Heterogeneity of social cognition in temporo-parietal junction: Overlapping yet distinct representation between visual perspective-taking and theory of mind

Visual perspective taking (VPT), particularly level 2 VPT (VPT2), which allows an individual to understand that the same object can be seen differently by others, is related to the theory of mind (ToM), because both functions require a decoupled representation from oneself. Although previous neuroimaging studies have shown that VPT and ToM activate the temporo-parietal junction (TPJ), it is unclear whether common neural substrates are involved in VPT and ToM. To clarify this point, the present study directly compared the TPJ activation patterns of individual participants performing VPT2 and ToM tasks using functional magnetic resonance imaging and within-subjects design. VPT2-induced activations were compared with activations observed during a mental rotation task as a control task, whereas ToM-related activities were identified with a standard ToM localizer using false-belief stories. A whole-brain analysis revealed that VPT2 and ToM activated overlapping areas in the posterior part of the TPJ. By comparing the activations induced by VPT2 and ToM in individual participants, we found that the peak voxels induced by ToM were located significantly more anteriorly and dorsally within the bilateral TPJ than those measured during the VPT2 task. We further confirmed that these activity areas were spatially distinct from the nearby extrastriate body area (EBA), visual motion area (MT+), and the posterior superior temporal sulcus (pSTS) using independent localizer scans. Our findings revealed that VPT2 and ToM have distinct representations, albeit partially overlapping, indicating the functional heterogeneity of social cognition within the TPJ. Significance StatementThe temporo-parietal junction (TPJ) is consistently activated by social cognitive tasks such as visual perspective taking (VPT) and theory of mind (ToM) tasks. The present study investigated whether VPT and ToM have the same neural substrates within the TPJ using functional magnetic resonance imaging (fMRI) with a within-subjects design. While VPT and ToM tasks activated overlapping areas in the posterior part of the TPJ, the individual peak voxels induced by ToM were located significantly more anteriorly and dorsally compared with those observed during the VPT task. Moreover, they were spatially distinct from the nearby functional modules, such as the extrastriate body area, visual motion area, and posterior superior temporal sulcus. Our findings reveal the heterogeneity of social cognition representation within the TPJ.