Am J Psychiatry. 2014 Jan;171(1):82-90. doi: 10.1176/appi.ajp.2013.13070852.
Extreme emotional reactivity is a defining feature of borderline personality disorder, yet the neural-behavioral mechanisms underlying this affective instability are poorly understood. One possible contributor is diminished ability to engage the mechanism of emotional habituation. The authors tested this hypothesis by examining behavioral and neural correlates of habituation in borderline patients, healthy comparison subjects, and a psychopathological comparison group of patients with avoidant personality disorder.
During fMRI scanning, borderline patients, healthy subjects, and avoidant personality disorder patients viewed novel and repeated pictures, providing valence ratings at each presentation. Statistical parametric maps of the contrasts of activation during repeated versus novel negative picture viewing were compared between groups. Psychophysiological interaction analysis was employed to examine functional connectivity differences between groups.
Unlike healthy subjects, neither borderline nor avoidant personality disorder patients exhibited increased activity in the dorsal anterior cingulate cortex when viewing repeated versus novel pictures. This lack of an increase in dorsal anterior cingulate activity was associated with greater affective instability in borderline patients. In addition, borderline and avoidant patients exhibited smaller increases in insula-amygdala functional connectivity than healthy subjects and, unlike healthy subjects, did not show habituation in ratings of the emotional intensity of the images. Borderline patients differed from avoidant patients in insula-ventral anterior cingulate functional connectivity during habituation.
Unlike healthy subjects, borderline patients fail to habituate to negative pictures, and they differ from both healthy subjects and avoidant patients in neural activity during habituation. A failure to effectively engage emotional habituation processes may contribute to affective instability in borderline patients.
极端情绪反应是边缘型人格障碍的一个显著特征，但这种情感不稳定的神经行为机制尚未得到充分理解。一个可能的原因是情绪习惯化能力的下降。作者通过检查边缘型人格障碍患者、健康对照组和回避型人格障碍患者的习惯化的行为和神经相关性来检验这一假说。
在 fMRI 扫描期间，边缘型人格障碍患者、健康受试者和回避型人格障碍患者观看新的和重复的图片，并在每次呈现时提供情感评价。在组间比较重复与新的负面图片观看时激活的对比的统计参数映射。采用心理生理交互分析来检查组间功能连接的差异。
与健康受试者不同，边缘型或回避型人格障碍患者在观看重复与新的图片时，背侧前扣带皮层的活动没有增加。这种背侧前扣带皮层活动的增加缺失与边缘型患者的情感不稳定有关。此外，边缘型和回避型患者的岛叶-杏仁核功能连接增加幅度小于健康受试者，而且与健康受试者不同，他们对图像情绪强度的评价没有习惯化。在习惯化过程中，边缘型患者与回避型患者的岛叶-腹侧前扣带功能连接不同。
与健康受试者不同，边缘型人格障碍患者不能对负面图片产生习惯化，而且在习惯化过程中的神经活动与健康受试者和回避型人格障碍患者都不同。不能有效地参与情绪习惯化过程可能是边缘型人格障碍患者情感不稳定的原因之一。
