Citation

Choy O, Raine A, Hamilton RH. J. Neurosci. 2018; 38(29): 6505-6512.

Affiliation

Department of Neurology, University of Pennsylvania, 3710 Hamilton Walk, Philadelphia, PA 19104.

Copyright

(Copyright © 2018, Society for Neuroscience)

DOI

10.1523/JNEUROSCI.3317-17.2018

PMID

29967006

Abstract

Although prefrontal brain impairments are one of the best-replicated brain imaging findings in relation to aggression, little is known about the causal role of this brain region. This study tests whether stimulating the dorsolateral prefrontal cortex (DLPFC) using transcranial direct current stimulation (tDCS) reduces the likelihood of engaging in aggressive acts, and the mechanism underlying this relationship. In a double-blind, stratified, placebo-controlled, randomized trial, 81 human adults (36 males, 45 females) were randomly assigned to an active (N = 39) or placebo (N = 42) condition, and followed up one day after the experiment session. Intentions to commit aggressive acts and behavioral aggression were assessed using hypothetical vignettes and a behavioral task, respectively. The secondary outcome was the perception of the moral wrongfulness of the aggressive acts. Participants who received anodal stimulation reported being less likely to commit physical and sexual assault (p <.01), and judged aggressive acts as more morally wrongful (p <.05) compared to the sham controls. 31% of the total effect of tDCS on intentions to commit aggression was accounted for by perceptions of greater moral wrongfulness regarding the aggressive acts.

RESULTS provide experimental evidence that increasing activity in the prefrontal cortex can reduce intentions to commit aggression and enhance perceptions of moral judgment.

FINDINGS shed light on the biological underpinnings of aggression and theoretically have the potential to inform future interventions for aggression and violence.Trial Registration ClinicalTrials.gov identifier: NCT02427672SIGNIFICANCE STATEMENTAggressive behaviors pose significant public health risks. Understanding the etiology of aggression is paramount to violence reduction. Investigations of the neural basis of aggression have largely supported correlational, rather than causal interpretations, and the mediating processes underlying the prefrontal-aggression relationship remain to be well-elucidated. Through a double-blind, stratified, placebo-controlled, randomized trial, this study tested whether upregulation of the prefrontal cortex reduces the likelihood of engaging in aggression.

RESULTS provide experimental evidence that increasing prefrontal cortical activity can reduce intent to commit aggressive acts. They also shed light on moral judgment as one mechanism that may link prefrontal deficits to aggression and in theory, have the potential to inform future approaches towards reducing aggression.

Copyright © 2018 the authors.

Language: en