The behavioral evidence of processing congruences and incongruences between Self- and Other-perspective-related representations during both perspective judgments

Daily, we make visuospatial self-perspective judgments from our actual perspective (SPJ). However, social contexts often require imagining another viewpoint-visuospatial perspective-taking (VPT). VPT is costlier than SPJ, and gets even costlier in autism, schizophrenia, and aging. One explanation is interference from self-related representations. This interference may reflect a mechanism that processes various self- and other-related representations, supported by the temporoparietal junction (TPJ). Moreover, reportedly other-related representations also influence SPJ, though this remains debated. An additional explanation for VPT difficulty in literature is the mental body-schema transformation needed to adopt another perspective at greater angular disparities between perspectives. However, studies often confounded angle with left/right representational incongruence between perspectives. In our previous iEEG study, we found robust TPJ activity during both SPJ and VPT, possibly reflecting the processing of self-other representations. To test whether self-other representations are processed during both perspective judgments, we analyzed behavioral data from the same participants. We categorized trials by an object's left/right congruence between the perspectives. We hypothesized that if self-other representations are processed during both judgments, participants will show greater difficulty in incongruent vs. congruent scenarios during SPJ and VPT. Linear mixed model analysis confirmed this: for both SPJ and VPT, errors were higher on incongruent than congruent trials. These findings show that self-other representations are processed in both SPJ and VPT, and incongruent ones cause interference, highlight left/right congruence as a key factor in VPT studies, and motivate further research with a similar approach on TPJ's role in processing multimodal self-other representations.