Social mind at rest: resting-state connectivity associated with social thought relates to friendship quality.

Although mind wandering is often associated with adverse outcomes, certain thought content may support adaptive functions. This study investigated how latent dimensions of resting-state thought relate to adaptive functioning, mental, emotional, and behavioral problems, and resting-state connectivity patterns in 130 healthy adults. Exploratory factor analysis of the New York Cognition Questionnaire identified seven thought dimensions: five content-related factors (Social Cognition, Self-Oriented Reflection, Interpersonal Reflection, Near-Term Past/Future, and Positive & Meaningful) and two form-related factors (Specificity and Imagery). This is partially consistent with prior work, especially for the social dimension. Controlling for sex and age, partial Pearson correlations showed that Social Cognition and Interpersonal Reflection were positively associated with friendship quality. Vertex-wise analyses identified multiple cortical clusters linked to distinct thought dimensions, and network-based statistics revealed that Social Cognition was associated with resting-state functional connectivity (rsFC) primarily between the default mode and ventral attention networks. Notably, both positive and negative rsFC network strengths related to Social Cognition were associated with friendship quality. These findings collectively support the content regulation hypothesis, suggesting that specific thought dimensions engage distinct neural networks and relate to meaningful social outcomes. Overall, the results highlight the importance of integrating subjective phenomenological experience with objective neural measures.