Straube Thomas, Kolassa Iris-Tatjana, Glauer Madlen, Mentzel Hans-Joachim, Miltner Wolfgang H R
Department of Biological and Clinical Psychology, Friedrich-Schiller-University, Am Steiger 3/1, D-07743 Jena, Germany.
Biol Psychiatry. 2004 Dec 15;56(12):921-30. doi: 10.1016/j.biopsych.2004.09.024.
The aim of this study was to identify brain activation to socially threatening stimuli in social phobic subjects during different experimental conditions.
With event-related functional magnetic resonance imaging, brain activation to photographs and schematic pictures depicting angry or neutral facial expressions was measured in social phobic subjects and healthy control subjects, while subjects assessed either emotional expression (angry vs. neutral; explicit task) or picture type (photographic vs. schematic; implicit task).
Compared with control subjects, phobics showed greater responses to angry than to neutral photographic faces in the insula regardless of task, whereas amygdala, parahippocampal gyrus, and extrastriate visual cortex were more strongly activated only during the implicit task. Phobics, in contrast to control subjects, showed similar activation patterns during both tasks. For schematic angry versus neutral faces, activation of insula and extrastriate visual cortex was found in phobics, but not in control subjects, during both tasks.
Differences between social phobics and control subjects in brain responses to socially threatening faces are most pronounced when facial expression is task-irrelevant. Phobics intensively process angry (photographic as well as schematic) facial expressions, regardless of whether this is required. The insula plays a unique role in the processing of threat signals by social phobics.
本研究旨在确定社交恐惧症患者在不同实验条件下对社会威胁性刺激的大脑激活情况。
采用事件相关功能磁共振成像技术，测量社交恐惧症患者和健康对照者对描绘愤怒或中性面部表情的照片和示意图片的大脑激活情况，同时让受试者评估情绪表达（愤怒与中性；显性任务）或图片类型（照片与示意；隐性任务）。
与对照者相比，无论任务如何，恐惧症患者在脑岛对愤怒照片面孔的反应比对中性照片面孔的反应更大，而杏仁核、海马旁回和纹外视觉皮层仅在隐性任务期间激活更强。与对照者不同，恐惧症患者在两项任务期间表现出相似的激活模式。对于示意性愤怒与中性面孔，在两项任务期间，恐惧症患者的脑岛和纹外视觉皮层有激活，而对照者没有。
当面部表情与任务无关时，社交恐惧症患者和对照者在对社会威胁性面孔的大脑反应上的差异最为明显。恐惧症患者会强烈处理愤怒（照片和示意性）面部表情，无论是否需要这样做。脑岛在社交恐惧症患者处理威胁信号中起独特作用。
