Idiosyncratic Event Segmentation as a Neural Marker of Loneliness

Loneliness negatively affects both mental and physical health, yet the cognitive mechanisms that give rise to feelings of social disconnection remain poorly understood. A hallmark of loneliness is the feeling of being “out of sync” with others. What contributes to these feelings of misalignment with others? Using functional MRI data from two independent datasets (N = 65 and N = 43), in which participants watched naturalistic videos while their brain activity was recorded, we tested whether lonely individuals display atypical event segmentation patterns—a core component of human perception that shapes how people structure, remember, and understand continuous experiences. Using a Hidden Markov Model–based approach, we found that while non-lonely individuals exhibited similarity, lonely individuals’ neural event segmentation patterns were dissimilar to others, particularly in high-order brain regions (e.g., the default mode network). These findings suggest that loneliness is linked to unique neural organizations of continuous experiences, revealing a potential cognitive mechanism through which loneliness is characterized by divergent structuring of experience.