification of whole-brain functional connectivity MRI data with convolutional neural networks (CNNs) has shown promise, but the complexity of these models impedes understanding of which aspects of brain activity contribute to classification. While visualization techniques have been developed to interpret CNNs, bias inherent in the method of encoding abstract input data, as well as the natural variance of deep learning models, detract from the accuracy of these techniques. We introduce a stochastic encoding method in an ensemble of CNNs to classify functional connectomes by sex. We applied our method to resting-state and task data from the UK BioBank, using two visualization techniques to measure the salience of three brain networks involved in task- and resting-states, and their interaction. To regress confounding factors such as head motion, age, and intracranial volume, we introduced a multivariate balancing algorithm to ensure equal distributions of such covariates between classes in our data. We achieved a final AUROC of 0.8459. We found that resting-state data classifies more accurately than task data, with the inner salience network playing the most important role of the three networks overall in classification of resting-state data and connections to the central executive network in task data.

Altered Structural and Functional Connectivity Contribute to Rapid Ejaculation: Insights from a Multimodal Neuroimaging Study

Little is known about how the aberrant structural and functional connectivity relates to the rapid ejaculation. Data of diffusion tensor imaging and resting state functional magnetic resonance imaging were acquired from 32 PE patients and 38 healthy controls (HCs). Firstly, we investigated the structural connectivity (SC) disruptions of PE patients using the method of graph theoretical analysis. Brain regions with impaired nodal strength were then defined as regions of interest (ROI). Secondly, the corresponding functional connectivity (FC) changes were explored. Finally, the correlation analyses were performed between brain areas with abnormal connectivity and clinical characteristics. Structural analysis revealed that PE patients had increased nodal strength in the right superior frontal gyrus (dorsolateral), left middle frontal gyrus, right superior frontal gyrus (medial), right superior frontal gyrus (medial orbital) and decreased nodal strength in the left amygdala. FC analysis revealed that PE patients had decreased FC values in the default mode network, visual recognition network and subcortical network, as well as increased FC values in the attention network. Moreover, correlation analysis revealed that the nodal strength of right superior frontal gyrus (dorsolateral) was negatively associated with the intra-vaginal ejaculation latency, while FC values between the left middle frontal gyrus and middle occipital gyrus were positively related to the total scores of the premature ejaculation diagnostic tool (PEDT). Our results indicated that PE might be associated with the abnormal SC of areas in the prefrontal-amygdala pathway and aberrant FC in certain functional brain networks, especially in default mode network.

Understanding heterosexual women's erotic flexibility: the role of attention in sexual evaluations and neural responses to sexual stimuli

Many women experience desires, arousal and behavior that run counter to their sexual orientation (orientation inconsistent, 'OI'). Are such OI sexual experiences cognitively and neurobiologically distinct from those that are consistent with one's sexual orientation (orientation consistent, 'OC')? To address this question, we employed a mindful attention intervention-aimed at reducing judgment and enhancing somatosensory attention-to examine the underlying attentional and neurobiological processes of OC and OI sexual stimuli among predominantly heterosexual women. Women exhibited greater neural activity in response to OC, compared to OI, sexual stimuli in regions associated with implicit visual processing, volitional appraisal and attention. In contrast, women exhibited greater neural activity to OI, relative to OC, sexual stimuli in regions associated with complex visual processing and attentional shifting. Mindfully attending to OC sexual stimuli reduced distraction, amplified women's evaluations of OC stimuli as sexually arousing and deactivated the superior cerebellum. In contrast, mindfully attending to OI sexual stimuli amplified distraction, decreased women's evaluations of OI stimuli as sexually arousing and augmented parietal and temporo-occipital activity. Results of the current study constrain hypotheses of female erotic flexibility, suggesting that sexual orientation may be maintained by differences in attentional processing that cannot be voluntarily altered.

Smaller volume and altered functional connectivity of the amygdala in patients with lifelong premature ejaculation

OBJECTIVES

To analyze the abnormal amygdala structure and function in lifelong premature ejaculation (PE) patients compared with healthy controls (HCs).

METHODS

Forty-four lifelong PE patients and thirty-one HCs were enrolled in this study. Each subject was diagnosed with PE using a Premature Ejaculation Diagnostic Tool (PEDT) and intravaginal ejaculation latency time (IELT) score. Based on t-tests and Pearson correlation analysis, the voxel-based morphometry and functional connectivity (FC) analyses were applied to evaluate brain structural and functional changes by using T1-weighted and resting-state functional magnetic resonance imaging scans.

