PT  - JOURNAL ARTICLE
AU  - A. K. Martin
AU  - J. Huang
AU  - M. Meinzer
TI  - Dissociable roles for the rTPJ and dmPFC in self-other processing: a HD-tDCS study
AID  - 10.1101/306183
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 306183
4099  - http://biorxiv.org/content/early/2018/04/24/306183.1.short
4100  - http://biorxiv.org/content/early/2018/04/24/306183.1.full
AB  - Background Social interaction relies on the integration and distinction of self and other. The dorsomedial prefrontal cortex (dmPFC) and the right temporoparietal junction (rTPJ) are two regions consistently associated with social processes. Theories of rTPJ function in social cognition include self-other distinction, self-inhibition, or embodied mental rotation, whereas the dmPFC is associated with a wide range of social functions involving understanding and encoding information pertaining to others. However, to date, no study has provided causal evidence for dissociable roles of the rTPJ and dmPFC in social cognition.Method 52 healthy young adults were stratified into two studies and received either dmPFC or rTPJ anodal HD-tDCS in a sham-controlled, double-blinded, repeated measures design. Subjects completed a social cognitive battery measuring self-other processing across an implicit and explicit level one (line-of-sight) and level two (mental rotation) visual perspective taking tasks (VPT), as well as self and other encoding effects on episodic memory in order to test the self-reference effect (SRE).Results Stimulation of the dmPFC selectively enhanced integration of the other perspective into self as indexed by an increase in congruency effect (incongruent-congruent) across both explicit VPT tasks. It also removed the SRE in episodic memory, indexed by increasing the recognition of other-encoded words and reducing the recognition of self-encoded words. Stimulation of the rTPJ resulted in improved inhibition of the self-perspective during level two VPT only, as indexed by a reduction of the congruency effect when taking the other perspective.Conclusion Our results provide the first causal evidence for dissociable roles of the dmPFC and rTPJ in social cognition. This research supports theories suggesting that rTPJ facilitates embodied mental rotation, whereas the dmPFC integrates information relevant to the other into that of the self.