Early Phonological Neural Specialization Predicts Later Growth in Word Reading Skills

Abstract

According to the Interactive Specialization Theory, cognitive skill development is facilitated by a process of neural specialization. In line with this theory, the current study investigated whether neural specialization for phonological and semantic processing at 5-to-6 years old was predictive of growth in word reading skills from 5-to-8 years old. Specifically, four regression models were estimated in which reading growth was predicted from: (1) an intercept-only model, (2) measures of semantic and phonological neural specialization, (3) performance on semantic and phonological behavioral tasks, or (4) a combination of neural specialization and behavioral performance. Results from the preregistered analyses revealed little evidence in favor of the hypothesis that early semantic and phonological skills predict growth in reading. However, results from the exploratory analyses, which included a larger sample, focused exclusively on the phonological predictors, and investigated relative growth in reading, demonstrated strong evidence that variability in phonological processing is predictive of growth in word reading skills. Specifically, the best fitting model included both measures of phonological neural specialization within the posterior superior temporal gyrus and performance on a phonological behavioral task. This work provides important preliminary evidence in favor of the Interactive Specialization Theory and, more specifically, for the role of phonological neural specialization in the development of early word reading skills.

Neural pathways of phonological and semantic processing and its relations to children’s reading skills

“…In the pre-registered analyses, we related functional connectivity during all lexical conditions with standardized measures of reading. Contrary to the prior literature showing moderate to strong associations between phonological brain systems and word reading skills (e.g., Jasinska et al, 2020;Wang et al, 2013;Wang et al, 2020Yamasaki et al, 2021;Yu et al, 2018), we only found weak (and statistically unreliable) correlations between connectivity in the dorsal pathway and children's word reading skills. To our surprise, this weak correlation was also evident in our first exploratory analyses which examined connectivity using a task contrast of targeted conditions, (O+P+ & O-P-) > fixation for the rhyming task and (strongly related & unrelated) > fixation for the semantic task.…”

“…Phonological specialization in the left STG is evident in children by age five (e.g., Mathur et al, 2020;Weiss, Cweigenberg, & Booth, 2018;Yamasaki et al, 2021), whereas specialization in the dorsal IFG is thought to develop later around age seven (e.g., Wang, Yamasaki, Weiss, & Booth, 2021;Yamasaki et al, 2021). Notably, the engagement of this dorsal fronto-temporal pathway during phonological processing is predictive of children's word reading skills throughout reading development (Wang et al, 2013).…”

Language input in late infancy scaffolds emergent literacy skills and predicts reading related white matter development

“…Further, letter name and sound knowledge at 5-years correlated with estimated myelin density in the left arcuate and the left and right ILF at 26-months. These results extend previous studies indicating that brain structure and function in the left dorsal pathways in 5-year-olds predict later reading skills including letter-word identification (Wang et al, 2020;Yamasaki et al, 2021), phonological awareness (Yu et al, 2018), cross-modal audio-visual processing Booth, 2014, 2015), and word and pseudoword reading (Van Der Auwera et al, 2021). The current study indicates similar correlations between earlier left dorsal white matter structure and 5-yearolds' letter names and sound knowledge, suggesting that these relations already exist in toddlers, long before the onset of reading instruction, and support reading acquisition.…”

“…The left AF and SLF have previously been found to be related to the development of expressive and receptive language skills (O'Muircheartaigh et al, 2014;Deoni et al, 2016;Salvan et al, 2017;Swanson et al, 2017;Romeo et al, 2018aRomeo et al, , 2021Girault et al, 2019b;Sket et al, 2019), and emergent literacy skills (Lebel and Beaulieu, 2009;Yeatman et al, 2011;Saygin et al, 2013;Yu et al, 2018;Wang et al, 2020;Van Der Auwera et al, 2021;Yamasaki et al, 2021). Furthermore, previous studies have shown that the left AF correlates with parent-child conversational turns in 4-6year-olds (Romeo et al, 2018a(Romeo et al, ,b, 2021, and that left dorsal activation and plasticity mediate the relations between parentchild conversational turns and comprehensive language skills (Romeo et al, 2018a).…”

“…Longitudinal studies measuring brain function in children from the pre-reading stage throughout reading development have shown that activation in the left posterior superior temporal gyrus and functional connectivity between the left dorsal and ventral pathways, which is related to phonological processing in pre-readers, predict reading skills 1-3 years later at school-age (Yu et al, 2018;Wang et al, 2020;Yamasaki et al, 2021). Similarly, longitudinal studies that measured brain structure in children from the pre-reading stage throughout reading development consistently demonstrate that throughout development the left AF relates to phonological awareness skills that are essential for reading acquisition (Lebel and Beaulieu, 2009;Yeatman et al, 2011;Saygin et al, 2013;Van Der Auwera et al, 2021).…”