RESULTS

Lifelong PE patients had decreased gray matter volume in the bilateral amygdala and increased FC between the amygdala and precuneus, posterior cingulate cortex (PCC), and middle temporal cortex (MTC), as well as decreased FC between the amygdala and precentral gyrus, insula, and inferior frontal gyrus. Moreover, significantly negative correlations between the IELT score and the mean z-score from amygdala-MTC (r = -0.49) and amygdala-PCC (r = -0.48) FC were found in lifelong PE patients.

CONCLUSIONS

Our study investigated the abnormal amygdala-related structure and connectivity patterns in PE patients, which might provide novel perspective for understanding the crucial role of the amygdala in the neural mechanism of PE.

KEY POINTS

• As one of the most common diseases in men, PE may be related to abnormal brain mechanisms. • Functional and structural magnetic resonance imaging used to explore amygdala abnormalities in PE patients. • The correlation between clinical scores and functional connectivity was used to assess the reasonability of the results.

Basal ganglia lateralization in different types of reward

Reward processing is a fundamental human activity. The basal ganglia are recognized for their role in reward processes; however, specific roles of the different nuclei (e.g., nucleus accumbens, caudate, putamen and globus pallidus) remain unclear. Using quantitative meta-analyses we assessed whole-brain and basal ganglia specific contributions to money, erotic, and food reward processing. We analyzed data from 190 fMRI studies which reported stereotaxic coordinates of whole-brain, within-group results from healthy adult participants. Results showed concordance in overlapping and distinct cortical and sub-cortical brain regions as a function of reward type. Common to all reward types was concordance in basal ganglia nuclei, with distinct differences in hemispheric dominance and spatial extent in response to the different reward types. Food reward processing favored the right hemisphere; erotic rewards favored the right lateral globus pallidus and left caudate body. Money rewards engaged the basal ganglia bilaterally including its most anterior part, nucleus accumbens. We conclude by proposing a model of common reward processing in the basal ganglia and separate models for money, erotic, and food rewards.

Sex Differences in the Motivation for Viewing Sexually Arousing Images

Sexual motivation strongly influences mate choice and dating behavior and can be triggered by merely viewing sexually arousing visual images, such as erotic pictures and movies. Previous studies suggested that men, more than women, tend to search for sexual cues that signal promiscuity in short-term mates. However, it remains to be tested whether sex differences in the motivation to view sexual cues can be observed by using robust and well-controlled behavioral measures. To this end, we employed a pay-per-view key-pressing task. Japanese self-identified heterosexual male and female participants viewed images of men, women, or couples with two levels of sexual arousal (sexual vs. less sexual). Participants could alter the viewing time of a presented image according to their willingness to keep viewing it. Male participants were the most eager to view sexually arousing images of the opposite sex, whereas female participants were more strongly motivated to view less sexual images of couples. Such sex differences may reflect differentiated reproductive strategies between men and women in terms of men’s motivation toward promiscuity and women’s motivation toward long-term relationships.

Decoding Neural Representations of Affective Scenes in Retinotopic Visual Cortex

The perception of opportunities and threats in complex visual scenes represents one of the main functions of the human visual system. The underlying neurophysiology is often studied by having observers view pictures varying in affective content. It has been shown that viewing emotionally engaging, compared with neutral, pictures (1) heightens blood flow in limbic, frontoparietal, and anterior visual structures and (2) enhances the late positive event-related potential (LPP). The role of retinotopic visual cortex in this process has, however, been contentious, with competing theories predicting the presence versus absence of emotion-specific signals in retinotopic visual areas. Recording simultaneous electroencephalography-functional magnetic resonance imaging while observers viewed pleasant, unpleasant, and neutral affective pictures, and applying multivariate pattern analysis, we found that (1) unpleasant versus neutral and pleasant versus neutral decoding accuracy were well above chance level in retinotopic visual areas, (2) decoding accuracy in ventral visual cortex (VVC), but not in early or dorsal visual cortex, was correlated with LPP, and (3) effective connectivity from amygdala to VVC predicted unpleasant versus neutral decoding accuracy, whereas effective connectivity from ventral frontal cortex to VVC predicted pleasant versus neutral decoding accuracy. These results suggest that affective scenes evoke valence-specific neural representations in retinotopic visual cortex and that these representations are influenced by reentry signals from anterior brain regions.

Compulsive Internet Pornography Use and Mental Health: A Cross-Sectional Study in a Sample of University Students in the United States

Background

The sustained rise in negative mental health reports among university students is a source of continued global concern, and investigation continues into potential contributors to this rise. This includes the increased prevalence of risky sexual behaviors. Related is the increased prevalence of pornography use. Our study sought to explore the potential relationship between compulsive use of pornography and mental health in university students.

