Priming In Chinese Character And Picture Recognition For Chinese Dyslexic Children

Dyslexia (reading disability) is a specific learning disability that is neurobiological in origin. It is characterized by difficulties with accurate and/or fluent word recognition and by poor spelling and decoding abilities. These difficulties typically result from a deficit in the phonological component of language that is often unexpected in relation to other cognitive abilities and the provision of effective classroom instruction. Secondary consequences may include problems in reading comprehension and reduced reading experience that can impede growth of vocabulary and background knowledge. Dyslexia is perhaps the most common type of learning disability affecting children, with prevalence rates ranging from 5 to 17.5 percent in children. At least 80% of children with learning disability have reading disability.A deficit in phonology represents the most robust and specific correlate of reading disability, but Chinese dyslexic children may have deficits in both phonology and orthography awareness. Lexical priming is a paradigm whitch could focus on the comprehension processes of word, but there are few researches on lexical priming for Chinese character. The present research expended the investigation to prming in phonological and orthographic processes. If Chinese dyslexic children have deficits in phonological and orthographic priming, we can understand the mechanism of deficit in comprehension process.The second question of the present research is whether the deficits observed in dyslexia are confined to the phonological representations. Given the massively interactive nature of word recognition, it is possible that priming deficits in dyslexia may extend beyond the phonological representation in the network. Specifically, a deficit in one part of the network, like phonolocial, might strain other parts, like semantic, resulting in observed deficits in semantic priming as well. The features of deficits in representation network are not clear in Chinese dyslexia, so we examined this by looking at semantic and orthographic priming as well as phonological priming.The third question of the present research is whether there is a deficit in priming for picture recognition, because Chinese characters are derived from pictographic character, which have characteristics as abstract picture. Whether the features of picture priming are the same as orthographic priming in Chinese character recognition is the main question that focused in the present study. We are also interested in the relationship between the picture priming and the dyslexia. All these questions are essential to the etiology of Chinese dyslexia and can provide evidence of diagnosis and remediation for Chinese dyslexia.Part 1: The Features of Epidemiology for Chinese dyslexic childrenObjective: To explore the distribution features of Chinese dyslexic children and examine the relationship between environmental factors and Chinese dyslexia, such as parenting styles and family social-economic status.Method: Two primary schools was chosen as the study site and all subjects were selected from students in grade five, A Logistic regression model was used to investigate the relationship between environmental factors and Chinese dyslexia. Results: Twenty five students were found out of dyslexia which consisted of 9.8% of all the students. Among the dyslexic children, 19 were boys and 6 were girls. The distribution difference between boys and girls was significant. The factors which entered the Logistic model were mother's literacy and marriage status of parents.Conclusion: Boys are inclined to have dyslexia than girls. The main risk factors for dyslexia in parenting style and family social-economic factors are mother's lower literacy and bad marriage status.Part 2: Graphic, Phonological and Semantic Priming in Chinese Character Recognition For Dyslexic Children Objective: To explore the difference of graphic, phonological and semantic priming in Chinese character recognition between dyslexic children and normal children. Method: A priming paradigm was used to let subjects complete lexical decision task. The differences of reaction time, priming effect and error rate between dyslexic children and normal children were analyzed.Results: The baseline adjusted facilitation of graphic, phonological and semantic priming in character recognition for dyslexic children were -0.010, -0.010, and 0.001 respectively. The dyslexic children even showed inhibition in graphic and phonological prime conditions. The facilitations under the three prime conditions were 0.026,0.026 and 0.022 for age controlled group. As for reading level controlled group, results were 0.062,0.058 and 0.031 respectively. The differences of priming effects between dyslexic children and normal children were significant, especially in graphic and phonological priming conditions. The possible order of the three priming effects (from high to low) was: graphic, phonological and semantic. The interaction between reading ability and priming was not significant. Conclusion: Results from the present study suggests that there is a general deficit in graphic and phonological processing in character recognition for Chinese dyslexic children. This phenomenon can be interpreted by connectionist models.Part 3: Prming Effect in Picture Categorizing Process for Chinese Dyslexic ChildrenObjective: To assess the difference of priming effect in visual picture categorizing task between dyslexic children and normal children.Method: Twenty-five dyslexic children and 50 control subjects (25 matched with chronological age and 25 matched with reading level) completed a masked picture priming experiment using pictorial stimuli. On each trial, a masked prime picture was briefly displayed. The participants'instructed task was to classify target stimuli as representing living or non-living objects. Priming effect and response error rate between dyslexic children and normal children was analyzed.Results: The adjusted facilitation of congruent pairs for dyslexic children was 0.061, and the two controlled group were 0.057 and 0.064 respectively. The difference between dyslexic children and controlled groups was not significant.Conclusion: Dyslexic children did not exhibit significant deficit in general objects picture's features processing.