Phonological decoding involves left posterior fusiform gyrus
Phonological decoding involves left posterior fusiform gyrus
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DOI：
10.1002/hbm.20122
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发表时间：
2005-10-01
影响因子：
4.8
通讯作者：
Eden, GF
中科院分区：
文献类型：
--
作者：
Dietz, NAE;Jones, KM;Eden, GF
朗读新单词是通过音系解码来实现的，在这个过程中，应用字素到音素的转换规则来“读出”单词的口语表示。许多脑成像研究通过对比伪词（可发音的非词）与真实单词的阅读来检查语音解码的神经基础。然而，只有少数研究考察了大声和无声条件下的伪词阅读，以及可能显着改变语音解码的功能解剖的任务参数。受试者参加了一项功能磁共振成像研究，内容包括大声假词、大声真词、无声假词和无声真词阅读。使用这种二乘二的设计，我们检查了词类型（真实词与伪词）和响应模式（无声与大声）的影响及其相互作用。我们发现（1）四个区域在四种阅读条件下始终保持活跃：左中央前回的前部（布罗德曼区（BA）6）和左腹侧枕颞皮质内的三个区域； （2）左额下回和左顶内沟的词型（伪词>词）主效应； (3) 反应模式（大声 > 无声）的主要影响，包括双侧运动、听觉和纹状外皮层； 4）单个左半球纹外区域通过响应模态交互效应显示词类型。该区域位于 BA 19 的后梭状皮层内，受到不同语音处理需求的独特调节。这一结果表明，阅读时，单词形式在首次被识别为字母刺激时会受到语音分析，而 BA 19 参与处理单词的语音属性。
Aloud reading of novel words is achieved by phonological decoding, a process in which grapheme-to-phoneme conversion rules are applied to "sound out" a word's spoken representation. Numerous brain imaging studies have examined the neural bases of phonological decoding by contrasting pseudoword (pronounceable nonwords) to real word reading. However, only a few investigations have examined pseudoword reading under both aloud and silent conditions, task parameters that are likely to significantly alter the functional anatomy of phonological decoding. Subjects participated in an fMRI study of aloud pseudoword, aloud real word, silent pseudoword, and silent real word reading. Using this two-by-two design, we examined effects of word-type (real words vs. pseudowords) and response-modality (silent vs. aloud) and their interactions. We found (1) four regions to be invariantly active across the four reading conditions: the anterior aspect of the left precentral gyrus (Brodmann's Area (BA) 6), and three areas within the left ventral occipitotemporal cortex; (2) a main effect of word-type (pseudowords > words) in left inferior frontal gyrus and left intraparietal sulcus; (3) a main effect of response-modality (aloud > silent) that included bilateral motor, auditory, and extrastriate cortex; and 4) a single left hemisphere extrastriate region showing a word-type by response-modality interaction effect. This region, within the posterior fusiform cortex at BA 19, was uniquely modulated by varying phonological processing demands. This result suggests that when reading, word forms ate subject to phonological analysis at the point they are first recognized as alphabetic stimuli and BA 19 is involved in processing the phonological properties of words.