Emotion dysregulation, characterized by heightened emotional arousal and increased emotional sensitivity, is a core feature of borderline personality disorder (BPD). Although current theories emphasize the disruptive potential of negative emotions on cognitive functioning in BPD, behavioral and neurobiological data on this relationship are still lacking.

Using functional magnetic resonance imaging (fMRI), neural activity was investigated in 22 unmedicated BPD patients and 22 healthy participants (matched for age, education and intelligence) performing an adapted Sternberg working memory task, while being distracted by emotional (negatively arousing) and neutral pictures from the International Affective Picture System (IAPS).

Emotional distraction was associated with significantly higher activation in the amygdala and decreased activation in the dorsolateral prefrontal cortex (DLPFC), extending findings of previous studies in healthy individuals. Patients with BPD showed significantly longer reaction times (RTs) along with significantly higher activation in the amygdala and insula during emotional distraction compared to healthy participants, suggesting that they were more distracted by emotional pictures during the working memory task. Moreover, in the group of BPD patients, a significant negative correlation was found between activation in limbic brain regions and self-reports of current dissociative states.

Our findings suggest hyper-responsiveness to emotionally distracting pictures in BPD patients that negatively affects working memory performance. This stresses the importance of emotion dysregulation in the context of cognitive functioning. Moreover, our findings suggest that dissociative states have a dampening effect on neural reactivity during emotional challenge in BPD.