Neuroimaging in pedophilia

[Specificity of visual event-related potentials to subthreshold presentation of erotic pictures in pedophilia]

OBJECTIVE

To study visual event-related potentials (ERPs) associated with presentation of erotic pictures in backward masking condition in order to investigate perception, attention and information processing underlying the initiation and maintenance of abnormal sexual behavior in pedophilia.

MATERIAL AND METHODS

Participants (58 males committed sexual offenses against children) were divided into the pedophilia group (n=38) and the control group without disorders of sexual preference (n=20). Three types of stimuli were used: neutral pictures of nature (S1), adult heterosexual erotic pictures (S2) and erotic pictures with children (S3). Posterior N1 (N140) and anterior N1 (N120) and P3 (P320) ERP components were included in analysis.

RESULTS

In both groups, the perception of erotic stimuli was accompanied by a significant increase in the amplitude and prolongation of the latency of the N140 and P320 components (p<0.001). N140 changes were characterized by right-hemispheric bias in both groups, however, asymmetry was observed for amplitude in the control group, and for latency - in the pedophilia group; besides, reactivity to S3 stimuli was weaker than to S2 ones in the pedophilia group. N120 amplitude was elevated significantly in response to S2 stimuli in the control group, and no changes were found in the pedophilia group. Between-group differences were revealed for early negative components N140 and N120, which parameters were entered as predictors into classification model based on discriminant analysis. The obtained accuracy of model was 87.23%.

CONCLUSION

The specificity of neurophysiological reactions to erotic pictures in pedophilic patients corroborates the concept of disease as general neurodevelopmental disorder.

Altered Neural and Behavioral Response to Sexually Implicit Stimuli During a Pictorial-Modified Stroop Task in Pedophilic Disorder

Background

Pedophilic disorder (PD) entails sexual attraction to prepubertal children. A risk factor for committing child sexual abuse in PD is impaired cognitive control. However, the underlying neurocognitive mechanisms remain unclear.

Methods

We performed a case-control study including 51 self-identified and help-seeking males with PD and 55 matched healthy control subjects. Functional magnetic resonance imaging and a pictorial-modified Stroop task involving computer-generated sexually implicit images were used to measure response time and brain activation. Increases in response time during the pictorial-modified Stroop task are presumably due to image-induced interference in executive functions required for task performance.

Results

In PD, during the presentation of images of children compared with adults, we found increased response time (p = .005; 848 ± 92 ms vs. 826 ± 88 ms), and compared with healthy control subjects, we found increased activation in the occipital, temporal (bilateral hippocampus), parietal, frontal, cingulate, and left insular cortices; caudate (bilaterally); thalamus (mediodorsal); and cerebellum.

Conclusions

Presentation of child images was associated with response interference in PD and increased engagement of brain regions involved in the processing of sexual stimuli, visual perception, self-referential thought, and executive function. We conclude that processing of child images is associated with functional and behavioral alterations in PD.

[Neurophysiological correlates of pedophilia: a study of EEG evoked oscillations]

OBJECTIVE

To study the changes of evoked EEG oscillations in response to erotic visual stimuli to identify specific patterns in subjects with different variants of pedophilia.

MATERIAL AND METHODS

Forty-eight right-handed male offenders who have committed sexual acts against children participated in the study. Seventeen subjects without paraphilic disorders were included in group 1, 17 subjects with heterosexual pedophilia were included in group 2, and 13 subjects with homosexual pedophilia were included in group 3. The stimuli were colored pictures of neutral, heterosexual normative, hetero- and homosexual pedophilic content shortly demonstrated with backward masking. Spectral power of delta, theta, alpha, and beta evoked oscillations (EO) was analyzed. Further, the number of significant changes of EO power in response to erotic stimuli relative to neutral ones was calculated, and topography changes of EO power in response to specific erotic pictures compared to neutral ones were analyzed for each group.

RESULTS

The diminished number of significant reactions to specific stimuli was found in the pedophilia groups (18 and 4 in groups 2 and 3, respectively) in comparison with the group without paraphilia (25). The specific changes of EO power in response to specific erotic visual pictures were found for each group. Increased power of delta, theta and alpha EO in the 104-164 ms time window, and decreased power of alpha EO in the 344-920 ms time window were found in group 1. In group 2, specific stimulation elicited decline of delta and theta EO power, possibly related to impaired motivational and emotional aspects of erotic stimuli perception. The weak changes were found in group 3 - increased power of beta EO in the frontal area.