Methods

Our sample consisted of university students (N = 1031; 34% male, 66% female) from Franciscan University of Steubenville, Steubenville, Ohio. An anonymous survey was sent to all students at the university over the age of 18. The survey was comprised of the following: (1) demographic questions, (2) questions on pornography use and perception, (3) a modified version of the Compulsive Internet Use Scale (mCIUS) assessing various factors associated with compulsive internet pornography use, (4) questions assessing emotional and sexual states relative to pornography use (EmSS), and (5) the 21-question version of the Depression, Anxiety and Stress Scale (DASS-21).

Results

Our results indicate that 56.6% of those surveyed reported lifetime pornography use, with a significantly higher proportion of males than females reporting such use. The majority of students reported accessing pornography through internet-related technologies. Additionally, 17.0, 20.4, and 13.5% of students reported severe or extremely severe levels of depression, anxiety and stress, respectively, with compulsive pornography use significantly affecting all three mental health parameters in both sexes. Exploratory Factor Analysis identified three factors suggesting emotional coping, dependence and preoccupation for the mCIUS items and three factors reflecting interoceptive, impotent, and extrinsic characteristics for the EmSS items. Regression analysis indicated that various demographics, items pertaining to reduced control and social impairment, and other variables pertaining to pornography use predicted mental health outcomes. Faith, morals and personal motivation were the primary variables reported to help reduce pornography use.

Conclusion

Our analyses indicate a significant relationship between mental health and pornography use, including behaviors reflecting behavioral addictions, highlighting the necessity for a better understanding and consideration of the potential contribution of internet pornography to negative mental health among university students.

Case-by-case: Emotional stimulus significance and the modulation of the EPN and LPP

Stimuli encountered in the environment are continuously evaluated according to their affective stimulus significance. Numerous event-related potential studies have shown that the early posterior negativity (EPN) and the late positive potential (LPP) are larger for pictures high in emotional arousal compared to low arousing images. Here, we used a case-by-case approach to determine the emotional modulation of the EPN and LPP at the level of the individual case. We probed the effect in three studies regarding behavior systems of predator fear, disease avoidance, and sexual reproduction. In each study, high and low arousing pictures from the respective behavior system were presented and event-related brain potentials measured. At the group level, previous findings regarding an enhanced EPN and LPP for high compared to low arousing stimuli were replicated. Novel findings were observed when analyzing each case individually. The majority of participants showed significantly larger EPN and LPP amplitudes to pictures showing threatening compared to harmless animals (15 and 16 out of 16 tests, respectively), images of disease and mutilation compared to neutral people (15 and 17 out of 18 tests, respectively), and high-arousing erotic compared to romantic pictures (17 and 17 out of 17 tests, respectively). Further analyses exploring the tradeoff between specificity and sensitivity suggest reliance on picture categories of sexual reproduction and disease avoidance. Overall, the present findings demonstrate that the case-by-case approach can be useful for revealing a general principle of emotional stimulus processing common-to-all. Implications for the reproducibility of the findings and biomarker development are discussed.

Periodontitis, erectile dysfunction, reproductive hormones, and semen quality: A systematic review

BACKGROUND

There is increasing evidence that periodontitis may affect male sexual health (MSH) (erectile function, production of sex hormones, and semen quality). However, a limited number of clinical studies demonstrate the association between MSH and periodontitis.

OBJECTIVES

The aim of this study was to explore the relationship between periodontitis and MSF.

MATERIALS AND METHODS

A comprehensive systematic review of the published literature in MEDLINE, PubMed, Scopus, Cochrane, EMBASE, and Web of Science databases from the earliest available online indexing year until October 2020 was performed, in accordance with the PRISMA guidelines. Keywords related to periodontitis were combined with words describing MSH.

RESULT

A total of 19 studies were included and discussed in the systematic review. The number of study participants ranged from 53 to 197,136 individuals, aged between 18 and 95 years (mean age, 41.2 years). Six studies did not report the age of the participants. Out of nine studies, eight found a significant association between erectile dysfunction (ED) and periodontitis. Only three studies evaluated the association between sex hormone levels and periodontitis, and two of these studies showed that patients with periodontitis are expected to exhibit higher levels of testosterone. Finally, out of five studies, two demonstrated a significant association between semen quality and periodontitis.

DISCUSSION

The findings in this review were limited by the quality and the few available studies. Results from the observational studies might have been affected by recall bias and confounded by cofactors.

