Increasing the role of belief information in moral judgments by stimulating the right temporoparietal junction. (October 2015)

• Record Type: Journal Article
• Authors: Sellaro, Roberta; Güroǧlu, Berna; Nitsche, Michael A.; van den Wildenberg, Wery P.M.; Massaro, Valentina; Durieux, Jeffrey; Hommel, Bernhard; Colzato, Lorenza S.
• Is Part Of: Neuropsychologia. Volume 77(2015)
• Page Start: 400
• Page End: 408
• Publication Date: 2015-10
• Subjects: Right temporoparietal junction -- Moral judgment -- Belief -- Transcranial direct current stimulation; Neuropsychology -- Periodicals; Neurology -- Periodicals; Psychophysiology -- Periodicals; Neuropsychologie -- Périodiques; Neuropsychology; Periodicals; Electronic journals; 616.8
• DOI: 10.1016/j.neuropsychologia.2015.09.016
• Languages: English
• ISSNs: 0028-3932

Abstract

Abstract: Morality plays a vital role in our social life. A vast body of research has suggested that moral judgments rely on cognitive processes mediated by the right temporoparietal junction (rTPJ), an area thought to be involved in belief attribution. Here we assessed the role of the rTPJ in moral judgments directly by means of transcranial direct current stimulation (tDCS) – a non-invasive brain stimulation technique that, by applying a weak current to the scalp, allows modulating cortical excitability of the area being stimulated. Participants were randomly and equally assigned to receive anodal stimulation (to increase cortical excitability), cathodal stimulation (to decrease cortical excitability), or sham (placebo) stimulation over the rTPJ before completing a moral judgment task. Participants read stories in which protagonists produced either a negative or a neutral outcome based on either a negative or a neutral belief that they were causing harm or no harm, respectively. Results revealed a selective group difference when judging the moral permissibility of accidental harms (belief neutral, outcome negative), but not intentional harms (belief negative, outcome negative), attempted harms (belief negative, outcome neutral), or neutral acts (belief neutral, outcome neutral). Specifically, participants who received anodal stimulation assigned less blame to accidental harms compared to participants who received cathodal or sham stimulation. These results are consistent with previous findings showing that the degree of rTPJ activation reflects reliance on the agent's innocent intention. Crucially, our findings provide direct evidence supporting the critical role of the rTPJ in mediating belief attribution for moral judgment. Highlights: rTPJ is critical in mediating mental state reasoning during moral judgments. Increasing rTPJ activity via tDCS enhanced the role of belief information. Anodal tDCS of the rTPJ altered selectivity moral judgments for accidental harms. Anodal tDCS led participants to mitigate blame for accidents. The degree of rTPJ activation reflects reliance on the agent's innocent intention.