Curtis V A, Bullmore E T, Brammer M J, Wright I C, Williams S C, Morris R G, Sharma T S, Murray R M, McGuire P K
Department of Psychological Medicine, Institute of Psychiatry, London, United Kingdom.
Am J Psychiatry. 1998 Aug;155(8):1056-63. doi: 10.1176/ajp.155.8.1056.
Functional magnetic resonance imaging was used to study changes in cerebral blood oxygenation in schizophrenic patients during a verbal fluency task.
Five right-handed male schizophrenic patients and five volunteers matched on demographic variables and verbal fluency performance participated in the study. Echoplanar images were acquired over 5 minutes at 1.5 T while the subjects performed two tasks. The first involved paced silent generation of words beginning with an aurally presented cue letter. This task alternated with paced silent repetition of the aurally presented word "rest." Generic brain activation maps were constructed from individual images by sinusoidal regression and non-parametric hypothesis testing. Between-group differences in the mean power of experimental response were identified on a voxelwise basis by an analysis of covariance that controlled for between-group differences in stimulus-correlated motion.
The comparison group showed significant responses in the left prefrontal cortex, the insula bilaterally, the midline supplementary motor area, and the medial parietal cortex. Compared to those subjects, the schizophrenic subjects showed significantly reduced power of response in the left dorsal prefrontal cortex, the inferior frontal gyrus, and the insula but significantly increased power of response in the medial parietal cortex. In both groups frontal and parietal responses were negatively correlated.
Schizophrenic patients displayed attenuated power of response in several frontal regions during word generation but greater power of response in the medial parietal cortex during word repetition.
运用功能磁共振成像技术研究精神分裂症患者在言语流畅性任务期间脑血氧合的变化。
五名右利手男性精神分裂症患者和五名在人口统计学变量及言语流畅性表现上相匹配的志愿者参与了该研究。在1.5T磁场下，受试者执行两项任务的同时，在5分钟内采集回波平面图像。第一项任务是根据听觉呈现的提示字母，有节奏地默默生成单词。此任务与有节奏地默默重复听觉呈现的单词“休息”交替进行。通过正弦回归和非参数假设检验，从个体图像构建通用脑激活图。通过控制刺激相关运动的组间差异的协方差分析，在体素水平上确定实验反应平均功率的组间差异。
对照组在左侧前额叶皮质、双侧脑岛、中线辅助运动区和内侧顶叶皮质显示出显著反应。与这些受试者相比，精神分裂症受试者在左侧背侧前额叶皮质、额下回和脑岛的反应功率显著降低，但在内侧顶叶皮质的反应功率显著增加。两组的额叶和顶叶反应均呈负相关。
精神分裂症患者在单词生成过程中，几个额叶区域的反应功率减弱，但在单词重复过程中，内侧顶叶皮质的反应功率增强。