CONCLUSION

The results of this systematic review revealed a significant association between periodontitis and ED, although the responsible mechanisms remain unclear. The potential associations between sex hormone levels, semen quality, and periodontitis are yet to be demonstrated. In order to improve patient management, dentists and physicians need to be aware of the association between male sexual health problems and periodontitis.

The Erogenous Mirror: Intersubjective and Multisensory Maps of Sexual Arousal in Men and Women

Erogenous zones of the body are sexually arousing when touched. Previous investigations of erogenous zones were restricted to the effects of touch on one's own body. However, sexual interactions do not just involve being touched, but also involve touching a partner and mutually looking at each other's bodies. We take a novel interpersonal approach to characterize the self-reported intensity and distribution of erogenous zones in two modalities: touch and vision. A large internet sample of 613 participants (407 women) completed a questionnaire, where they rated intensity of sexual arousal related to different body parts, both on one's own body and on an imagined partner's body in response to being touched but also being looked at. We report the presence of a multimodal erogenous mirror between sexual partners, as we observed clear correspondences in topographic distributions of self-reported arousal between individuals' own bodies and their preferences for a partner's body, as well as between those elicited by imagined touch and vision. The erogenous body is therefore organized and represented in an interpersonal and multisensory way.

Retrospective Evaluation of Sequential Events and the Influence of Preference-Dependent Working Memory: A Computational Examination

Humans organize sequences of events into a single overall experience, and evaluate the aggregated experience as a whole, such as a generally pleasant dinner, movie, or trip. However, such evaluations are potentially computationally taxing, and so our brains must employ heuristics (i.e., approximations). For example, the peak-end rule hypothesis suggests that we average the peaks and end of a sequential event vs. integrating every moment. However, there is no general model to test viable hypotheses quantitatively. Here, we propose a general model and test among multiple specific ones, while also examining the role of working memory. The models were tested with a novel picture-rating task. We first compared averaging across entire sequences vs. the peak-end heuristic. Correlation tests indicated that averaging prevailed, with peak and end both still having significant prediction power. Given this, we developed generalized order-dependent and relative-preference-dependent models to subsume averaging, peak and end. The combined model improved the prediction power. However, based on limitations of relative-preference-including imposing a potentially arbitrary ranking among preferences-we introduced an absolute-preference-dependent model, which successfully explained the remembered utilities. Yet, because using all experiences in a sequence requires too much memory as real-world settings scale, we then tested "windowed" models, i.e., evaluation within a specified window. The windowed (absolute) preference-dependent (WP) model explained the empirical data with long sequences better than without windowing. However, because fixed-windowed models harbor their own limitations-including an inability to capture peak-event influences beyond a fixed window-we then developed discounting models. With (absolute) preference-dependence added to the discounting rate, the results showed that the discounting model reflected the actual working memory of the participants, and that the preference-dependent discounting (PD) model described different features from the WP model. Taken together, we propose a combined WP-PD model as a means by which people evaluate experiences, suggesting preference-dependent working-memory as a significant factor underlying our evaluations.

Pubertal timing predicts adult psychosexuality: Evidence from typically developing adults and adults with isolated GnRH deficiency

Evidence suggests that psychosexuality in humans is modulated by both organizational effects of prenatal and peripubertal sex steroid hormones, and by activational effects of circulating hormones in adulthood. Experimental work in male rodents indicates that sensitivity to androgen-driven organization of sexual motivation decreases across the pubertal window, such that earlier puberty leads to greater sex-typicality. We test this hypothesis in typically developing men (n = 231) and women (n = 648), and in men (n = 72) and women (n = 32) with isolated GnRH deficiency (IGD), in whom the precise timing of peripubertal hormone exposure can be ascertained via the age at which hormone replacement therapy (HRT) was initiated. Psychosexuality was measured with the Sexual Desire Inventory-2 (SDI-2) and Sociosexual Orientation Inventory-Revised (SOI-R). In both sexes, earlier recalled absolute pubertal timing predicted higher psychosexuality in adulthood, although the magnitude of these associations varied with psychosexuality type and group (i.e., typically developing and IGD). Results were robust when controlling for circulating steroid hormones in typically developing participants. Age of initiation of HRT in men with IGD negatively predicted SOI-R. We discuss the clinical implications of our findings for conditions in which pubertal timing is medically altered.

Anatomic alterations across amygdala subnuclei in medication-free patients with obsessive-compulsive disorder

BACKGROUND

The amygdala has been implicated in obsessive-compulsive disorder (OCD), a common, disabling illness. However, the regional distribution of anatomic alterations in this structure and their association with the symptoms of OCD remains to be established.

