The time course of implicit processing of erotic pictures: An event-related potential study

Automatic attention to sexual stimuli: exploring the role of neuroticism and sexual excitation/inhibition through event-related potentials

BACKGROUND

Previous findings have shown that neuroticism is a higher-order vulnerability factor in the development and maintenance of sexual dysfunctions and can have an impact on the attentional processing of sexual stimuli; however, the influence of psychosexual dimensions on the early automatic phases of such cognitive processes has not been established yet.

AIM

To examine the mediating role of sexual inhibition/excitation propensity in the relationship between neuroticism and automatic attention to visual erotica and to identify the neuroelectric correlates of such a process.

METHODS

We analyzed the answers provided by 58 individuals on the Neuroticism subscale of the NEO Personality Inventory-Revised and the Sexual Inhibition/Excitation Scales. Event-related potentials (ERPs) were recorded during a modified oddball paradigm containing romantic and sexually explicit pictures. Parallel mediations were performed to simultaneously test the mediating role of sexual inhibition/excitation in the relationship between neuroticism and each ERP.

OUTCOMES

Three early attention ERP components (P1, P2, and N2) were assessed.

RESULTS

Findings revealed an indirect effect of neuroticism on automatic attention, via sexual inhibition due to threat of performance failure (SIS1), for romantic and sexually explicit stimuli. This effect was significant only for component N2, which showed increased amplitudes and earlier latencies in participants with high SIS1.

CLINICAL IMPLICATIONS

Sexual stimuli, due to their emotional valence and arousal potential, might be perceived as virtually threatening by individuals with neuroticism, who may benefit from strategies that decrease hyperarousal and sympathetic activation.

STRENGTHS AND LIMITATIONS

This was one of the first studies to analyze neuroelectric activity associated with automatic attention toward sexual stimuli in relation to personality and sexual excitation/inhibition propensity. Nevertheless, the limited number of participants demands caution in generalizing the results.

CONCLUSION

These results provide a better understanding of the relationship between personality and sexual cognition and open new avenues of research in relation to other automatic cognitive phenomena related to human sexual behavior.

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.

Exogenous Attention to Emotional Stimuli Presenting Realistic (3D) Looming Motion

Previous research shows that dynamic stimuli, on the one hand, and emotional stimuli, on the other, capture exogenous attention due to their biological relevance. Through neural (ERPs) and behavioral measures (reaction times and errors), the present study explored the combined effect of looming motion and emotional content on attentional capture. To this end, 3D-recreated static and dynamic animals assessed as emotional (positive or negative) or neutral were presented as distractors while 71 volunteers performed a line orientation task. We observed a two-phase effect: firstly (before 300 ms), early components of ERPs (P1p and N2po) showed enhanced exogenous attentional capture by looming positive distractors and static threatening animals. Thereafter, dynamic and static threatening distractors received enhanced endogenous attention as revealed by both late ERP activity (LPC) and behavioral (errors) responses. These effects are likely explained by both the emotional valence and the distance of the stimulus at each moment.

Automaticity of Early Sexual Attention: An Event-Related Potential Study

A promising line of research on forensic assessment of paraphilic sexual interest focuses on behavioral measures of visual attention using sexual stimuli as distractors. The present study combined event-related potentials (ERPs) with behavioral measures to investigate whether detection of a hidden sexual preference can be improved with ERPs. Normal variants of sexual orientation were used for a proof-of-concept investigation. Accordingly, 40 heterosexual and 40 gay men participated in the study. Within each group, half of the participants were instructed to hide their sexual orientation. The results showed that a match between sexual orientation and stimulus delays responses and influences ERP before motor responses. Late ERP components showed higher potential in differentiating hidden sexual preferences than motor responses, thereby showing how ERPs can be used in combination with reaction time measures to potentially facilitate the detection of hidden sexual preferences.

