Borderline personality trait is associated with neural differentiation of self-other processing: A functional near-infrared spectroscopy study.

ABSTRACT

BACKGROUND: Individuals with borderline personality traits are known to have disturbed representations of self and others. Specifically, an unstable self-identity and difficulties distinguishing between self and others can impair their mentalizing abilities in interpersonal situations. However, it is unclear whether these traits are linked to differences in neural representation of self and others. METHODS: In this study involving 156 young adults, changes in neural function during self-other processing were measured using a Functional Near-Infrared Spectroscopy (fNIRS) task and a self-report survey. During the fNIRS task, participants were asked about their own traits, others' traits, how they believed others perceived them, and the basic meaning of words. The study aimed to determine whether the degree of neural differentiation between the task conditions was related to borderline personality traits. RESULT: The study found that traits indicative of identity instability could be predicted by similarities in task-dependent connectivity. Specifically, the neural patterns when individuals estimated how others perceived them were more similar to the patterns when they judged their own traits. CONCLUSIONS: These findings suggest that borderline personality traits related to identity issues may reflect difficulties in distinguishing between neural patterns when processing self and other information.