METHODS

We collected high-resolution 3D T1-weighted images from 81 untreated patients with OCD and no lifetime history of comorbid psychotic, affective or anxiety disorders, and from 95 age- and sex-matched healthy controls. We extracted the volume of the central nucleus of the amygdala (CeA) and the basolateral complex of the amygdala (BLA) and compared them across groups using FreeSurfer 6.0. In exploratory analyses, we evaluated other subnuclei, including the cortical medial nuclei, the anterior amygdaloid area, and the corticoamygdaloid transition area.

RESULTS

Patients with OCD had reduced amygdala volume bilaterally compared with healthy controls (left, p = 0.034; right, p = 0.002). Volume reductions were greater in the CeA (left: -11.9%, p = 0.002; right: -13.3%, p < 0.001) than in the BLA (left lateral nucleus: -3.3%, p = 0.029; right lateral nucleus: -3.9%, p = 0.018; right basal nucleus: -4.1%, p = 0.017; left accessory basal nucleus: -6.5%, p = 0.001; right accessory basal nucleus: -9.3%, p < 0.001). Volume reductions in the CeA were associated with illness duration. Exploratory analysis revealed smaller medial (left: -15.4%, p < 0.001, η2 = 0.101) and cortical (left: -9.1%, p = 0.001, η2 = 0.058; right: -15.4%, p < 0.001, η2 = 0.175) nuclei in patients with OCD compared with healthy controls.

LIMITATIONS

Although the strict exclusion criteria used in the study helped us to identify OCD-specific alterations, they may have limited generalizability to the broader OCD population.

CONCLUSION

Our results provide a comprehensive anatomic profile of alterations in the amygdala subnuclei in untreated patients with OCD and highlight a distinctive pattern of volume reductions across subnuclei in OCD. Based on the functional properties of the amygdala subnuclei established from preclinical research, CeA impairment may contribute to behavioural inflexibility, and BLA disruption may be responsible for altered fear conditioning and the affective components of OCD.

I'll Show You Mine so You'll Show Me Yours: Motivations and Personality Variables in Photographic Exhibitionism

Given that the sharing of genital images - colloquially known as "dick pics" - has become a widespread phenomenon, the purpose of the present study was to explore men's motivations for sending unsolicited images of their genitalia. A secondary purpose was to investigate the personality and sexuality characteristics of men who send dick pics relative to those who do not. 1,087 men completed an online survey, which included a demographic questionnaire and measures of narcissism, exhibitionism, erotophilia-erotophobia, and sexism. Also included was a measure developed specifically for the current study exploring the motivations behind sending unsolicited genital pictures as well as reactions senders hoped to elicit from their recipients. We determined that the most frequently reported motivational category for sending genital images was a transactional mindset (i.e., motivated by hopes of receiving images in return), while the most commonly desired reaction from recipients was that of sexual excitement. Further, we determined that men who reported having sent unsolicited dick pics demonstrated higher levels of narcissism and endorsed greater ambivalent and hostile sexism than their non-sending counterparts. This study is among the first to provide empirical evidence into the motivations and personality characteristics of men who send unsolicited dick pics.

Different Neural Correlates of Sexually Preferred and Sexually Nonpreferred Stimuli

BACKGROUND

The differences and relationships between stimulus-related brain activation for sexually preferred stimuli and sexually nonpreferred stimuli are still unclear.

AIM

This study aimed to identify brain regions that were mostly associated with sexual stimuli.

METHODS

We used the activation likelihood estimation, meta-analytic connectivity modelling, and behavioral domain metadata in the BrainMap database to perform this analysis.

OUTCOMES

We found convergent activation foci and created a model for the extended brain network involved in responses to sexual stimuli and also assessed the functional properties of these regions.

RESULTS

A total of 34 experiments from 15 studies including 368 subjects and 343 foci were analyzed. The results showed that sexual stimuli are related to the extensive activation of the occipital-temporal-limbic system and less extensive activation of the basal ganglia. Sexually preferred stimuli activated mainly the anterior cingulate cortex and right fusiform gyrus, while sexually nonpreferred stimuli activated the limbic system, occipital gyrus, and thalamus.

CLINICAL IMPLICATIONS

To have a further understanding of the central mechanisms of human sexuality.

STRENGTHS & LIMITATIONS

Patient characteristics and analysis techniques in the included studies were heterogeneous.