Temporal dynamics of explicit and implicit moral evaluations

Explicit moral evaluation is often accompanied with active attention and explicit responses to moral information, while implicit moral evaluation happens in passive attention and implicit response to moral information. Previous studies have pointed out the differences in the neural mechanisms underlying explicit and implicit moral processing on the spatial dimension, however, the temporal differences between these two processes have not been clear. This study aimed at comparing the temporal dynamics between explicit and implicit moral evaluation of harm/care-related moral scenarios with high/low emotional arousal by using event-related potentials (ERP) technique. The behavioral results showed that the accuracy of the explicit task is higher than that of the implicit task, especially for high-arousal moral actions. The ERP results mainly revealed that regardless of the task type, the brain responses to moral evaluations can be divided into early emotional arousal processing indexed by the frontal N1, moral intuition indexed by the frontal N2, and middle/late stages of processing integration of emotional arousal and moral cognition which involve elaborative processing and cognitive control, reflected by the frontal P2, parietal P3, parietal LPP, and FSW. Moreover, explicit and implicit moral evaluations mainly differed in the late stage of moral processing indexed by the P3, LPP and FSW. Our findings provide robust evidence for the "hybrid" model supposed by Huebner, which suggested that both explicit and implicit moral evaluations involved a complex interaction between emotional processes and moral cognition, and the later ERP results strongly supported that explicit and implicit moral evaluations represented two relatively independent processes, fitting the multinomial model supposed by Cameron.

Attention Bias and Recognition of Sexual Images in Depression

Depression greatly affects sexuality. Theoretical and empirical evidence account for the existence of attention bias to sex-related stimuli. This attention bias might be impaired in depression, resulting in sexual problems. A sample of 13 patients with depression and 13 matched healthy controls were tested using the dot-probe and picture recognition task to measure attention to erotic images. No difference in attention to sex-related stimuli (ω² = 0, p = 0.22) and in memory bias (ω² = 0, p = 0.72) was found between the two groups. Explorative analyses were conducted to identify the sexual content-induced delay effect in the data, assess variability differences, and compare trial-level bias score-based indexes between groups. Across all analyses, there was little evidence for depression affecting sexual-related cognitive processing, and even this might be explained by other means. Our results suggest that restrained attention is probably not the main factor behind sexual problems in depression.

Neuroticism and Attention Toward Sexual and Non-Sexual Images During an Oddball Task: Evidence from Event-Related Potentials

While previous research has argued that neuroticism is a vulnerability factor for the experience of sexual difficulties, the basic cognitive processes associated with the impact of such a personality trait on the processing of sexually explicit stimuli are less understood. The current study examined the influence of neuroticism on the attentional processes and its neurophysiological correlates during the perception of sexual and non-sexual images. Event-related potentials from 30 women and 28 men were recorded during a modified oddball paradigm in which participants of both sexes visualized stimuli from three different categories (sexual, non-sexual positive, and non-sexual negative), and two arousal levels (high and low arousal). A P1 latency effect was found for female participants, in which high neuroticism was associated with longer latencies for pornographic compared to romantic sexual images. Higher levels of neuroticism were also associated with higher P3 amplitudes for highly arousing images, with both sexual and non-sexual content. Results were interpreted in light of the information processing model of sexual arousal and showed that neuroticism seems to impact both automatic and conscious pathways of processing of sexual stimuli.

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.

The Effects of Aversive Mood State on the Affective Anticipation and Perception: An Event-Related Potential Study

Deficits in the anticipation and experience of affective events represent a key risky factor for a variety of mental disorders, such as anxiety and depression. Here, we examined temporal dynamics underlying the modulations of the aversive mood state on neural responses of anticipating and perceiving affective pictures. Participants were asked to perform an affective cueing paradigm in both threat and safe contexts. In the task, a cue (S1) signaled the subsequent presentation of positive/negative event (e.g., happy or fearful faces) as an affective target stimulus (S2), and participants were instructed to indicate their subjective feelings in response to the target stimuli while electroencephalography (EEG) was recording. Our findings revealed that threat context compared with the safe context attenuated the contingent negative variation (CNV) responses to the cues of positive expressions, and decreased differential late positive potential (LPP) responses to the perception of negative and positive events. These findings suggest that aversive mood dampens the anticipation of positive events and inhibits the elaboration of negative events. The current findings do not only advance our understanding on the temporal characteristics of affective anticipation and experience but also have implications on the emotional deficits across various mental disorders characterized by chronic mood disturbances.

