Karipidis Iliana I, Pleisch Georgette, Di Pietro Sarah V, Fraga-González Gorka, Brem Silvia
Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich, University of Zurich, Zurich, Switzerland.
Center for Interdisciplinary Brain Sciences Research, Stanford University School of Medicine, Stanford, CA, United States.
Front Psychol. 2021 Nov 16;12:750491. doi: 10.3389/fpsyg.2021.750491. eCollection 2021.
Reading acquisition in alphabetic languages starts with learning the associations between speech sounds and letters. This learning process is related to crucial developmental changes of brain regions that serve visual, auditory, multisensory integration, and higher cognitive processes. Here, we studied the development of audiovisual processing and integration of letter-speech sound pairs with an audiovisual target detection functional MRI paradigm. Using a longitudinal approach, we tested children with varying reading outcomes before the start of reading acquisition (T1, 6.5 yo), in first grade (T2, 7.5 yo), and in second grade (T3, 8.5 yo). Early audiovisual integration effects were characterized by higher activation for incongruent than congruent letter-speech sound pairs in the inferior frontal gyrus and ventral occipitotemporal cortex. Audiovisual processing in the left superior temporal gyrus significantly increased from the prereading (T1) to early reading stages (T2, T3). Region of interest analyses revealed that activation in left superior temporal gyrus (STG), inferior frontal gyrus and ventral occipitotemporal cortex increased in children with typical reading fluency skills, while poor readers did not show the same development in these regions. The incongruency effect bilaterally in parts of the STG and insular cortex at T1 was significantly associated with reading fluency skills at T3. These findings provide new insights into the development of the brain circuitry involved in audiovisual processing of letters, the building blocks of words, and reveal early markers of audiovisual integration that may be predictive of reading outcomes.
字母语言的阅读习得始于学习语音和字母之间的关联。这一学习过程与大脑区域的关键发育变化有关，这些大脑区域负责视觉、听觉、多感官整合以及更高层次的认知过程。在此，我们使用视听目标检测功能磁共振成像范式研究了字母 - 语音对的视听处理与整合的发展。采用纵向研究方法，我们在阅读习得开始前（T1，6.5岁）、一年级（T2，7.5岁）和二年级（T3，8.5岁）对阅读结果不同的儿童进行了测试。早期视听整合效应的特征是，在额下回和枕颞叶腹侧皮质中，不一致的字母 - 语音对比一致的字母 - 语音对具有更高的激活。从阅读前阶段（T1）到早期阅读阶段（T2、T3），左侧颞上回的视听处理显著增加。感兴趣区域分析显示，具有典型阅读流畅技能的儿童，其左侧颞上回（STG）、额下回和枕颞叶腹侧皮质的激活增加，而阅读能力差的儿童在这些区域没有表现出相同的发展。T1时双侧STG和岛叶皮质部分区域的不一致效应与T3时的阅读流畅技能显著相关。这些发现为参与字母视听处理（单词的组成部分）的大脑回路的发展提供了新的见解，并揭示了可能预测阅读结果的视听整合早期指标。
