Impulsivity is a characteristic syndromal and neurobehavioral feature of borderline personality disorder (BPD). Research suggests an important interaction between high negative emotions and low behavioral inhibition in BPD. However, knowledge about the generalizability across stimulus categories and diagnosis specificity is limited. We investigated neural correlates of hypothesized impaired response inhibition of BPD patients to negative, positive and erotic stimuli, by comparing them to non-patients and cluster-C personality disorder patients. During fMRI scanning, 53 BPD patients, 34 non-patients and 20 cluster-C personality disorder patients completed an affective go/no-go task, including social pictures. BPD patients showed more omission errors than non-patients, independent of the stimulus category. Furthermore, BPD patients showed higher activity in the inferior parietal lobule and frontal eye fields when inhibiting negative versus neutral stimuli. Activity of the inferior parietal lobule correlated positively with the BPD checklist subscale impulsivity. When inhibiting emotional stimuli, BPD patients showed an altered brain activity in the inferior parietal lobe and frontal eye fields, whereas previously shown dysfunctional prefrontal activity was not replicated. BPD patients showed a general responsivity across stimulus categories in the frontal eye fields, whereas effects in the inferior parietal lobe were specific for negative stimuli. Results of diagnosis specificity support a dimensional rather than a categorical differentiation between BPD and cluster-C patients during inhibition of social emotional stimuli. Supported by behavioral results, BPD patients showed no deficiencies in emotionally modulated response inhibition per se but the present findings rather hint at attentional difficulties for emotional information.
Keywords: BPD; Emotion; Impulsivity; Neuroimaging; Response inhibition.