The Sexualization–Objectification Link: Sexualization Affects the Way People See and Feel Toward Others

Recent research has examined the sexualization–objectification link (i.e., whether sexualized individuals are appraised as if they were objects rather than persons). This research has found that sexualized individuals are more likely to be processed and categorized as if they were objects and are also perceived as possessing fewer humanlike traits than nonsexualized individuals. In addition, sexualization prompts negative behaviors such as social exclusion. Altogether, these findings shed light on mechanisms that might underlie violence toward sexualized individuals.

Embodiment and Humiliation Moderation of Neural Responses to Others' Suffering in Female Submissive BDSM Practitioners

Giving and receiving pain are common in the practice of BDSM (bondage-discipline, dominance-submission, and sadism-masochism). Playing a submissive role during BDSM practice weakens both the behavioral and neural empathic responses of female individuals to others' suffering, suggesting that long-term BDSM experience affects BDSM practitioners' empathic ability. This study further investigates whether physical restriction during BDSM practice also modulates individuals' neural responses to others' suffering. We measured neural responses to others' suffering by recording event-related potentials (ERPs) in female submissives while they viewed painful and neutral expressions in sexual sadistic/general social contexts under ball gag Blocking and Relaxed conditions. The neural responses recorded during 92-112 ms (N1), 132-172 ms (P2), 200-340 ms (N2), early late positive potential (LPP, 400-600 ms), and late LPP (700-1,000 ms) were included in the analyses. Compared to the relaxed condition, when a ball gag was used to prevent facial muscle movement and facial mimicry, the N1, early LPP, and late LPP responses neural responses to others' suffering were inhibited. The moderation effect of ball gag blocking on the N1 and early LPP amplitudes was positively correlated with the subjective feelings of facial muscle stillness, and the blocking moderation effect on the late LPP amplitudes was positively correlated with subjective feelings of humiliation. This study is the first neuropsychological investigation of the transient BDSM-related physical restriction effects on BDSM practitioners. These findings suggest that physical restriction (via a ball gag) during BDSM practices increases the wearer's facial muscle stillness and sense of humiliation. This physical restriction inhibits both early automatic responses and late controlled processes in response to the suffering of others.

Revealing Clothing Does Not Make the Object: ERP Evidences That Cognitive Objectification is Driven by Posture Suggestiveness, Not by Revealing Clothing

Recent research found that sexualized bodies are visually processed similarly to objects. This article examines the effects of skin-to-clothing ratio and posture suggestiveness on cognitive objectification. Participants were presented images of upright versus inverted bodies while we recorded the N170. We used the N170 amplitude inversion effect (larger N170 amplitudes for inverted vs. upright stimuli) to assess cognitive objectification, with no N170 inversion effect indicating less configural processing and more cognitive objectification. Contrary to Hypothesis 1, skin-to-clothing ratio was not associated with cognitive objectification (Experiments 1-3). However, consistent with Hypothesis 2, we found that posture suggestiveness was the key driver of cognitive objectification (Experiment 2), even after controlling for body asymmetry (Experiment 3). This article showed that high (vs. low) posture suggestiveness caused cognitive objectification (regardless of body asymmetry), whereas high (vs. low) skin-to-clothing ratio did not. The implications for objectification and body perception literatures are discussed.

