Abstract
The developmental course of neural tuning to visual letter strings is unclear. Here we tested 39 children longitudinally, at the beginning of grade 1 (6.45 ± 0.33 years old) and 1 year after, with fast periodic visual stimulation in electroencephalography to assess the evolution of selective neural responses to letter strings and their relationship with emerging reading abilities. At both grades, frequency‐tagged letter strings were discriminated from pseudofont strings (i.e. letter‐selectivity) over the left occipito‐temporal cortex, with effects observed at the individual level in 62% of children. However, visual words were not discriminated from pseudowords (lexical access) at either grade. Following 1 year of schooling, letter‐selective responses showed a specific increase in amplitude, a more complex pattern of harmonics, and were located more anteriorly over the left occipito‐temporal cortex. Remarkably, at both grades, neural responses were highly significant at the individual level and correlated with individual reading scores. The amplitude increase in letter‐selective responses between grades was not found for discrimination responses of familiar keyboard symbols from pseudosymbols, and was not related to a general increase in visual stimulation responses. These findings demonstrate a rapid onset of left hemispheric letter selectivity, with 1 year of reading instruction resulting in increased emerging reading abilities and a clear quantitative and qualitative evolution within left hemispheric neural circuits for reading.
Highlights
Reading is a complex brain function, which lies at the interface of several cognitive domains including vision and language
By capturing automatic processes without necessarily requiring explicit reading, classical electroencephalographic (EEG) studies have distinguished between ‘coarse-grained tuning’, in which a different response is observed for real letter strings than for non-letter objects or letter-like stimuli, and “fine-grained tuning”, in which a different response is observed for words than for non-legal letter strings, arising from sensitivity to well-formed patterns of assembled letters (Centanni, King, Eddy, Whitfield-Gabrieli, & Gabrieli, 2017; Centanni et al, 2018; Coch & Meade, 2016; Eberhard-Moscicka, Jost, Raith, & Maurer, 2015)
The current longitudinal study assessed the evolution of neural tuning to letter strings and its relationship with emerging reading abilities
Summary
Reading is a complex brain function, which lies at the interface of several cognitive domains including vision and language. We tested a large group of children (N = 39) at the beginning of formal reading instruction and 1 year later, both behaviorally and with frequency-tagging, known as fast periodic vsual stimulation, combined with EEG (FPVS-EEG) This approach is suitable to measure automatic discrimination of a categorical change: for instance, when streams of non-words are presented at 6 Hz and words are inserted periodically every five items, at 1.2 Hz. If words are discriminated from non-words, it gives rise in the EEG frequency domain to a peak of response amplitude at 1.2 Hz and its harmonics (i.e. exact integers of 1.2: 2.4, 3.6 Hz, etc.) (for a review: Norcia, Appelbaum, Ales, Cottereau, & Rossion, 2015). Based on the same approach in the domain of face perception development (Lochy, de Heering, & Rossion, 2019), we expected that the response would be concentrated on the first harmonic in grade 1, and more distributed to higher harmonics in grade 2
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
