Modulating Behavioural and Self-Reported Aggression with Non-Invasive Brain Stimulation: A Literature Review.

Ruben Knehans,Teresa Schuhmann,Jill Lobbestael,Hans Nelen,Joost à Campo,David Roef

doi:10.3390/brainsci12020200

Ruben Knehans, Teresa Schuhmann + Show 4 more

Open Access

https://doi.org/10.3390/brainsci12020200

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Journal: Brain sciences	Publication Date: Jan 31, 2022
Citations: 9	License type: CC BY 4.0

Affiliation: Maastricht University

Abstract

Aggressive behaviour is at the basis of many harms in society, such as violent crime. The efforts to explain, study, and possibly reduce aggression span various disciplines, including neuroscience. The specific brain networks which are involved in the modulation of aggressive behaviour include cortical asymmetry and brain areas such as the dorsolateral prefrontal cortex (DLPFC), the ventrolateral prefrontal cortex (VLPFC), and the ventromedial prefrontal cortex (VMPFC). Recent non-invasive brain stimulation (NIBS) research suggests that both transcranial direct current stimulation (tDCS) and continuous theta burst stimulation (cTBS) can play a role in the modulation of aggressive behaviour by directly changing brain activity. In this review, we systematically explore and discuss 11 experimental studies that aimed to modulate aggressive behaviour or self-reported aggression using NIBS. Out of these 11 studies, nine significantly up- or downregulated aggression by using tDCS or cTBS targeting the DLPFC, VLPFC or VMPFC. The potential applications of these findings span both the clinical and the forensic psychological domains. However, the results are limited by the methodological heterogeneity in the aggression measures used across the studies, and by their generally small sample sizes. Future research should consider improving the localization and specificity of NIBS by employing neuro-navigational instruments and standardized scoring methods.

Highlights

Aggression is at the root of many societal harms, such as violent crime and bullying, and can have a long-lasting detrimental impact on human life
The brain areas targeted by the non-invasive brain stimulation (NIBS) studies are the dorsolateral prefrontal cortex (DLPFC) [14,22,27,49,50], the ventrolateral prefrontal cortex (VLPFC) [45,48,51,57], the inferior frontal gyrus (IFG) [20], and the ventromedial prefrontal cortex (VMPFC) [13]
The downregulation of aggression was found by Molero-Chamizo et al [22], who applied anodal transcranial direct current stimulation (tDCS) bilaterally over the DLPFC, which significantly lowered the self-reported aggressiveness scores for physical aggression (p = 0.001, d = 1.24) and verbal aggression (p = 0.002, d = 1.11) compared to the sham condition

Summary

Introduction

Aggression is at the root of many societal harms, such as violent crime and bullying, and can have a long-lasting detrimental impact on human life. Understanding the underlying neurobiological mechanisms of aggression facilitates the search for effective ways to reduce aggression. Managing aggression can make society as a whole safer by directly preventing inter-personal harm [1]. Lowering aggression can reduce medical/therapy costs for individuals, and prevent the costs of legal proceedings [2]. Treatment-resistant forms of aggression may become treatable via new insights into the underlying mechanisms of aggression. Newer neuroscientific techniques, such as non-invasive brain stimulation (NIBS), are rapidly evolving into instruments with significant clinical relevance for, e.g., treatment-resistant depression [3]. The potential for NIBS to influence aggression is currently unclear because the research is fragmented

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