Borderline personality disorder: impaired visual perception and working memory.

The neurobiology of borderline personality disorder (BPD) is still elusive. There are a few studies on neuropsychological performance in BPD, which report a broad spectrum of abnormalities. The present study evaluates perception and working memory as instances of basic cognitive functions. Female subjects diagnosed with DSM-IV borderline personality disorder (n=22) were compared with age- and education-matched controls (n=25). Perception speed was assessed by a backward masking paradigm. Working memory was tested by a series of delayed matching-to-sample paradigms involving varying subsidiary functions like mental rotation, retrieval from memory, ignoring distracters, and cross-modal performance. In backward masking, BPD subjects required significantly longer stimulus onset asynchrony (SOA) than controls to identify the visual target, and there was an additional slowing of the motor response. Working memory accuracy was impaired in BPD subjects, but did not worsen when the cognitive load was increased. With increasing task difficulty, they traded off speed for accuracy similarly as the controls. Impulsivity and dissociation ratings were not correlated with performance. It is concluded that perceptional speed and working memory are impaired in BPD, but that the deficits are not augmented by increasing cognitive load.