Laboratory of Language Neurobiology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Pasteur 3, Warsaw 02-093, Poland.
Laboratory of Language Neurobiology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Pasteur 3, Warsaw 02-093, Poland.
Neuroimage. 2023 Sep;278:120296. doi: 10.1016/j.neuroimage.2023.120296. Epub 2023 Jul 24.
Learning letter and speech sound (LS) associations is a major step in reading acquisition common for all alphabetic scripts, including Braille used by blind readers. The left superior temporal cortex (STC) plays an important role in audiovisual LS integration in sighted people, but it is still unknown what neural mechanisms are responsible for audiotactile LS integration in blind individuals. Here, we investigated the similarities and differences between LS integration in blind Braille (N = 42, age range: 9-60 y.o.) and sighted print (N = 47, age range: 9-60 y.o.) readers who acquired reading using different sensory modalities. In both groups, the STC responded to both isolated letters and isolated speech sounds, showed enhanced activation when they were presented together, and distinguished between congruent and incongruent letter and speech sound pairs. However, the direction of the congruency effect was different between the groups. Sighted subjects showed higher activity for incongruent LS pairs in the bilateral STC, similarly to previously studied typical readers of transparent orthographies. In the blind, congruent pairs resulted in an increased response in the right STC. These differences may be related to more sequential processing of Braille as compared to print reading. At the same time, behavioral efficiency in LS discrimination decisions and the congruency effect were found to be related to age and reading skill only in sighted participants, suggesting potential differences in the developmental trajectories of LS integration between blind and sighted readers.
学习字母和语音（LS）关联是阅读获取的一个主要步骤，所有的字母表文字都需要经历这一步骤，包括盲人使用的盲文。左上方颞叶皮层（STC）在有视力的人视听 LS 整合中起着重要作用，但目前尚不清楚在盲人中负责视听 LS 整合的神经机制是什么。在这里，我们研究了盲文（N=42，年龄范围：9-60 岁）和有视力的印刷文字（N=47，年龄范围：9-60 岁）读者在 LS 整合方面的异同，他们使用不同的感觉模式来学习阅读。在这两组中，STC 对孤立的字母和孤立的语音都有反应，当它们一起呈现时会增强激活，并且可以区分一致和不一致的字母和语音对。然而，两组的一致性效应的方向不同。有视力的受试者在双侧 STC 中对不一致的 LS 对表现出更高的活动，与之前研究过的透明正字法的典型读者相似。在盲人中，一致的 LS 对会导致右 STC 的反应增加。这些差异可能与盲文阅读相比，印刷阅读的顺序处理更多有关。同时，仅在有视力的参与者中发现 LS 辨别决策的行为效率和一致性效应与年龄和阅读技能相关，这表明盲人和有视力的读者之间的 LS 整合的发展轨迹可能存在差异。
