Letter processing in the visual system: Different activation patterns for single letters and strings
Letter processing in the visual system: Different activation patterns for single letters and strings
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DOI：
10.3758/cabn.5.4.452
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发表时间：
2005-12-01
影响因子：
2.9
通讯作者：
Gauthier, I
中科院分区：
文献类型：
--
作者：
James, KH;James, TW;Gauthier, I
人们会期望一生的字母识别经验会对视觉系统产生重要影响。令人惊讶的是，有限的证据表明，视觉控制刺激对字母有特定的神经反应。我们使用孤立的字符（罗马字母、数字和汉字）和字符串来测量顺序匹配任务期间的大脑激活。我们通过将伪词的响应与字母串的响应进行对比来定位视觉词形区域（VWFA），但该区域没有显示出任何其他字母视觉专业化的迹象。此外，VWFA 后面的左梭形区域对字母串具有选择性，而更靠前的左梭形区域对单个字母表现出选择性。使用大的感兴趣区域和检查个体响应模式的不同分析的结果揭示了字母串的选择性和单个字母的选择性之间的分离。结果表明，阅读体验会在不同的处理水平上微调视觉表征。一个重要的结论是，不能将不可发音的字母串的处理等同于单字母的感知。
One would expect that a lifetime of experience recognizing letters would have an important influence on the visual system. Surprisingly, there is limited evidence of a specific neural response to letters over visual control stimuli. We measured brain activation during a sequential matching task using isolated characters (Roman letters, digits, and Chinese characters) and strings of characters. We localized the visual word form area (VWFA) by contrasting the response to pseudowords against that for letter strings, but this region did not show any other sign of visual specialization for letters. In addition, a left fusiforrn area posterior to the VWFA was selective for letter strings, whereas a more anterior left fusiform region showed selectivity for single letters. The results of different analyses using both large regions of interest and inspections of individual patterns of response reveal a dissociation between selectivity for letter strings and selectivity for single letters. The results suggest that reading experience fine-tunes visual representations at different levels of processing. An important conclusion is that the processing of nonpronounceable letter strings cannot be assumed to be equivalent to single-letter perception.