Altered amygdalar emotion space in borderline personality disorder normalizes following dialectical behavioral therapy

Borderline personality disorder (BPD) is a mental health condition characterized by an inability to regulate one’s emotions or accurately process the emotional states of others. Previous neuroimaging studies using classical univariate analyses have tied such emotion dysregulation to aberrant activity levels in the amygdala of patients with BPD. However, multivariate analyses have not yet been utilized to investigate how representational spaces of emotion information may be systematically altered in patients with BPD. To this end, patients performed an emotional face matching task in the MR scanner, before and after a 10-week inpatient program of dialectical behavioral therapy (DBT). Representational similarity analysis of the amygdala revealed a negative bias in the underlying affective space (in that activity patterns evoked by angry, fearful, and neutral faces were more similar to each other than to patterns evoked by surprised faces), which normalized after DBT. This bias-to-normalization effect was present neither in patients’ objective-selective cortex nor in amygdalar activity patterns of a group of healthy volunteers. Such findings suggest a more refined role for the amygdala in the pathological processing of perceived emotions and may provide new diagnostic and prognostic imaging-based markers of emotion dysregulation and personality disorders.