The Effects of Acute Transcranial Direct Current Stimulation on Attentional Bias in Pedophilic Disorder: A Preregistered Pilot Study

Abstract

Objectives: Individuals with pedophilic disorder (PD) experience personal and interpersonal difficulties and are at risk of sexually offending against children. As such, innovative and empirically validated treatments are needed. Recent studies have indicated that men who have sexually offended against children (SOC) with PD display an automatic attention bias for childrelated stimuli as well as reduced activity in the dorsolateral prefrontal cortex (dlPFC), a brain area involved in cognitive control, including control over sexual arousal. In this preregistered pilot study, we are the first to investigate whether acutely increasing prefrontal activity could reduce the putative pedophilic attention bias. Materials and Methods:We delivered a single 20-min session of active anodal versus sham transcranial direct current stimulation (tDCS) over the left dlPFC to 16 SOC with PD and 16 matched healthy controls, while they performed a task requiring controlled attention to computer-generated images of clothed and nude children and adults. We collected responses unobtrusively by recording eye movements.Results: Our results did not support the presence of the expected automatic attention bias across outcome measures. Nonetheless, we found a response facilitation with child targets in patients and, unexpectedly, in controls, likely due to unwanted salience effects. Active versus sham tDCS reduced this bias across groups, as indicated by a significant group*condition interaction (p = 0.04). However, no attentional bias and no tDCS effects on attentional responses to child and adult images emerged following tDCS.Conclusions: These results suggest enhanced cognitive control in response to salient stimuli during active tDCS. Thus, to assist future studies on neuromodulation in PD, we provide suggestions for design improvement.

The Role of Atypical Sexual Preference and Behavior in Neuroelectrophysiological Research of Human Sexual Behavior

“…To our knowledge, no study has been published until the publication date of the Ziogas et al ( 2020 ) article, where transcranial direct current stimulation (tDCS) or transcranial magnetic stimulation (TMS) was applied in patients with sexual preference disorders. However, there is a preregistered study by Pezzoli et al ( 2020 ) which was published after the release of Ziogas et al In the Pezzoli et al study, automatic attention bias for child versus adult visual stimuli was investigated in 16 pedophilic child sexual offenders and matched healthy control subjects while receiving a tDCS over the left dorsolateral prefrontal cortex (dlPFC), a brain region that has been implicated in neural processes of cognitive control and sexual arousal (Poeppl et al, 2013 ; Walter et al, 2007 ). Although a differentiation between offense statuses in the pedophilic study group would have been very interesting for the exploration of potential longitudinal effects, electric stimulation might be a promising approach with close clinical implications.…”

What can the eyes tell us about atypical sexual preferences as a function of sex and age? Linking eye movements with child-related chronophilias

“…Evidence of its usefulness has been proven in studies on attentional biases towards emotional stimuli in clinical disorders [ 96–99 ]. It has been tested with sexual stimuli in a recent study [ 94 ], and a recently published study used this paradigm in assessing the impact of a single session of transcranial stimulation on the response biases of pedophilic compared to non-pedophilic men [ 100 ].…”

Tower of Babel or Lighthouse? The State of Research on Neuroelectric Correlates of Human Sexuality: A Response to the Commentaries

“…Ultimately, Pfaus ( 2021 ) as well as the final comment by Ristow and Kärgel ( 2021 ) pointed at the potential of studies including transcranial direct current stimulation (tDCS), the latter explicitly mentioning a study (Pezzoli et al, 2021 ) that three of us (AZ, AM, and PS) were involved with. The appealing promise of tDCS is that brain activation can be modulated in a reversible and non-invasive manner, thus opening up the possibility of experimental interventions that target particular areas specifically.…”