Magnocellular Bias in Exogenous Attention to Biologically Salient Stimuli as Revealed by Manipulating Their Luminosity and Color

Exogenous attention is a set of mechanisms that allow us to detect and reorient toward salient events—such as appetitive or aversive—that appear out of the current focus of attention. The nature of these mechanisms, particularly the involvement of the parvocellular and magnocellular visual processing systems, was explored. Thirty-four participants performed a demanding digit categorization task while salient (spiders or S) and neutral (wheels or W) stimuli were presented as distractors under two figure–ground formats: heterochromatic/isoluminant (exclusively processed by the parvocellular system, Par trials) and isochromatic/heteroluminant (preferentially processed by the magnocellular system, Mag trials). This resulted in four conditions: SPar, SMag, WPar, and WMag. Behavioral (RTs and error rates in the task) and electrophysiological (ERPs) indices of exogenous attention were analyzed. Behavior showed greater attentional capture by SMag than by SPar distractors and enhanced modulation of SMag capture as fear of spiders reported by participants increased. ERPs reflected a sequence from magnocellular dominant (P1p, ≃120 msec) to both magnocellular and parvocellular processing (N2p and P2a, ≃200 msec). Importantly, amplitudes in one N2p subcomponent were greater to SMag than to SPar and WMag distractors, indicating greater magnocellular sensitivity to saliency. Taking together, results support a magnocellular bias in exogenous attention toward distractors of any nature during initial processing, a bias that remains in later stages when biologically salient distractors are present.

The Neural Correlates of Cognitive Objectification

At an early stage of visual processing, human faces and bodies are typically associated with larger N170s when presented in an inverted (vs. upright) position, indexing the involvement of configural processing. We challenged this view and hypothesized that sexualized bodies would not be sensitive to inversion, thereby suggesting that they would be processed similarly to objects. Participants saw sexualized male and female bodies, nonsexualized male and female bodies, as well as objects in both upright and inverted positions while we recorded the N170. Results indicated that inverted (vs. upright) nonsexualized male and female bodies were associated with larger N170 amplitudes. In contrast, no N170 amplitude inversion effect emerged for sexualized male and female bodies or objects. These results suggest that sexualized bodies are processed similarly to objects and quite differently than nonsexualized bodies. We discuss the results and their implications in the light of the literatures in person perception and objectification.

The influence of affective state on exogenous attention to emotional distractors: behavioral and electrophysiological correlates

The interplay between exogenous attention to emotional distractors and the baseline affective state has not been well established yet. The present study aimed to explore this issue through behavioral measures and event-related potentials (ERPs). Participants (N = 30) completed a digit categorization task depicted over negative, positive or neutral distractor background pictures, while they experienced negative, positive and neutral affective states elicited by movie scenes. Behavioral results showed higher error rates and longer reaction times for negative distractors than for neutral and positive ones, irrespective of the current emotional state. Neural indices showed that the participants' affective state modulated N1 amplitudes, irrespective of distractor type, while the emotional charge of distractors modulated N2, irrespective of the emotional state. Importantly, an interaction of state and distractor type was observed in LPP. These results demonstrate that exogenous attention to emotional distractors is independent from modulating effects of the emotional baseline state at early, automatic stages of processing. However, attention to emotional distractors and affective state interact at later latencies.

Pedophilic brain potential responses to adult erotic stimuli

Cognitive mechanisms associated with the relative lack of sexual interest in adults by pedophiles are poorly understood and may benefit from investigations examining how the brain processes adult erotic stimuli. The current study used event-related brain potentials (ERP) to investigate the time course of the explicit processing of erotic, emotional, and neutral pictures in 22 pedophilic patients and 22 healthy controls. Consistent with previous studies, early latency anterior ERP components were highly selective for erotic pictures. Although the ERPs elicited by emotional stimuli were similar in patients and controls, an early frontal positive (P2) component starting as early as 185 ms was significantly attenuated and slow to onset in pedophilia, and correlated with a clinical measure of cognitive distortions. Failure of rapid attentional capture by erotic stimuli suggests a relative reduction in early processing in pedophilic patients which may be associated with relatively diminished sexual interest in adults.

Age-related changes in emotional face processing across childhood and into young adulthood: Evidence from event-related potentials

Socio-emotional processing is an essential part of development, and age-related changes in its neural correlates can be observed. The late positive potential (LPP) is a measure of motivated attention that can be used to assess emotional processing; however, changes in the LPP elicited by emotional faces have not been assessed across a wide age range in childhood and young adulthood. We used an emotional face matching task to examine behavior and event-related potentials (ERPs) in 33 youth aged 7-19 years old. Younger children were slower when performing the matching task. The LPP elicited by emotional faces but not control stimuli (geometric shapes) decreased with age; by contrast, an earlier ERP (the P1) decreased with age for both faces and shapes, suggesting increased efficiency of early visual processing. Results indicate age-related attenuation in emotional processing that may stem from greater efficiency and regulatory control when performing a socio-emotional task.

