Somatosensory processing and borderline personality disorder features: a signal detection analysis of proprioception and exteroceptive sensitivity.

Pain perception in borderline personality disorder (BPD) may reflect abnormalities of the sensory-discriminative and/or motivational-affective domains in those patients. Although pain insensitivity has received considerable specific discussion, the likelihood of a generalized dysfunction in the somatosensory systems in BPD has not been explored. Prior BPD research has focused only on the pain submodality of somatosensation. This study assessed other prominent and basic touch and body sense somatosensory submodalities, exteroception and proprioception, respectively. Exteroception and proprioception were measured with two-point discrimination and weight discrimination tasks, respectively. A group of subjects with BPD features (n = 32) was compared with a control group (n = 29), both drawn from a nonclinical population, across objective laboratory measures of somatosensation. Results indicated that individuals with BPD features do not demonstrate generalized somatosensory deficits. Lack of group differences in these two somatosensation submodalities (particularly the exteroceptive sensitivity submodality) is consistent with (but does not prove) a dysfunction in the pain-specific mechanism of sensitivity and perception in BPD, perhaps one that does not disturb the other somatosensory modalities.