Holt Daphne J, Weiss Anthony P, Rauch Scott L, Wright Christopher I, Zalesak Martin, Goff Donald C, Ditman Tali, Welsh Robert C, Heckers Stephan
Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA.
Biol Psychiatry. 2005 May 1;57(9):1011-9. doi: 10.1016/j.biopsych.2005.01.033.
In healthy individuals, the activity of the medial temporal lobe habituates rapidly with the repeated presentation of a stimulus. Using functional magnetic resonance imaging (fMRI), we tested the hypothesis that habituation of the medial temporal lobe is reduced in schizophrenia.
During fMRI scanning, fearful and happy faces were presented repeatedly to healthy control subjects (n =16) and patients with schizophrenia (n =18). Habituation of medial temporal lobe structures was measured by comparing the hemodynamic response occurring during the early and late portions of the presentation of each face.
Control subjects demonstrated significant medial temporal lobe habituation to fearful but not to happy faces. In contrast, patients with schizophrenia did not demonstrate medial temporal lobe habituation in response to fearful or happy faces. In a direct, between-group comparison, right hippocampal habituation to fearful faces was significantly greater in control subjects than in the schizophrenia patients. Also, there were no significant differences between the patients and control subjects in the early medial temporal lobe response to fearful faces, suggesting that attenuated hippocampal habituation in schizophrenia is not associated with a reduction in initial activation.
These findings suggest that there is abnormal modulation of hippocampal responses to fearful faces in schizophrenia.
在健康个体中，内侧颞叶的活动会随着刺激的重复呈现而迅速产生习惯化。我们使用功能磁共振成像（fMRI）来检验精神分裂症患者内侧颞叶习惯化减弱这一假说。
在fMRI扫描过程中，向健康对照受试者（n = 16）和精神分裂症患者（n = 18）反复呈现恐惧和开心的面孔。通过比较每张面孔呈现早期和晚期出现的血液动力学反应来测量内侧颞叶结构的习惯化。
对照受试者表现出内侧颞叶对恐惧面孔有显著的习惯化，但对开心面孔则没有。相比之下，精神分裂症患者对恐惧或开心面孔均未表现出内侧颞叶习惯化。在直接的组间比较中，对照受试者右侧海马对恐惧面孔的习惯化显著大于精神分裂症患者。此外，患者和对照受试者在早期内侧颞叶对恐惧面孔的反应上没有显著差异，这表明精神分裂症中海马习惯化减弱与初始激活的降低无关。
这些发现表明，精神分裂症患者海马对恐惧面孔的反应存在异常调节。
