Department of Psychology, Nanyang Technological University, Singapore 637332,
Departments of Criminology, Psychiatry, and Psychology, Jerry Lee Center of Criminology, and.
J Neurosci. 2018 Jul 18;38(29):6505-6512. doi: 10.1523/JNEUROSCI.3317-17.2018. Epub 2018 Jul 2.
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 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, parallel-group, randomized trial, 81 human adults (36 males, 45 females) were randomly assigned to an active ( = 39) or placebo ( = 42) condition, and then followed up 1 d 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. Compared with the sham controls, participants who received anodal stimulation reported being less likely to commit physical and sexual assault ( < 0.01). They also judged aggressive acts as more morally wrong ( < 0.05). Perceptions of greater moral wrongfulness regarding the aggressive acts accounted for 31% of the total effect of tDCS on intentions to commit aggression. Results provide experimental evidence that increasing activity in the prefrontal cortex can reduce intentions to commit aggression and enhance perceptions of the moral wrongfulness of the aggressive acts. Findings shed light on the biological underpinnings of aggression and theoretically have the potential to inform future interventions for aggression and violence. Aggressive 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, parallel-group, 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 toward reducing aggression.
尽管前额叶脑损伤是与攻击行为相关的最可重复的脑成像发现之一，但对于该脑区的因果作用知之甚少。本研究旨在检验使用经颅直流电刺激（tDCS）刺激背外侧前额叶是否会降低实施攻击行为的可能性，以及这种关系的潜在机制。采用双盲、分层、安慰剂对照、平行组、随机试验，将 81 名成年人（男性 36 名，女性 45 名）随机分为真刺激组（n = 39）和假刺激组（n = 42），然后在实验结束后 1 天进行随访。使用假设情节和行为任务分别评估实施攻击行为的意图和行为攻击。次要结果是对攻击行为的道德错误感知。与假刺激对照组相比，接受阳极刺激的参与者报告实施身体和性攻击的可能性较小（<0.01）。他们还判断攻击行为的道德错误性更高（<0.05）。对攻击行为的更大道德错误感知占 tDCS 对攻击意图总效应的 31%。结果提供了实验证据，表明增加前额叶皮层的活动可以降低实施攻击的意图，并增强对攻击行为的道德错误感知。这些发现揭示了攻击行为的生物学基础，从理论上讲，有可能为攻击和暴力的未来干预措施提供信息。攻击行为会带来严重的公共健康风险。了解攻击行为的病因对减少暴力至关重要。对攻击行为的神经基础的研究在很大程度上支持了相关性而非因果性的解释，并且前额叶-攻击关系的中介过程仍有待充分阐明。通过双盲、分层、安慰剂对照、平行组、随机试验，本研究检验了前额叶皮层的上调是否会降低实施攻击的可能性。结果提供了实验证据，表明增加前额叶皮层的活动可以降低实施攻击行为的意图。它们还揭示了道德判断作为一种可能将前额叶缺陷与攻击联系起来的机制，并从理论上讲，有可能为减少攻击的未来方法提供信息。
