Bitan Tali, Weiss Yael, Katzir Tami, Truzman Tammar
Department of Psychology and IIPDM, University of Haifa, Haifa, Israel; Department of Speech Language Pathology, University of Toronto, Toronto, Canada.
Institute for Learning & Brain Sciences, University of Washington, Seattle, WA, USA.
Cortex. 2020 Sep;130:172-191. doi: 10.1016/j.cortex.2020.05.014. Epub 2020 Jun 15.
The current study examined the widely held, but un-tested, assumption that morphological decomposition can compensate for missing phonological information in reading opaque orthographies. In addition, we tested whether morphological decomposition can compensate for the phonological decoding deficits in readers with dyslexia. Hebrew provides a unique opportunity to test these questions as it has a rich Semitic morphology, and two versions of script: a transparent orthography (with diacritic marks, 'pointed') and an opaque orthography (without diacritic marks, 'un-pointed'). In two experiments, one behavioral and one fMRI, skilled and dyslexic readers read aloud Hebrew nouns: half bi-morphemic (root + pattern) and half mono-morphemic (non-decomposable). Each word was presented both in the transparent orthography (pointed), and in the opaque orthography (un-pointed). While skilled readers were faster, and showed no effects of diacritics or morphology, dyslexic readers read pointed words more slowly than un-pointed words and bi-morphemic words faster than mono-morphemic words. The imaging results showed: 1) In both groups a morphological effect was found in un-pointed words, in left inferior and middle frontal gyri, associated with morpho-phonological decomposition. 2) Only readers with dyslexia showed a morphological effect in pointed words in the left occipito-temporal cortex, associated with orthographic processing. 3) Dyslexic readers also showed a positive association between morphological awareness and activation in the left occipito-temporal cortex during reading of all words, and activation in inferior frontal cortex during reading of un-pointed bi-morphemic words. Altogether, these findings suggest that in both typical and dyslexic readers morphological decomposition can compensate for the missing phonological information in an opaque orthography. The results also show that readers with dyslexia can rely on morphological decomposition to compensate for their deficits in phonological decoding. Finally, these results highlight the way in which unique language specific properties shape the neural mechanisms underlying typical and atypical reading.
当前的研究检验了一个被广泛认可但未经检验的假设，即形态分解可以弥补阅读不透明正字法时缺失的语音信息。此外，我们还测试了形态分解是否能够弥补诵读困难读者的语音解码缺陷。希伯来语为检验这些问题提供了一个独特的机会，因为它具有丰富的闪米特语形态，并且有两种书写形式：一种是透明正字法（带有变音符号，“有标点的”）和一种不透明正字法（没有变音符号，“无标点的”）。在两个实验中，一个是行为实验，一个是功能磁共振成像实验，熟练读者和诵读困难读者大声朗读希伯来语名词：一半是双语素的（词根 + 词型），一半是单语素的（不可分解的）。每个单词都以透明正字法（有标点的）和不透明正字法（无标点的）呈现。虽然熟练读者速度更快，并且没有表现出变音符号或形态的影响，但诵读困难读者读有标点的单词比无标点的单词更慢，读双语素单词比单语素单词更快。成像结果显示：1）在两组中，在无标点的单词中发现了形态效应，位于左额下回和额中回，与形态语音分解有关。2）只有诵读困难读者在有标点的单词中在左枕颞叶皮层表现出形态效应，与正字法加工有关。3）诵读困难读者在阅读所有单词时，形态意识与左枕颞叶皮层的激活之间也表现出正相关，在阅读无标点的双语素单词时与额下回皮层的激活之间也表现出正相关。总之，这些发现表明，在典型读者和诵读困难读者中，形态分解都可以弥补不透明正字法中缺失的语音信息。结果还表明，诵读困难读者可以依靠形态分解来弥补他们在语音解码方面的缺陷。最后，这些结果突出了独特的语言特定属性塑造典型和非典型阅读背后神经机制的方式。
