Wanqing Li, Xiaoqin Mai, Chao Liu
7 min
The Default Mode Network (DMN) is classically known for its activity during rest and self-referential thought. However, recent evidence increasingly links the DMN to social cognition, including emotion perception, empathy, Theory of Mind (ToM), and moral judgment. This review examines how connectivity between DMN regions—and their interactions with other brain networks—enables humans to navigate complex social environments.
A central insight from the reviewed research is that the Medial Prefrontal Cortex (MPFC) acts as a hierarchically organized center for social processing. As social tasks increase in complexity, the engaged brain regions shift along the frontal cortex:
By mapping these connectivity patterns, the authors propose that the DMN provides a framework for using past experiences and self-referential models to interpret current social scenarios. This hierarchical organization suggests that social cognition involves a transition from automatic emotional responses (vMPFC) to higher-level, effortful cognitive evaluations (dMPFC). This perspective is particularly relevant for understanding neurodevelopmental and psychiatric conditions, such as autism and psychopathy, where disrupted DMN connectivity has been consistently observed. Future research should prioritize causal methods—such as TMS and pharmacological interventions—to better confirm these functional roles and map the causal flow of information during social interactions.
The Default Mode Network (DMN) has been found to be involved in various domains of cognitive and social processing. The present article will review brain connectivity results related to the DMN in the fields of social understanding of others: emotion perception, empathy, theory of mind, and morality. Most of the reviewed studies focused on healthy subjects with no neurological and psychiatric disease, but some studies on patients with autism and psychopathy will also be discussed. Common results show that the medial prefrontal cortex (MPFC) plays a key role in the social understanding of others, and the subregions of the MPFC contribute differently to this function according to their roles in different subsystems of the DMN. At the bottom, the ventral MPFC in the medial temporal lobe (MTL) subsystem and its connections with emotion regions are mainly associated with emotion engagement during social interactions. Above, the anterior MPFC (aMPFC) in the cortical midline structures (CMS) and its connections with posterior and anterior cingulate cortex contribute mostly to making self-other distinctions. At the top, the dorsal MPFC (dMPFC) in the dMPFC subsystem and its connection with the temporo-parietal junction (TPJ) are primarily related to the understanding of other's mental states. As behaviors become more complex, the related regions in frontal cortex are located higher. This reflects the transfer of information processing from automatic to cognitive processes with the increase of the complexity of social interaction. Besides the MPFC and TPJ, the connectivities of posterior cingulate cortex (PCC) also show some changes during tasks from the four social fields. These results indicate that the DMN is indispensable in the social understanding of others.
Sam: So even when the language sounds causal, we need to know which method produced it.
Alex: Yes. The authors warn that some estimates of direction can reflect differences in the timing of blood-flow responses across regions. That's one reason to distinguish a proposed information-processing account from demonstrated causal machinery.
Sam: Let's build that account. Where do the authors put the main division of labor?
Alex: They focus on the medial prefrontal cortex, the inner-facing region toward the front of the brain. Their proposal distinguishes lower, anterior, and upper portions. The lower portion's connections with emotional regions are especially prominent in emotion perception and empathy.
Sam: Give me a comparison that shows why those connections matter, rather than just the frontal region itself.
Alex: In an emotional-conflict task using fearful and happy faces, a frontal midline region was negatively coupled with the amygdala. That relationship was stronger during high-conflict than low-conflict resolution trials. Its strength predicted successful conflict resolution.
Sam: Negative coupling can sound like one region suppressing another. Does the review justify that interpretation?
Alex: Not automatically. The review explicitly cautions that negative correlations can depend on removing the whole-brain signal during analysis. That processing step can produce negative relationships even when they weren't initially present. The safe description is the measured association, not proven inhibition.
Sam: Then empathy adds another problem: recognizing whose emotion you're dealing with. How does that enter the proposed map?
Alex: The authors emphasize the anterior portion of the inner frontal cortex for distinguishing self from other. Their definition of empathy includes generating a corresponding feeling while recognizing that someone else caused it. Sharing emotion and identifying its source are related, but different, demands.
Sam: Is there a concrete social comparison behind that distinction?
Alex: One study compared watching a friend experience social exclusion with watching a stranger experience it. The friend condition produced stronger connectivity between the medial frontal region and areas involved in emotional processing, including the insula.
Sam: That fits the idea that our relationship with the person changes the response. But does it establish that the connection distinguishes self from other?
Alex: No. The authors interpret the friend as closer to the self, making that result consistent with their account. The comparison demonstrates a relationship-dependent connectivity difference. It doesn't isolate self–other distinction as the only explanation.
Sam: Now move from feeling with someone to understanding what they believe. What changes in the proposed network?
Alex: That's theory of mind: explaining or predicting behavior through another person's beliefs, intentions, and feelings. Here the review emphasizes the upper medial frontal region. It often connects with the temporo-parietal junction, where the temporal and parietal lobes meet.
Sam: Are emotion and intention treated as the same kind of inference?
Alex: Not entirely. A study comparing emotion inference with intention inference found differences within that junction region. More anterior portions were more active for emotion inference and more strongly connected with the lower medial frontal region. More posterior portions were more active for intention inference.
Sam: So the map isn't just “emotion down here, thinking up there.” The connections depend on what someone is trying to infer.
Alex: That's a better way to hear it. The authors propose a broad progression toward more effortful processing higher in the medial frontal cortex. But emotional information also contributes to interpreting minds, and the subdivisions aren't sealed compartments.
Sam: Moral judgment would seem to make a clean separation even harder. Does it have a distinct network in this review?
Alex: Morality draws together emotion, self–other distinctions, intentions, and social norms. The reviewed connections span those processes rather than identifying a dedicated moral center. In one comparison, anterior and posterior midline regions showed more correlated activity during moral dilemmas than during rest.
Sam: We've heard several comparisons, but no effect sizes or participant totals. How strongly should we trust the overall map?
Alex: The excerpt doesn't provide those numbers for these examples, or a pooled effect estimate. This is a review organizing findings, not a single experiment testing the full map. I'd use it as a conceptual synthesis, not a quantitative ranking of which connection matters most.
Sam: And do the authors agree that the regional boundaries remain uncertain?
Alex: They explicitly identify reproducibility as a lingering issue. Some accounts emphasize the anterior region's role in self–other distinction; others emphasize a lower-to-upper contrast between self and other. The authors call for broader network methods and stimulation studies that could supply causal evidence.
Sam: Given those limits, who should read the full document, and where should they start?
Alex: Researchers linking social cognition to brain networks should read the discussion's sections on the different frontal subdivisions. Pair those with “Measuring Brain Connectivity in the DMN,” especially its warnings about direction and negative correlations. Read it as a 2014 framework whose proposed boundaries need testing, not a settled anatomical atlas.
Sam: And for someone who mainly needs the idea to carry into their own field?
Alex: Understanding another person depends not just on which brain regions respond, but on how they work together.
Sam: Keep the connections in view.