Transcranial Direct Current Stimulation of the Medial Prefrontal Cortex Affects Judgments of Moral Violations

Abstract

Previous studies show that neural activities in the medial prefrontal cortex (mPFC) are correlated with moral processing during picture viewing tasks. In this study, we applied transcranial direct current stimulation (tDCS) to determine whether this non-invasive brain stimulation technique could modulate the evaluation of moral violations. Sixty-four subjects were randomly recruited, separated into different groups and tested with 42 pairs of pictures depicting moral violations. Each subject was required to rate the pictures two separate times, i.e., before and after tDCS intervention. We found that anodal tDCS (atDCS) increases cortical excitability over the mPFC (between the Fpz and Fp1 positions) as well as the sense of morality and emotional arousal of the subjects. In conclusion, this study indicated that the mPFC plays an important role in moral judgments while modulating ratings of moral violations under tDCS intervention conditions.

Modulating the Social and Affective Brain with Transcranial Stimulation Techniques

“…In this way, these findings indicate that the neuromodulation of the VPFC may impact moral judgment and also highlights probably differences in brain circuitry for emotion processing between men and women (Fumagalli et al, 2010), as previously presented in the literature (Boggio et al, 2008). More recently, in a complementary way, Yuan et al (2017) used a picture judgment task to assess moral judgment and arousal rating. Participants who received anodal tDCS on VMPFC (with reference electrode in the right deltoid) significantly increased moral judgment and arousal rating compared to sham condition.…”

“…Finally, recent work by Riva et al (2018) investigated VMPFC modulation during a moral dilemma task, with the active electrode (anodal or cathodal) over VMPFC and the reference electrode over the occipital area. The findings revealed similar effects to Fumagalli et al (2010) and Yuan et al (2017), where participants receiving anodal tDCS over VMPFC had a higher frequency of utility judgments.…”

Can we rewire criminal mind via non-invasive brain stimulation of prefrontal cortex? Insights from clinical, forensic and social cognition studies

“…We also include a summary of the literature on the effects of NIBS on empathy and Theory of Mind (ToM) in non-clinical populations, as these social cognition abilities are considered reliable predictors of criminal conduct and/or people compliance with social and legal rules (Gómez, 2021 ; Huesmann et al, 2002 ; Swogger et al, 2015 ). We did not include the literature on the effects of NIBS on morality given that several recent and exhaustive review articles are available in the field (Darby & Pascual-Leone, 2017 ; Yuan et al, 2017 ).…”