CONCLUSIONS

These findings suggest that the anterior cingulate cortex is an important cognitive control area for both sexually preferred and nonpreferred stimuli. Meta-analytic connectivity modelling analysis revealed a network of the core brain areas involved in response to sexual stimuli, and behavioral domain analysis indicated that these areas have both common and discrete functional properties. Long X, Tian F, Zhou Y, et al. Different Neural Correlates of Sexually Preferred and Sexually Nonpreferred Stimuli. J Sex Med 2020;17:1254-1267.

Response inhibition during processing of sexual stimuli in males with problematic hypersexual behavior

BACKGROUND AND AIMS

Individuals with problematic hypersexual behavior (PHB) are unable to control their sexual cravings, regardless of other situational factors. This inability to control cravings is a common trait in patients with neurological pathologies related to response inhibition. Until recently, however, it was unclear whether individuals with PHB have decreased inhibition and altered neural responses in the brain regions associated with inhibition compared to healthy control individuals, especially in the presence of distracting sexual stimuli. In this study, we examined the neural and psychological underpinnings of inhibition in individuals with PHB.

METHODS

Thirty individuals with PHB and 30 healthy subjects underwent functional magnetic resonance imaging while performing a modified go/no-go task with neutral or sexual backgrounds used as distractors.

RESULTS

Individuals with PHB showed poorer response inhibition than healthy subjects, especially when sexual distractors were present. Further, compared to healthy control subjects, individuals with PHB showed decreased activation in the right inferior frontal gyrus (IFG) and reduced functional connectivity between the IFG and the pre-supplementary motor area (preSMA) when response inhibition was required. Finally, the reduced activation and connectivity were more pronounced in the presence of sexual distractors than in the presence of neutral distractors.

DISCUSSION

These findings suggest that individuals with PHB show reduced ability to inhibit responses that might be related to lower IFG activation and IFG-preSMA connectivity during response inhibition. Our results provide insights into the neurobiological underpinnings of poor response inhibition in individuals with PHB.

Interactive effects of gender and sexual orientation on cortical thickness, surface area and gray matter volume: a structural brain MRI study

Background

Testosterone is thought to play a crucial role in sexual differentiation of the brain, and sexual orientation is programmed into our brain structures even when we are still fetuses. Although gender and sexual orientation differences have been shown respectively in many brain structures, the mechanism underlying the sexual differentiation of the brain is still unknown. The study is to investigate the interactive effects of gender and sexual orientation on cerebral structures in homosexual and heterosexual people.

Methods

Sexual orientation was evaluated by the Kinsey scale. We collected structural magnetic resonance image (MRI) data of local cortical thickness, surface area, and gray matter volume in all the subjects (29 homosexual and 29 heterosexual men, 17 homosexual and 17 heterosexual women). Statistical maps were generated using a general linear model (GLM) using FreeSurfer's Query, Design, Estimate, Contrast (QDEC) interface. We had sexual orientation and gender as 2 discrete factors with 2 levels, allowing for the generation of the interaction between sexual orientation and gender: homosexual women and heterosexual men versus heterosexual women and homosexual men. Coordinates were in Talairach space. All the cluster sizes were calculated with a P value of 0.01.

Results

Results revealed interactions concerning the area and gray matter volume between the factors of sexual orientation and gender. Regarding the thickness, an interaction was not found in any regions of the clusters. Regarding the area, an interaction was found in region of left middle temporal lobe, inferior temporal lobe, lateral occipital lobe, fusiform [(-58.1, -38.6, -14.7), maximum vertex-wise (MV) log₁₀(P) =3.30, cluster size (CS) =1,286.90 mm²], and left rostral middle frontal lobe, pars opercularis, caudal middle frontal lobe [(-37.3, 23.6, 24.8), MV log₁₀(P) =2.92, CS =1,194.40 mm²]. Regarding the gray matter volume, an interaction was found in the region of the left pars opercularis (inferior frontal gyrus) [(-42.9, 6.3, 18.5), MV log₁₀(P) =1.31, CS =526.79 mm²].

Conclusions

The present study extends our understandings of how structural features differ in homosexual men, heterosexual men, homosexual women, and heterosexual women. Furthermore, it highlights the interactions between sexual orientation and gender in the left inferior frontal gyrus, bilateral temporal lobe, and the right rostral anterior cingulate cortex, which are suggested to play a critical role in the sexual differentiation of the human brain.

