Brain activation in response to overt and covert fear and happy faces in women with borderline personality disorder

Abstract

Borderline personality disorder (BPD) is a serious condition involving emotion dysregulation. Past research has identified BPD-associated differences within fronto-limbic circuitry during conditions of processing negative emotion. Functional magnetic resonance imaging (fMRI) paradigms that incorporate overt and covert (masked) presentations of emotional stimuli can provide complementary information about neural systems underlying emotion processing (e.g., both slow [overt] and fast [covert; automatic] processing pathways). This study examined brain activation during processing of overt and covert presentations of emotional faces in 12 women with BPD and 12 age-matched healthy controls. To assess a range of emotional valence and arousal, we examined responses to fear, happy and neutral expressions. All participants underwent an fMRI scanning session in which participants passively viewed emotional faces. Scanning sessions consisted of 5 runs including: (1) Overt Fear (OF) versus Neutral (N), (2) Covert Fear (CF) versus Covert Neutral (CN), (3) Overt Happy (OH) versus N, (4) Covert Happy (CH) versus CN, and (5) N versus fixation. We compared whole-brain activation between groups for each run. In response to overt fear, BPD patients showed greater activation both in left amygdala and in several frontal cortical regions. There were no significant differences in brain activation in response to overt happy faces. In response to covert fear and covert happy stimuli, the BPD group also showed greater activation than controls in several regions including frontal and temporal cortical regions, as well as cerebellum and thalamus. These findings add to prior reports suggesting increased amygdala activation in BPD, but we found this only in the overt fear versus fixation condition. In this sample, BPD patients showed hyper-activation, rather than hypo-activation, of cortical regulatory regions during overt fear. Enhanced cortical recruitment in response to covert fear and happy faces in BPD could reflect a more extended response system in which stimuli that typically only activate automatic pathways are additionally tapping into cortical regulatory systems. The observation of this pattern both in response to fear and in response to happy presentations suggests that the effect of arousal may be as or more impactful than the effect of emotional valence.

Keywords: Amygdala; Backward masking; Borderline personality disorder; Covert; Emotion; Overt; fMRI.

Fig. 1

The general design of each fMRI run is shown. Each run consisted of a repeating pattern beginning with a 24 s block of fixation, followed by 24 s of the key emotion (e.g., fear, happy), followed by a 24 s presentation of neutral faces

Fig. 2

Clusters are shown representing the group difference (BPD>controls) for the overt fear>fixation contrast. Cluster locations included the left amygdala/hippocampus, right inferior frontal gyrus (BA 47/11), right medial frontal gyrus (BA9), left middle temporal gyrus, and right superior and middle temporal gyrus. R right

Fig. 3

Clusters are shown representing the group difference (BPD>controls) for the covert fear>fixation contrast. Cluster locations included left superior temporal gyrus and the right inferior parietal lobule/angular gyrus. R right

Fig. 4

Clusters are shown representing the group difference (BPD>controls) for the covert fear>neutral contrast. Cluster locations included left regions of the inferior frontal gyrus (BA 45/46/47), precuneus, and inferior parietal lobule. R right

Fig. 5

Clusters are shown representing the group difference (BPD>controls) for the covert happy>fixation contrast in the left supramarginal gyrus (BA40). R right

Fig. 6

Clusters are shown representing the group difference (BPD>controls) for the covert happy>neutral contrast. BPD patients showed increased activation in several left-sided frontal, subcortical and temporal regions, including the medial (BA9) and middle (BA11) frontal gyrus, thalamus, middle temporal gyrus (BA21) as well as bilateral regions of the superior temporal gyrus/supramarginal gyrus (BA39/40, BA22) and cerebellum. R right