精神分裂症患者的大脑两半球互抑与互补协同功能障碍

Dysfunction in interhemispheric inhibition and enhancement in patients with schizophrenia

背景此前有研究结果表明精神分裂症患者大脑左右两半球之间的协同功能下降；但临床神经心理研究结果提示大脑两半球的协同活动有互抑与互补两种形式。本研究旨在进一步探讨精神分裂症患者的大脑两半球互抑与互补两种协同功能是否均受损。方法30例精神分裂症患者和28名健康对照纳入研究，采用Stroop字图实验和注意广度实验分别测试大脑两半球的互抑及互补协同功能，用三视野速示法将图形伪随机呈现在左、中、右视野。实验中被试眼睛与电脑屏幕正中注视点保持水平，距离屏幕的距离为57cm。左、右侧视野的图形位置为水平距离正中点3°～6°视角，中间视野图形的位置为正中左右各1．5°视角，所有图形距离屏幕正中水平线上下各1．5°视角。①Stroop字图实验的图形为直径30mm的圆形或边长30mm的正方形，内有一个汉字“方”或“圆”。每次图形呈现的时间为66．7ms，要求被试又快又准地用按鼠标键的方式判断图形是圆形还是方形，计算机自动记录被试在每个图形判断上的正确与否以及反应时。②注意广度实验的图形是边长26mm的方框内散布着2～9个直径1．4mm的黑圆点，每次图形呈现的时间为130ms。要求被试报告图形中黑点的数目，由主试记录被试每次报告的结果。用斯皮尔曼分配法计算每个被试各个视野的注意广度。结果①Stroop字图实验：所有被试字图不一致图形的反应时长于字图一致图形（P〈0．001），中视野错误率高于左视野（P〈0．05）。患者组中视野错误率高于对照组（P〈0．05）。②注意广度实验：所有被试左、右视野的注意广度为中视野的1／2。患者组中视野注意广度较对照组差（P〈0．01），患者组大脑两半球互补协同功能及左半球的协同能力比正常组差（P〈0．05）。结论精神分裂症患者大脑两半球互抑及互补协同功能均受损，患者左半球的互补协同能力下降。

Background The aberrant pattern of interhemispheric cooperation among patients with schizophrenia has been reported in several studies. However, the two major components of interhemispheric cooperation activities including the mutual inhibition and enhancement between the two hemispheres among this group of patients is unclear： Methods Thirty patients with schizophrenia and twenty-eight healthy age-, sex- and education-matched controls were administered, and the mutual inhibition and enhancement between the two hemispheres were examed by a modified picture-word Stroop test and attention span test, using a three-visual-field presentation tachistoscope. Results ① Picture-word Stroop test： In both groups, the reaction time （RT） on the Stroop picture-word congruent figures was significantly longer than that of the Stroop picture-word incongruent figures （ P 〈0. 001 ） ; the error rate of the middle visual field （MVF） was higher than that of the left visual field （LVF） （ P 〈 0. 05）, Between the patients and controls, no significant differences were found on the Combined Stroop Effect （ P 〉 0. 05） ; However, the error rate on the MVF was higher in the patients than in the controls （ P 〈 0. 05）. ② Attention span test： The LVF and right visual field （RVF） attention span for both groups were as much as half of that on MVF. The MVF attention span among the patients was significantly less than that of the controls （ P 〈 0.01 ） ; However, the LVF and RVF attention span in the patients did not differ significantly from that of the controls （ P 〉0. 05）. Interhemispheric enhancement was significantly decreased in the patients compared with the controls （ P 〈0. 05 ）. Conclusions Interhemispheric cooperation including interhemispheric inhibition and enhancement was decreased in the patients with schizophrenia, which may relate to the neuropsychological dysfunction in the patients with schizophrenia.