Instituto Universitário de Lisboa (ISCTE-IUL), Lisboa, Portugal.
Center for Psychology, Faculty of Psychology and Education Sciences, University of Porto, Rua Alfredo Allen, 4200-135, Porto, Portugal.
Brain Struct Funct. 2021 Nov;226(8):2585-2601. doi: 10.1007/s00429-021-02353-1. Epub 2021 Aug 6.
Brain correlates of reading ability have been intensely investigated. Most studies have focused on single-word reading and phonological processing, but the brain basis of reading fluency remains poorly explored to date. Here, in a voxel-based morphometry study with 8-year-old children, we compared fluent readers (n = 18; seven boys) with dysfluent readers with normal IQ (n = 18; six boys) and with low IQ (n = 18; ten boys). Relative to dysfluent readers, fluent readers had larger gray matter volume in the right superior temporal gyrus and the two subgroups of dysfluent readers did not differ from each other, as shown in frequentist and Bayesian analyses. Pairwise comparisons showed that dysfluent readers of normal and low IQ did not differ in core reading regions and that both subgroups had less gray matter volume than fluent readers in occipito-temporal, parieto-temporal and fusiform areas. We also examined gray matter volume in matched subgroups of dysfluent readers differing only in socioeconomic status (SES): lower-SES (n = 14; seven boys) vs. higher-SES (n = 14; seven boys). Higher-SES dysfluent readers had larger gray matter volume in the right angular gyrus than their lower-SES peers, and the volume of this cluster correlated positively with lexico-semantic fluency. Age, sex, IQ, and gray matter volume of the right angular cluster explained 68% of the variance in the reading fluency of higher-SES dysfluent readers. In sum, this study shows that gray matter correlates of dysfluent reading are independent of IQ, and suggests that SES modulates areas sub-serving lexico-semantic processes in dysfluent readers-two findings that may be useful to inform language/reading remediation programs.
阅读能力的大脑相关性一直受到深入研究。大多数研究都集中在单个单词阅读和语音处理上，但迄今为止，阅读流畅性的大脑基础仍未得到充分探索。在这里，我们通过一项针对 8 岁儿童的基于体素的形态学研究，比较了流畅阅读者（n=18；7 名男孩）与非流畅阅读者（n=18；6 名男孩）以及低智商阅读者（n=18；10 名男孩）。与非流畅阅读者相比，流畅阅读者右侧颞上回的灰质体积较大，而两组非流畅阅读者之间没有差异，这在频率主义和贝叶斯分析中均有体现。成对比较显示，正常智商和低智商的非流畅阅读者在核心阅读区域没有差异，而且这两个亚组的灰质体积均少于流畅阅读者的枕颞叶、顶颞叶和梭状回区域。我们还检查了仅在社会经济地位（SES）方面存在差异的非流畅阅读者匹配亚组的灰质体积：低 SES（n=14；7 名男孩）与高 SES（n=14；7 名男孩）。高 SES 的非流畅阅读者右侧角回的灰质体积大于其低 SES 同龄人，并且该区域的体积与词汇语义流畅性呈正相关。年龄、性别、智商和右侧角回簇的灰质体积解释了高 SES 非流畅阅读者阅读流畅性变异的 68%。总之，这项研究表明，非流畅阅读的灰质相关性与智商无关，并表明 SES 调节了非流畅阅读者词汇语义加工的区域——这两个发现可能有助于为语言/阅读矫正计划提供信息。