Neural Responses to Sexual Stimuli in Heterosexual and Homosexual Men and Women: Men's Responses Are More Specific

Patterns of genital arousal in response to gendered sexual stimuli (i.e., sexual stimuli presenting members of only one sex at a time) are more predictive of men's than of women's sexual orientations. Additional lines of evidence may shed light on the nature of these differences. We measured neural activation in homosexual and heterosexual men and women using fMRI while they viewed three kinds of gendered sexual stimuli: pictures of nude individuals, pictures of same-sex couples interacting, and videos of individuals self-stimulating. The primary neural region of interest was the ventral striatum (VS), an area of central importance for reward processing. For all three kinds of stimuli and for both VS activation and self-report, men's responses were more closely related to their sexual orientations compared with women's. Furthermore, men showed a much greater tendency to respond more positively to stimuli featuring one sex than to stimuli featuring the other sex, leading to higher correlations among men's responses as well as higher correlations between men's responses and their sexual orientations. Whole-brain analyses identified several other regions showing a similar pattern to the VS, and none showed an opposite pattern. Because fMRI is measured identically in men and women, our results provide the most direct evidence to date that men's sexual arousal patterns are more gender specific than women's.

Becoming sexy: Contrapposto pose increases attractiveness ratings and modulates observers' brain activity

Previous neurophysiological studies have revealed the neural correlates of human body form perception, as well as those related to the perception of attractive body sizes. In the current study we aimed to extend the neurophysiological studies regarding body perception by investigating the perception of human body posture to provide insights into the cognitive mechanisms responsive to bodily form, and the processing of its attractiveness. To achieve these aims, we used the contrapposto posture which creates an exaggeration of low waist to hip ratio (WHR), an indicator of women's attractiveness. Electroencephalogram (EEG) signals were recorded while participants completed both (i) an oddball task presenting female body forms differing in pose (contrapposto vs. standing) and viewing angle (anterior vs. posterior), and (ii) a subsequent active attractiveness judgement task. Behavioral results showed that a contrapposto pose is considered more attractive than a neutral standing pose. Results at the neural level showed that body posture modulates the visual information processing in early ERP components, indicating attentional variations depending on human body posture; as well as in late components, indicating further differences in attention and attractiveness judgement of stimuli varying in body pose. Furthermore, the LORETA results identified the middle temporal gyrus as well as angular gyrus as the key brain regions activated in association with the perception and attractiveness judgment of females' bodies with different body poses. Overall, the current paper suggests the evolutionary adaptive preference for lower WHRs as in the contrapposto pose activating brain regions associated with visual perception and attractiveness judgement.

Neuroanatomy and function of human sexual behavior: A neglected or unknown issue?

INTRODUCTION

Sexual desire, arousal, and orgasm are mediated by complex, yet still not fully understood, interactions of the somatic and autonomic nervous systems operating at the central and peripheral levels. Disruption of endocrine, neural, or vascular response, caused by aging, medical illness, neurological diseases, surgery, or drugs, can lead to sexual dysfunctions, thus significantly affecting patients' quality of life.

PURPOSE

This narrative review aims at characterizing the involvement of the central nervous system in human sexual behavior.

METHODS

A literature search was conducted using PubMed in its entirety up to June 2018, analyzing the studies dealing with the neurobiological and neurophysiological basis of human sexuality.

RESULTS

Sexual behavior is regulated by both subcortical structures, such as the hypothalamus, brainstem, and spinal cord, and several cortical brain areas acting as an orchestra to finely adjust this primitive, complex, and versatile behavior. At the central level, dopaminergic and serotonergic systems appear to play a significant role in various factors of sexual response, although adrenergic, cholinergic, and other neuropeptide transmitter systems may contribute as well.

CONCLUSIONS

Providing healthcare professionals with information concerning sexual behavior may overcome useless and sometimes dangerous barriers and improve patient management, since sexual well-being is considered one of the most important aspects of one's quality of life.

Sex differences in main olfactory system pathways involved in psychosexual function

We summarize literature from animal and human studies assessing sex differences in the ability of the main olfactory system to detect and process sex-specific olfactory signals ("pheromones") that control the expression of psychosexual functions in males and females. A case is made in non primate mammals for an obligatory role of pheromonal signaling via the main olfactory system (in addition to the vomeronasal-accessory olfactory system) in mate recognition and sexual arousal, with male-specific as well as female-specific pheromones subserving these functions in the opposite sex. Although the case for an obligatory role of pheromones in mate recognition and mating among old world primates, including humans, is weaker, we review the current literature assessing the role of putative human pheromones (eg, AND, EST, "copulin"), detected by the main olfactory system, in promoting mate choice and mating in men and women. Based on animal studies, we hypothesize that sexually dimorphic effects of putative human pheromones are mediated via main olfactory inputs to the medial amygdala which, in turn, transmits olfactory information to sites in the hypothalamus that regulate reproduction.

