Disrupting the right prefrontal cortex alters moral judgement

Abstract

Humans daily face social situations involving conflicts between competing moral decision. Despite a substantial amount of studies published over the past 10 years, the respective role of emotions and reason, their possible interaction, and their behavioural expression during moral evaluation remains an unresolved issue. A dualistic approach to moral evaluation proposes that the right dorsolateral prefrontal cortex (rDLPFc) controls emotional impulses. However, recent findings raise the possibility that the right DLPFc processes emotional information during moral decision making. We used repetitive transcranial magnetic stimulation (rTMS) to transiently disrupt rDLPFc activity before measuring decision making in the context of moral dilemmas. Results reveal an increase of the probability of utilitarian responses during objective evaluation of moral dilemmas in the rTMS group (compared to a SHAM one). This suggests that the right DLPFc function not only participates to a rational cognitive control process, but also integrates emotions generated by contextual information appraisal, which are decisive for response selection in moral judgements.

Interfering with activity in the dorsomedial prefrontal cortex via TMS affects social impressions updating

“…Similar stimulation parameters (i.e., fixed intensity of stimulation, 15 minutes of stimulation) have been used before to suppress activity of prefrontal regions prior to task requiring social judgments (e.g., reciprocal fairness, moral judgments), with the effects of stimulation continuing after the end of the actual stimulation (e.g., Baumgartner, Knoch, Hotz, Eisenegger, & Fehr, 2011;Eisenegger, Treyer, Fehr, & Knoch, 2008;Knoch, Pascual-Leone, Meyer, Treyer, & Fehr, 2006;Tassy et al, 2012). Talairach coordinates (Talairach & Tournoux, 1988) for the dmPFC were x = 1.5, y = 31.5, and z = 35.5; these coordinates were taken from previous neuroimaging work demonstrating an activation of this region during social impression updating (Mende-Siedlecki et al, 2012).…”

The modulating effects of brain stimulation on emotion regulation and decision-making

“…When measuring rTMS's effects using the "dilemma" scenarios selected from a battery developed by Greene et al [28], LF rTMS over the right DLPFC increased utilitarian responses during objective evaluation of moral dilemmas, compared to a sham group. For the results, the authors suggested that the right DLPFC stimulated by LF rTMS induced participants toward a rational cognitive control process, and integrated emotions caused by contextual information appraisal in moral judgments [72]. Buckholtz et al [9] studied blameworthiness and punishment decisions using LF rTMS over the DLPFC.…”

“…In summary, in decision-making studies related to emotion, rTMS modulates delayed discounting [13,69], food choice [10], moral judgment [72], and blameworthiness and punishment decisions [9]. In decision-making studies relevant to cognitive functions, rTMS affects visuospatial attention [71], perception [57], object identification [77], spatial working memory [36], function and manipulation tool knowledge [33], and visuomotor tasks [25].…”

“This Position Requires Some Alteration of Your Brain”: On the Moral and Legal Issues of Using Neurotechnology to Modify Employees

“…• Implicit racial bias -propranolol has been used to virtually abolish implicit racial bias in subjects, without affecting any explicit racial prejudice measures (Terbeck 2012). • Utilitarian Moral Judgment-repetitive TMS disrupting activity in the right dorsolateral prefrontal cortex increases utilitarian moral judgments (Tassy 2012). TMS disruption of the right temporoparietal junction has been shown to lead subjects to pay less attention to actors' mental states and make moral judgments based more on consequences (Young 2010).…”