出声阅读条件下不规则汉字频率效应的功能磁共振成像研究

目的利用事件相关功能磁共振成像技术观察出声阅读条件下不规则汉字频率效应的脑激活模式.方法 8名非语言专业大学生在MR扫描过程中执行汉字出声阅读任务.用视觉方式随机呈现40个形声字,其中高频、低频不规则字各20个.结果左侧额中回、左侧额下回、辅助运动区、左侧颞下回后部、双侧纹外皮层、左侧岛叶、扣带回前部表现出频率效应,即阅读低频汉字时的激活强于高频汉字.结论出声阅读汉字特别是低频不规则汉字可激活主要语言加工区,可作为可靠而实用的临床诊断试验.扣带回前部与左侧额中回可能是汉字阅读的特殊脑区.

Frequency effect in reading aloud irregular Chinese characters: an fMRI study

Objective To characterize brain activation associated with the effects of frequency in reading aloud of Chinese characters using event-related functional magnetic resonance imaging. Methods Eight university students were instructed to overtly read visually presented Chinese characters while being scanned with a 1.5 T MRI Siemens scanner. Twenty high and twenty low frequency irregular characters were used. Results Frequency effect was observed in the left middle frontal gyrus, left inferior frontal gyrus, supplementary motor area, left posterior temporal gyrus, left insula, anterior cingulate cortex, and bilateral extrastriate areas. Activation in these regions was significantly stronger during reading low frequency irregular characters than reading high frequency irregular characters. Conclusion Overtly reading Chinese characters, particularly low frequency irregular characters, can reliably elicit most language regions. This task thus is feasible for clinical usage. Anterior cingulated cortex and left middle frontal lobe appear to be specifically related to reading of Chinese characters.