CONCLUSION

The obtained frequency and spatial patterns of EO changes in response to erotic visual pictures are related to specificity of hetero- and homosexual pedophilia.

Affective disorders and sexual function: from neuroscience to clinic

PURPOSE OF REVIEW

Sexual dysfunction is a frequent issue in patients with affective disorders, affecting its quality of life and posing challenges to the approach of these patients.

RECENT FINDINGS

In recent years, human sexuality has attracted interest from the scientific community, and today we have a much deeper knowledge of the mechanisms involved in the sexual response. Paraphilias or sexual dysfunctions like low sexual desire, premature ejaculation, and erectile dysfunction, are frequent in affective disorders, and the frequency of each sexual problem varies according to the affective disorder. Comparing what is currently known about the sexual response with the main neurobiological findings of depressive, anxiety, obsessive-compulsive and posttraumatic stress disorders, it is possible to better understand specific sexual complaints of patients with these disorders.

SUMMARY

A better understanding of sexual function in affective disorders may help clinicians to choose treatments more suited to specific needs of these patients. Although the current state of science already allows us to have some understanding about sexual function in affective disorders, this critical area of research is still in its infancy, waiting for more investment.

The Biological Treatment of Paraphilic Disorders: an Updated Review

Paraphilic disorders are characterized by atypical sexual interests, fantasies, and behaviors that are subjectively distressing to patients or pose a risk of harm to others. By their very nature, some paraphilic disorders may predispose an individual to commit sexual offenses. The biological treatment of paraphilic disorders, then, is of paramount importance for psychiatry and society at large. Three categories of pharmacologic agents commonly used to treat paraphilic disorders are selective serotonin reuptake inhibitors, synthetic steroidal analogs, and gonadotropin-releasing hormone analogs. Each medication uses a different mechanism of action and has different effects on the physiological and psychological features of paraphilic disorders. In general, these medications have limited high-quality research to support their use. Despite this, some authors have proposed treatment algorithms for individuals with paraphilic disorders of varying severity. These guidelines offer clinicians potentially useful, rational approaches to assessing treatment need in individuals with paraphilic disorders. Recent neuroimaging research suggests that functional magnetic resonance imaging may offer further promise in effectively assessing paraphilic disorders to help direct treatment options.

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.

Neuroimaging: beginning to appreciate its complexities

For over a century, scientists have sought to see through the protective shield of the human skull and into the living brain. Today, an array of technologies allows researchers and clinicians to create astonishingly detailed images of our brain's structure as well as colorful depictions of the electrical and physiological changes that occur within it when we see, hear, think and feel. These technologies-and the images they generate-are an increasingly important tool in medicine and science. Given the role that neuroimaging technologies now play in biomedical research, both neuroscientists and nonexperts should aim to be as clear as possible about how neuroimages are made and what they can-and cannot-tell us. Add to this that neuroimages have begun to be used in courtrooms at both the determination of guilt and sentencing stages, that they are being employed by marketers to refine advertisements and develop new products, that they are being sold to consumers for the diagnosis of mental disorders and for the detection of lies, and that they are being employed in arguments about the nature (or absence) of powerful concepts like free will and personhood, and the need for citizens to have a basic understanding of how this technology works and what it can and cannot tell us becomes even more pressing.

Changed processing of visual sexual stimuli under GnRH-therapy--a single case study in pedophilia using eye tracking and fMRI

BACKGROUND

Antiandrogen therapy (ADT) has been used for 30 years to treat pedophilic patients. The aim of the treatment is a reduction in sexual drive and, in consequence, a reduced risk of recidivism. Yet the therapeutic success of antiandrogens is uncertain especially regarding recidivism. Meta-analyses and reviews report only moderate and often mutually inconsistent effects.

