Temporoparietal Junction Selectively Mediates Social Projection in Mentalizing

Area of Science:

• Neuroscience
• Social Cognition
• Cognitive Psychology

Background:

• Mentalizing involves inferring others' mental states, often using social projection (self-as-proxy) leading to self-other mergence (SOM).
• The neural underpinnings of SOM and its relationship to other social cognition frameworks remain unclear.

Purpose of the Study:

• To investigate the neural basis of self-other mergence (SOM) during social projection.
• To differentiate the roles of the dorsal anterior cingulate cortex (dACC) and temporoparietal junction (TPJ) in mentalizing and metacognition.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used during a dyadic task assessing self- and partner confidence.
• Effective connectivity analysis examined the relationship between dACC and TPJ activity.
• Transcranial magnetic stimulation (TMS) was employed to disrupt TPJ function.

Main Results:

• Self-confidence, crucial for SOM, was encoded in the dACC during metacognition.
• The TPJ showed effective connectivity with the dACC, tracking SOM magnitude.
• Partner's confidence was distinctly represented in the dorsomedial prefrontal cortex.
• Disrupting TPJ activity with TMS causally reduced the SOM effect.

Conclusions:

• The study identifies a distinct neural mechanism for social projection, mediated by TPJ-dACC interactions.
• Findings clarify the role of the TPJ in social projection during mentalizing.
• This research advances understanding of how the self scaffolds social cognition.