Time course of perception in facial expression of emotion in Borderline Personality Disorder (BPD): a Magnetoencephalographic (MEG) study

Background: Facial expression recognition appears impaired in BPD. Temporal electrophysiological response can be measured by magnetoencephalographic (MEG) means that contain a face-specific event-related magnetic field that peaks around 170ms. We investigated if amplitudes are modulated by emotions in BPD compared to controls. Methods: MEG war recorded in 14 BPD inpatients and 13 controls using a 93-channel MEG system by Eagle-Technology. First, subjects had to quietly observe a random sequence of objects and Ekman's „pictures of facial affect“. Secondly, Ekman faces that each displayed one of the six basic emotions and neutral faces were selected which subjects had to categorize in a 2-alternatives-forced choice task. Alexythymia was assessed using the Toronto-Alexythymia-Scale-26. Results: There was a higher error rate in emotional expression recognition over all emotions in patients (p<0.05); for the emotion fear a „hypersensitivity“ in BPD patients occurred with them showing significantly less errors. TAS-26 total scores were higher in patients than controls (p<0.001). There was no significant difference in response time between groups(p=0.626).We observed an early face-selective M100 response. In a comparison between neutral and negative facial expression BPD showed an effect which started about 100ms poststimulus. Discussion: This is in line with ERP studies and might implicate early amygdala driven influence on visual perception of emotional salient stimuli in BPD.