Non-food rewards and highly processed food intake in everyday life

Reducing intake of highly processed, energy-dense food may prevent chronic disease. One proposed intervention strategy for reducing intake of these foods is to increase non-food reward experiences (e.g., music, socializing, art) in their place. However, research supporting this strategy has yet to establish temporal order between non-food reward experiences and highly processed food intake, and has yet to test mediators. The current study sought to build upon this literature with an ambulatory electronic diary study wherein the time-specific associations between non-food reward experiences and highly processed food intake were observed. A sample of 84 young adults reported on multiple types of non-food reward experiences and highly processed food intake hourly for two weekdays and two weekend days through an application on their personal electronic devices. Time-lagged analysis was employed to predict the odds of highly processed food intake in the following hour from non-food rewards experienced in the current hour. Secondary (e.g., receiving positive social feedback) and hedonic (e.g., viewing pleasant images) non-food reward experiences in the current hour predicted greater instead of lower odds of highly processed food intake in the following hour. These associations were mediated by increased subjective pleasure. Purely eudaimonic (e.g., affirming values), social (e.g., cooperating with others), and primary (e.g., having sex) reward experiences generally did not predict odds of highly processed food intake in the following hour. These results suggest that-at least for young adults-many non-food reward experiences may fail to reduce highly processed food intake, and some may even backfire. A different intervention strategy targeting reward processes implicated in highly processed food intake (e.g., interfering with conditioned learned associations) may prove a more promising avenue for improving physical health.

Age and Gender Differences in Emotion Recognition

Background

Existing literature suggests that age affects recognition of affective facial expressions. Eye-tracking studies highlighted that age-related differences in recognition of emotions could be explained by different face exploration patterns due to attentional impairment. Gender also seems to play a role in recognition of emotions. Unfortunately, little is known about the differences in emotion perception abilities across lifespans for men and women, even if females show more ability from infancy.

Objective

The present study aimed to examine the role of age and gender on facial emotion recognition in relation to neuropsychological functions and face exploration strategies. We also aimed to explore the associations between emotion recognition and quality of life.

Methods

60 healthy people were consecutively enrolled in the study and divided into two groups: Younger Adults and Older Adults. Participants were assessed for: emotion recognition, attention abilities, frontal functioning, memory functioning and quality of life satisfaction. During the execution of the emotion recognition test using the Pictures of Facial Affects (PoFA) and a modified version of PoFA (M-PoFA), subject’s eye movements were recorded with an Eye Tracker.

Results

Significant differences between younger and older adults were detected for fear recognition when adjusted for cognitive functioning and eye-gaze fixations characteristics. Adjusted means of fear recognition were significantly higher in the younger group than in the older group. With regard to gender’s effects, old females recognized identical pairs of emotions better than old males. Considering the Satisfaction Profile (SAT-P) we detected negative correlations between some dimensions (Physical functioning, Sleep/feeding/free time) and emotion recognition (i.e., sadness, and disgust).

Conclusion

The current study provided novel insights into the specific mechanisms that may explain differences in emotion recognition, examining how age and gender differences can be outlined by cognitive functioning and face exploration strategies.

Preference-based serial decisions are counterintuitively influenced by emotion regulation and conscientiousness

Our decisions have a temporally distributed order, and different choice orders (e.g., choosing preferred items first or last) can lead to vastly different experiences. We previously found two dominant strategies (favorite-first and favorite-last) in a preference-based serial choice setting (the 'sushi problem'). However, it remains unclear why these two opposite behavioral patterns arise: i.e., the mechanisms underlying them. Here we developed a novel serial-choice task, using pictures based on attractiveness, to test for a possible shared mechanism with delay discounting, the 'peak-end' bias (i.e., preference for experienced sequences that end well), or working-memory capacity. We also collected psychological and clinical metric data on personality, depression, anxiety, and emotion regulation. We again found the two dominant selection strategies. However, the results of the delay, peak-end bias, and memory capacity tasks were not related to serial choice, while two key psychological metrics were: emotion regulation and conscientiousness (with agreeableness also marginally related). Favorite-first strategists actually regulated emotions better, suggesting better tolerance of negative outcomes. Whereas participants with more varied strategies across trials were more conscientious (and perhaps agreeable), suggesting that they were less willing to settle for a single, simpler strategy. Our findings clarify mechanisms underlying serial choice and show that it may reflect a unique ability to organize choices into sequences of events.