Article The Neural Correlates of Anomalous Habituation to Negative Emotional Pictures in Borderline and Avoidant Personality Disorder Patients

is a defining feature of borderline person-ality disorder, yet the neural-behavioral mechanisms underlying this affective in-stability are poorly understood. One possi-ble contributor is diminished ability to engage the mechanism of emotional ha-bituation. The authors tested this hypoth-esis by examining behavioral and neural correlates of habituation in borderline patients, healthy comparison subjects, and a psychopathological comparison group of patients with avoidant personal-ity disorder. Method: During fMRI scanning, border-line patients, healthy subjects, and avoi-dant personality disorder patients viewed novel and repeated pictures, providing valence ratings at each presentation. Sta-tistical parametric maps of the contrasts of activation during repeated versus novel negative picture viewing were compared between groups. Psychophysiological in-teraction analysis was employed to exam-ine functional connectivity differences between groups. Results: Unlike healthy subjects, neither borderline nor avoidant personality disor-der patients exhibited increased activity in the dorsal anterior cingulate cortex when viewing repeated versus novel pictures. This lack of an increase in dorsal anterior cingulate activity was associated with greater affective instability in borderline patients. In addition, borderline and avoi-dant patients exhibited smaller increases in insula-amygdala functional connectivity than healthy subjects and, unlike healthy subjects, did not show habituation in ratings of the emotional intensity of the images. Borderline patients differed from avoidant patients in insula-ventral anterior cingulate functional connectivity during habituation. Conclusions: Unlike healthy subjects, bor-derline patients fail to habituate to negative pictures, and they differ from both healthy subjects and avoidant patients in neural activity during habituation. A failure to ef-fectively engage emotional habituation pro-cesses may contribute to affective instability in borderline patients