Different timing features in brain processing of core and moral disgust pictures: an event-related potentials study

Disgust, an emotion motivating withdrawal from offensive stimuli, protects us from the risk of biological pathogens and sociomoral violations. Homogeneity of its two types, namely, core and moral disgust has been under intensive debate. To examine the dynamic relationship between them, we recorded event-related potentials (ERPs) for core disgust, moral disgust and neutral pictures while participants performed a modified oddball task. ERP analysis revealed that N1 and P2 amplitudes were largest for the core disgust pictures, indicating automatic processing of the core disgust-evoking pictures. N2 amplitudes were higher for pictures evoking moral disgust relative to core disgust and neutral pictures, reflecting a violation of social norms. The core disgust pictures elicited larger P3 and late positive potential (LPP) amplitudes in comparison with the moral disgust pictures which, in turn, elicited larger P3 and LPP amplitudes when compared to the neutral pictures. Taken together, these findings indicated that core and moral disgust pictures elicited different neural activities at various stages of information processing, which provided supporting evidence for the heterogeneity of disgust.

Exogenous (automatic) attention to emotional stimuli: a review

Current knowledge on the architecture of exogenous attention (also called automatic, bottom-up, or stimulus-driven attention, among other terms) has been mainly obtained from studies employing neutral, anodyne stimuli. Since, from an evolutionary perspective, exogenous attention can be understood as an adaptive tool for rapidly detecting salient events, reorienting processing resources to them, and enhancing processing mechanisms, emotional events (which are, by definition, salient for the individual) would seem crucial to a comprehensive understanding of this process. This review, focusing on the visual modality, describes 55 experiments in which both emotional and neutral irrelevant distractors are presented at the same time as ongoing task targets. Qualitative and, when possible, meta-analytic descriptions of results are provided. The most conspicuous result is that, as confirmed by behavioral and/or neural indices, emotional distractors capture exogenous attention to a significantly greater extent than do neutral distractors. The modulatory effects of the nature of distractors capturing attention, of the ongoing task characteristics, and of individual differences, previously proposed as mediating factors, are also described. Additionally, studies reviewed here provide temporal and spatial information-partially absent in traditional cognitive models-on the neural basis of preattention/evaluation, reorienting, and sensory amplification, the main subprocesses involved in exogenous attention. A model integrating these different levels of information is proposed. The present review, which reveals that there are several key issues for which experimental data are surprisingly scarce, confirms the relevance of including emotional distractors in studies on exogenous attention.

Neural responses to cartoon facial attractiveness: An event-related potential study

Animation creates a vivid, virtual world and expands the scope of human imagination. In this study, we investigated the time-courses of brain responses related to the evaluation of the attractiveness of cartoon faces using the event-related potential (ERP) technique. The results demonstrated that N170 amplitude was higher for attractive than for unattractive cartoon faces in males, while the opposite was found in females. Facial attractiveness notably modulated the late positive component (LPC), which might reflect the task-related process of aesthetic appraisal of beauty. The mean LPC amplitude in males was significantly higher for attractive cartoon faces than for unattractive faces, while the LPC amplitude in females did not significantly differ between attractive and unattractive cartoon faces. Moreover, the paint mode (computer graphics, gouache, and stick figure) modulated the early encoding of facial structures and the late evaluative process. The early modulation effect by paint mode may be related to the spatial frequency of the pictures. The processing speed and intensity in females were both higher than those in males. In conclusion, our study, for the first time, reported ERP modulation based on the assessment of cartoon facial attractiveness, suggesting the facilitated selection of attractiveness information at the early stage, and that the attentional enhancement of attractive faces at the late stage only exists in males. This suggests that men's brains are hard-wired to be sensitive to facial beauty, even in cartoons.