CASE PRESENTATION

Based on the case of a 47 year old exclusively pedophilic forensic inpatient, we examined the effectiveness of a new eye tracking method and a new functional magnetic resonance imaging (fMRI)-design in regard to the evaluation of ADT in pedophiles. We analyzed the potential of these methods in exploring the impact of ADT on automatic and controlled attentional processes in pedophiles. Eye tracking and fMRI measures were conducted before the initial ADT as well as four months after the onset of ADT. The patient simultaneously viewed an image of a child and an image of an adult while eye movements were measured. During the fMRI-measure the same stimuli were presented subliminally. Eye movements demonstrated that controlled attentional processes change under ADT, whereas automatic processes remained mostly unchanged. We assume that these results reflect either the increased ability of the patient to control his eye movements while viewing prepubertal stimuli or his better ability to manipulate his answer in a socially desirable manner. Unchanged automatic attentional processes could reflect the stable pedophilic preference of the patient. Using fMRI, the subliminal presentation of sexually relevant stimuli led to changed activation patterns under the influence of ADT in occipital and parietal brain regions, the hippocampus, and also in the orbitofrontal cortex. We suggest that even at an unconscious level ADT can lead to changed processing of sexually relevant stimuli, reflecting changes of cognitive and perceptive automatic processes.

CONCLUSION

We are convinced that our experimental designs using eye tracking and fMRI could prospectively add additional and valuable information in the evaluation of ADT in paraphilic patients and sex offenders. But with respect to the limited significance of this single case study, these first results are preliminary and further studies have to be conducted with healthy subjects and patients.

[Pedophilia: etiology, diagnostics and therapy]

Child sexual abuse is one of the most destructive events for healthy child development. Following psychiatric classification systems, pedophilia must be distinguished from child sexual abuse. Approximately only one half of all child abusers fulfill the diagnostic criteria for pedophilia which is defined as a persistent or dominating sexual preference for prepubescent children characterized by persistent thoughts, fantasies, urges, sexual arousal or behavior. This article describes the diagnostic criteria and potential differential diagnoses as well as epidemiological and etiological findings. From an etiological point of view multifactorial mechanisms are currently considered to be responsible especially genetic factors, learning theoretical and neurobiological factors. Psychotherapeutic and pharmaceutical treatment options will be discussed. According to the current state of knowledge cognitive-behavioral psychotherapy is the method of choice in the treatment of pedophilia and has demonstrated positive treatment effects in meta-analyses regarding relapse prevention. Medicinal treatment of pedophilia is only indicated for severe forms of pedophilia. Important aspects of risk management in the treatment of pedophilia and aspects which must be considered in the forensic psychiatric assessment are presented.

Philosophical issues in the paraphilias

PURPOSE OF REVIEW

Controversies surrounded the development of paraphilias in the Diagnostic and Statistical Manual of Mental Disorders (DSM) 5. This review examines the philosophical issues that emerge from an analysis of those debates and current literature.

RECENT FINDINGS

The resolution of controversies in the publication of the DSM 5 drew upon the available evidence, theories of mental disorder, and normative assumptions. The rise of the Internet presents difficult challenges in this field.

SUMMARY

Numerous philosophical assumptions underlie the psychiatric understandings of paraphilias. The focus here is on the nosological issues such as boundary justification for the determinations of normative and nonnormative human sexuality; the importance of not collapsing the distinction between mental disorder and crime, and the relationship between fantasy and action; epistemological questions of perspectivity, reasons-giving, and relationship of communication to truth claims; and sex differences not only in the paraphilias but also in the social context in which sex is formed and given expression.

The neuroethics and neurolaw of brain injury

Neuroethics and neurolaw are fields of study that involve the interface of neuroscience with clinical and legal decision-making. The past two decades have seen increasing attention being paid to both fields, in large part because of the advances in neuroimaging techniques and improved ability to visualize and measure brain structure and function. Traumatic brain injury (TBI), along with its acute and chronic sequelae, has emerged as a focus of neuroethical issues, such as informed consent for treatment and research, diagnostic and prognostic uncertainties, and the subjectivity of interpretation of data. The law has also more frequently considered TBI in criminal settings for exculpation, mitigation and sentencing purposes and in tort and administrative law for personal injury, disability and worker's compensation cases. This article provides an overview of these topics with an emphasis on the current challenges that the neuroscience of TBI faces in the medicolegal arena.