Fine Neural Tuning for Orthographic Properties of Words Emerges Early in Children Reading Alphabetic Script

Abstract

The left-lateralized N170 component of ERPs for words compared with various control stimuli is considered as an electrophysiological manifestation of visual expertise for written words. To understand the information sensitivity of the effect, researchers distinguish between coarse tuning for words (the N170 amplitude difference between words and symbol strings) and fine tuning for words (the N170 amplitude difference between words and consonant strings). Earlier developmental ERP studies demonstrated that the coarse tuning for words occurred early in children (8 years old), whereas the fine tuning for words emerged much later (10 years old). Given that there are large individual differences in reading ability in young children, these tuning effects may emerge earlier than expected in some children. This study measured N170 responses to words and control stimuli in a large group of 7-year-olds that varied widely in reading ability. In both low and high reading ability groups, we observed the coarse neural tuning for words. More interestingly, we found that a stronger N170 for words than consonant strings emerged in children with high but not low reading ability. Our study demonstrates for the first time that fine neural tuning for orthographic properties of words can be observed in young children with high reading ability, suggesting that the emergent age of this effect is much earlier than previously assumed. The modulation of this effect by reading ability suggests that fine tuning is flexible and highly related to experience. Moreover, we found a correlation between this tuning effect at left occipitotemporal electrodes and children's reading ability, suggesting that the fine tuning might be a biomarker of reading skills at the very beginning of learning to read. To understand the information sensitivity of the effect, researchers distinguish between coarse tuning for words (the N170 amplitude difference between words and symbol strings) and fine tuning for words (the N170 amplitude difference between words and consonant strings). Earlier developmental ERP studies demonstrated that the coarse tuning for words occurred early in children (8 years old), whereas the fine tuning for words emerged much later (10 years old). Given that there are large individual differences in reading ability in young children, these tuning effects may emerge earlier than expected in some children. This study measured N170 responses to words and control stimuli in a large group of 7-year-olds that varied widely in reading ability. In both low and high reading ability groups, we observed the coarse neural tuning for words. More interestingly, we found that a stronger N170 for words than consonant strings emerged in children with high but not low reading ability. Our study demonstrates for the first time that fine neural tuning for orthographic properties of words can be observed in young children with high reading ability, suggesting that the emergent age of this effect is much earlier than previously assumed. The modulatio...

Sensitivity to Stroke Emerges in Kindergartners Reading Chinese Script

“…Results of hierarchical regression analyses showed that Chinese word reading explained significant additional variance in stroke sensitivity after having statistically controlled for age, but age did not explain significant additional variance in stroke sensitivity beyond reading experience. This finding is consistent with previous studies showing that reading experience, rather than age, plays a more important role in learning to read among school-age children (e.g., Burgund et al, 2006; Zhao et al, 2014a). We expected that at an earlier stage of learning to read, e.g., in kindergarten years, maturation should play an equally important role, considering that perception of objects and events in the natural environment is a real-time task and a child needs to have mature sensory primitives (Aslin and Smith, 1988), but finding of the current study did not support this expectation.…”

“…It is the first step of visual-orthographic processing that is crucial for reading and learning to read (Maurer and McCandliss, 2007). Recent electrophysiological studies showed that visual expertise for written words correlates with children’s individual reading ability (Zhao et al, 2014a) and that visual word expertise (written word N1) can be observed in young children who has not received formal reading training (Li et al, 2013). It was also reported that dyslexic children showed reduced N1 tuning for written words (Maurer et al, 2007).…”

“…Burgund et al (2006) found the emergence of letter specific-processing in English is linked to increased reading skill rather than increased age among a group of 6-to-19-year-olds. Zhao et al (2014a) found that fine neural tuning for visual words, which reflects sensitivity to orthographic regularity, emerged in 7-year-old German-speaking children with high but not low reading ability. Li et al (2013) found that neural specialization for word processing is significantly influenced by reading experience (indexed by sight vocabulary) in 5-and 6-year-old Chinese kindergartners.…”

“…Finally, reading ability modulates visual expertise for word processing across orthographies (Burgund et al, 2006; Li et al, 2013; Zhao et al, 2014a; Su et al, 2015). Burgund et al (2006) found the emergence of letter specific-processing in English is linked to increased reading skill rather than increased age among a group of 6-to-19-year-olds.…”

Attention that covers letters is necessary for the left-lateralization of an early print-tuned ERP in Japanese hiragana

“…For example, children who have learned letters but with developing phonological conversion skills show comparable N170 amplitude in both hemispheres (Kast et al, 2010) or bilateral increase in amplitude against visual control stimuli (Maurer et al, 2006;Zhao et al, 2014). In skilled adult readers, the consistency of letterto-sound correspondences has been shown to influence N170 leftlateralization for pseudowords, which was present in transparent German (Maurer et al, 2005b) but absent in opaque English (Maurer et al, 2005a).…”