Picture perception in Chinese dyslexic children： an eye-movement study

Background Currently, whether or not there is visuospatial impairments in Chinese dyslexic children is still a matter of discussion. The relatively recent application of an eye-tracking paradigm may offer an opportunity to address this issue. In China, in comparison with reading studies, there have not been nearly as many eye movement studies dealing with nonreading tasks such as picture identification and whether Chinese children with dyslexia have a picture processing deficit is not clear. The purposes of the present study were to determine whether or not there is visuospatial impairments in Chinese dyslexic children. Moreover, we attempted to discuss whether or not the abnormal eye movement pattern that dyslexic subjects show during reading of text appropriate for their age is a consequence of their linguistic difficulties. Methods An eye-link II High-Speed Eye Tracker was used to track the series of eye-movement of 19 Chinese dyslexic children and 19 Chinese normal children. All of the subjects were presented with three pictures for this eye-tracking task and 6 relative eye-movement parameters, first fixation duration, average fixation duration, average saccade amplitude, mean saccade distance, fixation frequency and saccade frequency were recorded for analysis. Results Analyzing the relative parameter among three pictures, except for the fixation frequency and the saccade frequency, other eye-movement parameters were significantly different among the three pictures （P 〈0.05）. Among the three pictures, the first fixation duration was longer, and the average fixation duration, the average saccade amplitude and the mean saccade distance were shorter from picture 2 to picture 3. Comparing all eye-movement parameter between the two groups, the scores of average saccade amplitude （P=-0.017） and the mean saccade distance （P=0.02） were less in the dyslexia group than in the normal group （P 〈0.05）, other parameters were the same in the two different groups （P 〉0.05）. Conclusions The characteristics of the pictures can significantly influence the visuospatial cognitive processing capability of the Chinese children. There is a detectable disability for the Chinese dyslexic children in the visuospatial cognitive processing： their saccade amplitude and mean saccade distance are shorter, which may be interpreted as specific for their reading disability.

Evaluating autism in a Chinese population:the Clinical Autism Diagnostic Scale

Background:The purpose of this study was to report on the psychometric measures and discriminatory function of a new diagnostic test for autism spectrum disorders,the Clinical Autism Diagnostic Scale(CADS).Methods:The CADS was used to test 216 children in the study,including 86 with low-functioning autism specturm disorders(ASD),16 children with highfunctioning ASD,16 with pervasive developmental disorder,not otherwise specified,7 with Asperger syndrome,65 with typical development,11 children with language impairments and 15 with intellectual disabilities.Ages ranged from 38-73 months.Behaviors for the groups were compared across seven domains.Results:The results indicated the instrument was reliable,valid,and successfully differentiated the different groups of children with and without autism.All ASD groups were found to display difficulties in the domains of sensory behaviors and stereotyped behaviors.The play and social domains were found to measure similar underlying concepts of behaviors,while the receptive language and expressive language domains were also found to measure similar underlying-language concepts.The group of children diagnosed as having low-functioning autism performed less well on all tested domains in the instrument than did the other three groups of children with ASD,and these other three groups each also presented unique patterns of behaviors and differed on individual domains.Conclusions:CADS is a reliable and valid test.It successfully differentiates the abilities of children with ASD at different levels of functioning.