Response inhibition in borderline personality disorder: neural and behavioral correlates.

Although response inhibition is thought to be important in borderline personality disorder (BPD), little is known about its neurophysiological basis. This study aimed to provide insight into this issue by capitalizaing on the the high temporal resolution of electroencephalography and information provided by source localization methods. To this end, twenty unmedicated patients with BPD and 20 healthy control subjects performed a modified go/no-go task designed to better isolate the brain activity specifically associated with response inhibition. Event-related potentials (ERP) were measured and further analyzed at the scalp and source levels. Patients with BPD made more commission errors (failed inhibitions) than control subjects. Scalp ERP data showed that both groups displayed greater frontocentral P3 amplitude for no-go (response inhbition) than for go trials (response execution). However, source reconstruction data revealed that patients with BPD activated posterior parietal regions (precuneus) to inhibit their responses, whereas controls activated prefrontal regions (presupplementary motor area, preSMA). This dissociation was supported by a significant Region (precuneus, preSMA) x Trial Type (no-go, go) x Group (BPD, control) interaction. These findings extend our understanding of the neurophysiological basis of abnormal response inhibition in BPD, suggesting that patients with BPD recruit different brain regions for inhibiting prepotent responses compared to controls. Future research in larger, medication-naïve samples of patients with BPD is required to confirm and extend these findings.