Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Cereb Cortex. 2012 Dec;22(12):2715-32. doi: 10.1093/cercor/bhr295. Epub 2012 Jan 10.
Regions in left occipitotemporal (OT) cortex, including the putative visual word form area, are among the most commonly activated in imaging studies of single-word reading. It remains unclear whether this part of the brain is more precisely characterized as specialized for words and/or letters or contains more general-use visual regions having properties useful for processing word stimuli, among others. In Analysis 1, we found no evidence of greater activity in left OT regions for words or letter strings relative to other high-spatial frequency high-contrast stimuli, including line drawings and Amharic strings (which constitute the Ethiopian writing system). In Analysis 2, we further investigated processing characteristics of OT cortex potentially useful in reading. Analysis 2 showed that a specific part of OT cortex 1) is responsive to visual feature complexity, measured by the number of strokes forming groups of letters or Amharic strings and 2) processes learned combinations of characters, such as those in words and pseudowords, as groups but does not do so in consonant and Amharic strings. Together, these results indicate that while regions of left OT cortex are not specialized for words, at least part of OT cortex has properties particularly useful for processing words and letters.
左枕颞(OT)皮层的区域,包括假定的视觉单词形式区,是在单字阅读的成像研究中最常被激活的区域之一。目前尚不清楚该大脑区域是否更精确地被描述为专门用于单词和/或字母,或者是否包含更通用的视觉区域,具有处理单词刺激等有用的特性。在分析 1 中,我们没有发现左 OT 区域相对于其他高空间频率高对比度刺激(包括线条图和阿姆哈拉语字符串)对单词或字母串的活动增加的证据,其中包括线条图和阿姆哈拉语字符串(构成埃塞俄比亚书写系统)。在分析 2 中,我们进一步研究了 OT 皮层的潜在有用的阅读处理特征。分析 2 表明,OT 皮层的一个特定区域 1)对由形成字母或阿姆哈拉语字符串的笔画数量测量的视觉特征复杂性有反应,2)以组的形式处理学习的字符组合,如单词和伪词,但不以组的形式处理辅音和阿姆哈拉语字符串。这些结果表明,虽然左 OT 皮层的区域不是专门用于单词的,但至少 OT 皮层的一部分具有特别有助于处理单词和字母的特性。