Gene–environment interaction on neural mechanisms of orthographic processing in Chinese children

Abstract

The ability to process and identify visual words requires efficient orthographic processing of print, consisting of letters in alphabetic languages or characters in Chinese. The N170 is a robust neural marker for orthographic processes. Both genetic and environmental factors, such as home literacy, have been shown to influence orthographic processing at the behavioral level, but their relative contributions and interactions are not well understood. The present study aimed to reveal possible gene-by-environment interactions on orthographic processing at the behavioral and neural level in a normal children sample. Sixty 12 year old Chinese children from a 10-year longitudinal sample underwent an implicit visual-word color decision task on real words and stroke combinations. The ERP analysis focused on the increase of the occipito-temporal N170 to words compared to stroke combinations. The genetic analysis focused on two SNPs (rs1419228, rs1091047) in the gene DCDC2 based on previous findings linking these 2 SNPs to orthographic coding. Home literacy was measured previously as the number of children's books at home, when the children were at the age of 3. Relative to stroke combinations, real words evoked greater N170 in bilateral posterior brain regions. A significant interaction between rs1091047 and home literacy was observed on the changes of N170 comparing real words to stroke combinations in the left hemisphere. Particularly, children carrying the major allele “G” showed a similar N170 effect irrespective of their environment, while children carrying the minor allele “C” showed a smaller N170 effect in low home-literacy environment than those in good environment.

Environmental Risk Factors in Han and Uyghur Children with Dyslexia: A Comparative Study

“…Details concerning other factors, such as birth history, nursery period, and history of infantile illness, were unknown for the participants in our study. Furthermore, the etiology of DD is complex, and related neurology, genetics, and psychology have been investigated in many studies [ 2 , 9 , 10 ]. The present study considered only environmental risk factors affecting Han and Uyghur children with DD .…”

“…These genes can change the structure of protein, which may lead to changes in its functional properties. However, studies in different languages have yielded conflicting results[ 6 – 10 ].…”

Neural Mechanisms of Dorsal and Ventral Visual Regions during Text Reading

“…The materials included 200 items: 40 real characters (e.g., ), 40 pseudo-characters with real radicals in illegal positions (e.g., ), 40 non-characters with ill-formed components (e.g., ), 40 scrambled strokes (e.g., ) filled in 1 character space, and additional 40 real characters as fillers. Each stimulus was presented in the center of the computer screen for 1 s and participants were required to decide whether each stimulus was a real character or not (also see Su et al, 2015 ). Inverse efficiency score was calculated by dividing the response times by accuracy for the correct trials, which could provide a basis for processing efficiency independent of possible speed-accuracy trade-offs ( Townsend and Ashby, 1978 ), and the score was transformed to an inverse number of the z-score.…”

Altered connectivity of the dorsal and ventral visual regions in dyslexic children: a resting-state fMRI study

“…The children were required to decide whether each stimulus that was presented in the center of the computer screen for 1 s was a real character or not. The reaction time was divided by accuracy to yield a score, and the score was transformed to an inverse number of the z -score (Su et al, 2015 ). One child did not take part in the lexical decision experiment (She set her departure ahead in behavioral test because there is something urgent waiting for her) and thus sustained 46 data points for this task.…”