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

Abstract

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 sex offenders with child victims (SOC) with PD display an automatic attention bias for child-related 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 the present pre-registered pilot study, we were the first to investigate whether acutely increasing prefrontal activity could reduce the putative pedophilic attention bias. To do so, we delivered a single 20-minute session of active anodal vs. 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. No significant tDCS effect on visual attention to sexually salient stimuli emerged during or immediately after stimulation. From a qualitative perspective, observations were in line with a bias for sexually preferred vs. non-preferred stimuli in patients but not in controls. Importantly, active vs. sham tDCS reduced this bias across outcome measures in patients but not in controls. Based on these preliminary findings, it is worth further investigating the possibility of using brain stimulation as a therapeutic intervention for PD. Methodological improvements were also identified and discussed to assist future research.

Viewing Time Measures of Sexual Interest and Sexual Offending Propensity: An Online Survey of Fathers

“…Both offending and community men might be reluctant to disclosing their sexual attraction to children, albeit for different reasons (e.g., fear of legal repercussions and social desirability, respectively) and this might explain the low concordance. Alternatively, and as argued in a previous study (Pezzoli et al, 2020), it is possible that sexually salient images of children might capture participants' attention more than sexually salient images of adults due to their surprising or disturbing nature, therefore prolonging VTs. In other words, we cannot directly discern whether some fathers gazed longer at child images because of their sexual interest in children or, rather, because those images were particularly surprising or disturbing.…”

“…The resulting lack of normative data on the link between VTs and sexual interest leaves it unclear how unusual a particular VT pattern might be, therefore making it difficult to establish a critical score that can identify those who are likely to be attracted to children, based on their VT patterns (Seto, 2017a , b ). For instance, one laboratory study found that men attracted to sexually mature adults and men attracted to children gazed longer at child compared to adult sexual stimuli (Pezzoli et al, 2020 ). Conceivably, child sexual stimuli can be highly salient in a non-sexual way (e.g., distressing or disturbing) and, as a result, capture the attention of both sexual interest groups alike.…”