Kano Michiko, Fukudo Shin, Gyoba Jiro, Kamachi Miyuki, Tagawa Masaaki, Mochizuki Hideki, Itoh Masatoshi, Hongo Michio, Yanai Kazuhiko
Department of Pharmacology, Tohoku University School of Medicine, Sendai, Japan.
Brain. 2003 Jun;126(Pt 6):1474-84. doi: 10.1093/brain/awg131.
Alexithymia is a personal trait characterized by a reduced ability to identify and describe one's own feelings and is known to contribute to a variety of physical and behavioural disorders. To elucidate the pathogenesis of stress-related disorders and the normal functions of emotion, it is important to investigate the neurobiology of alexithymia. Although several neurological models of alexithymia have been proposed, there is very little direct evidence for the neural correlates of alexithymia. Using PET, we studied brain activity in subjects with alexithymia when viewing a range of emotional face expressions. Twelve alexithymic and 12 non-alexithymic volunteers (all right-handed males) were selected from 247 applicants on the basis of the 20-item Toronto Alexithymia Scale (TAS-20). Regional cerebral blood flow (rCBF) was measured with H(2)(15)O-PET while the subjects looked at angry, sad and happy faces with varying emotional intensity, as well as neutral faces. Brain response in the subjects with alexithymia significantly differed from that in the subjects without alexithymia. The alexithymics exhibited lower rCBF in the inferior and middle frontal cortex, orbitofrontal cortex, inferior parietal cortex and occipital cortex in the right hemisphere than the non-alexithymics. Additionally, the alexithymics showed higher rCBF in the superior frontal cortex, inferior parietal cortex and cerebellum in the left hemisphere when compared with the non-alexithymics. A covariance analysis revealed that rCBF in the inferior and superior frontal cortex, orbitofrontal cortex and parietal cortex in the right hemisphere correlated negatively with individual TAS-20 scores when viewing angry and sad facial expressions, and that no rCBF correlated positively with TAS-20 scores. Moreover, the anterior cingulate cortex and insula were less activated in the alexithymics' response to angry faces than their response to neutral faces. These results suggest that people with alexithymia process facial expressions differently from people without alexithymia, and that this difference may account for the disorder of affect regulation and consequent peculiar behaviour in people with alexithymia.
述情障碍是一种个人特质，其特征在于识别和描述自身感受的能力降低，并且已知会导致多种身体和行为障碍。为了阐明应激相关障碍的发病机制以及情绪的正常功能，研究述情障碍的神经生物学很重要。尽管已经提出了几种述情障碍的神经学模型，但关于述情障碍神经关联的直接证据非常少。我们使用正电子发射断层扫描（PET）研究了述情障碍患者在观看一系列情绪面部表情时的大脑活动。根据20项多伦多述情障碍量表（TAS-20），从247名申请者中选出了12名述情障碍志愿者和12名非述情障碍志愿者（均为右利手男性）。当受试者观看具有不同情绪强度的愤怒、悲伤和快乐面孔以及中性面孔时，用H(2)(15)O-PET测量局部脑血流量（rCBF）。述情障碍患者的大脑反应与非述情障碍患者的大脑反应显著不同。与非述情障碍患者相比，述情障碍患者右半球的额中下回、眶额皮质、顶下小叶和枕叶皮质的rCBF较低。此外，与非述情障碍患者相比，述情障碍患者左半球的额上回、顶下小叶和小脑的rCBF较高。协方差分析显示，在观看愤怒和悲伤面部表情时右半球的额上回和额中下回、眶额皮质和顶叶皮质的rCBF与个体TAS-20得分呈负相关，且没有rCBF与TAS-20得分呈正相关。此外，与对中性面孔的反应相比，述情障碍患者对愤怒面孔的反应中前扣带回皮质和脑岛的激活较少。这些结果表明，述情障碍患者处理面部表情的方式与非述情障碍患者不同，这种差异可能解释了述情障碍患者的情感调节障碍及随之而来的特殊行为。
