N1 lateralization and dyslexia: An event‐related potential study in children with a familial risk of dyslexia

Abstract

The rapid automatic specialized processing of printed words is signalled by the left‐lateralization of the N1 component in the visual event‐related potential (ERP). In the present study, we have investigated whether differences in N1 lateralization can be observed between Dutch children with and without (a familial risk of) dyslexia around the age of 12 years using a linguistic judgement task. Forty‐five participants were included in the ERP analysis, 18 in the low familial risk group without dyslexia, 15 in the high familial risk group without dyslexia, and 12 in the high familial risk group with dyslexia. The results showed that although the N1 peaked slightly earlier in the left hemisphere, the N1 amplitude was right‐lateralized in all groups. Moreover, there were no group differences in N1 amplitude or latency, and there was no relationship between reading (related) test scores and N1 characteristics. The results of the present study and our previous findings in adults suggest that print‐tuning lateralization is a process that is still developing in adolescence. Because other studies did find N1 lateralization in younger readers with a print versus nonprint contrast, the current results seem to indicate that differences in N1 lateralization also depend on the experimental paradigm.

Typical and Atypical Development of Visual Expertise for Print as Indexed by the Visual Word N1 (N170w): A Systematic Review

“…No such studies were conducted in pre-literate TD and at-risk of DRD/PR children. In school-aged children, four studies showed similar mean latencies for both TD and DRD/PR groups (Kast et al, 2010 ; Maurer et al, 2011 ; Hasko et al, 2013 ; Zhao et al, 2014 ), whereas one study reported that controls had longer mean latencies than DRD (van Setten et al, 2019 ). In young adults, two studies reported longer mean latencies for DRD than controls (Savill and Thierry, 2011a ; Waldie et al, 2012 ).…”

“…Thirty-one studies explored the N170w in school-aged children, of which 14 compared TD with DRD/PR. Five studies showed a larger N170w amplitude for DRD/PR as compared to controls (Brem et al, 2013 ; Fraga González et al, 2014 , 2016b ; Zhao et al, 2014 ; van Setten et al, 2019 ), five showed a larger N170w amplitude for controls than DRD/PR (Maurer et al, 2007 , 2011 ; Jucla et al, 2010 ; Kast et al, 2010 ; Bakos et al, 2018 ), and four showed no difference (Araújo et al, 2012 ; Hasko et al, 2013 ; Kemény et al, 2018 ; Pleisch et al, 2019 ). One specific study further divided the TD and DRD children into young ( M age = 8.3) and old ( M age = 11.4) sub-groups and found that in younger groups, TD exhibited a more negative N170w than DRD/PR, whereas the opposite pattern was found for older children (Maurer et al, 2011 ).…”

“…van Setten et al (2016Setten et al ( , 2019 were interested in the assumed interaction of mean N170w latency and hemispheric distribution in TD and DRD groups and found a significantly longer mean N170w latency in the right hemisphere compared to the left in both TD and DD/PR groups in young adults and schoolaged children.…”

“…This change occurs shortly after the start of formal reading instruction, contributing to letter-speech sound integration in the form of grapheme-phoneme correspondences (Maurer et al, 2006 ; Brem et al, 2013 ). However, for individuals with DRD, the response lateralization showed no consistent pattern: left (e.g., Araújo et al, 2012 ), bilateral (e.g., Fraga González et al, 2014 ), or right-lateralized (e.g., van Setten et al, 2019 ) distributions were reported.…”

Lateralization of orthographic processing in fixed-gaze and natural reading conditions

“…The copyright holder for this preprint this version posted June 21, 2022. ; https://doi.org/10.1101/2022.06.20.496859 doi: bioRxiv preprint instead of leftward lateralization of the word-evoked N1 ERP component (Fraga González et al, 2014Setten et al, 2019). Studies based on fixed-gaze experimental paradigms also revealed enhanced brain activation in the left occipito-temporal region for processing of orthographic information in experienced readers compared to beginners, the dominance of the left hemisphere in orthographic processing was shown to become more prominent with the advancement of reading skills (Brem et al, 2010;Dehaene et al, 2010Dehaene et al, , 2015Pegado et al, 2014).…”