Price C J, Moore C J, Frackowiak R S
Wellcome Department of Cognitive Neurology, Institute of Neurology, London, United Kingdom.
Neuroimage. 1996 Feb;3(1):40-52. doi: 10.1006/nimg.1996.0005.
The effect of the presentation rate and exposure duration of visually presented words on brain activity was investigated using positron emission tomography. Subjects either read aloud or silently mouthed the names of words. In regions associated with early visual analysis, activity increased with both rate and duration; in regions associated with response generation, activity increased with increasing rate but was unaffected by duration; and in regions associated with word recognition, activity decreased with increasing duration. The variable responses of different brain regions illustrate the functional segregation of these regions. Of particular interest was the dissociation between activity in the posterior fusiform gyri and that in the medial lingual gyrus--in the former, activity increased with rate and duration but the latter was unaffected by either variable. This finding suggests that word processing in the lingual gyrus during reading is distinct from that in the posterior fusiform gyri. A further observation was that during reading aloud, when subjects can hear the sound of their own voice, the response in the primary auditory cortices increased with stimulus rate, demonstrating that subjects process the sound of their own voice in a qualitatively similar way to words spoken by another.
利用正电子发射断层扫描技术，研究了视觉呈现单词的呈现速率和暴露持续时间对大脑活动的影响。受试者要么大声朗读单词的名称，要么不出声地默读。在与早期视觉分析相关的区域，活动随速率和持续时间的增加而增强；在与反应生成相关的区域，活动随速率增加而增强，但不受持续时间影响；在与单词识别相关的区域，活动随持续时间增加而减弱。不同脑区的可变反应说明了这些区域的功能分离。特别有趣的是梭状回后部和舌回中部活动的分离——在前者中，活动随速率和持续时间增加，但后者不受任何一个变量的影响。这一发现表明，阅读过程中舌回的单词处理与梭状回后部不同。进一步的观察结果是，在大声朗读时，当受试者能听到自己的声音时，初级听觉皮层的反应随刺激速率增加，这表明受试者处理自己声音的方式与处理他人所说单词的方式在性质上相似。
