Beeinträchtigungen der visuellen Wahrnehmungsleistungen von Kindern und Jugendlichen mit Entwicklungsauffälligkeiten

Abstract

Visual perception is an important cognitive ability with major influence on child development. To support the results of studies published previously the visual perceptual abilities of children suffering from dyslexia, dyscalculia, and developmental coordination disorder as well as children that had a perinatal or early childhood stroke are compared. Different models of visual perceptual processing exist. The present work refers to Frostig´s three level model describing visual perception as an exceptional level between sensation and cognition. As the diagnosis Visual Perceptual Disorder is neither provided by the ICD-10 nor by the DSM-5 the guidelines of the Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften (AWMF) (German working committee of the scientific medical professional associations) are used within the framework of this dissertation. The scores of 241 children aged between 9 and 14 years on the German version of the Developmental Test of Visual Perception - Adolescent and Adult (DTVP-A) are compared. The nonparametric Kruskal-Wallis-H-Test was used for comparative analyses. Furthermore the percentage of children of the different groups who achieved clinical relevant scores and those children who have visual perceptual disorders based on the guidelines of the AWMF are presented. Children with dyslexia achieve superior results compared to children from the other groups. Based on pairwise comparisons results of the main scale General Visual Perception Index tend to differ between the dyscalculia and the dyslexia group. No significant differences between groups are found in the subscale Motor-Reduced Visual Perception Index. In the subscale Visual-Motor Integration Index stroke and dyslexia group differ significantly in pairwise comparisons. Further significant differences are observed in the pairwise group comparisons of the scores in the subtests Form Constancy (dyslexia vs. dyscalculia), Copying (dyscalculia vs. coordination disorder) and Visual-Motor Speed (dyslexia vs. dyscalculia and dyslexia vs. stroke). 39 % of the children suffering from dyscalculia, 36 % of the children who suffered a stroke, 33 % of the children with coordination disorder and 11 % of those with dyslexia achieve clinical relevant scores (= scores at least 1.5 SD below standardized average) on the General Visual Perception Index. Children within the stroke group remarkably often achieve clinical relevant scores in the Visual-Motor Integration Index (43 %) as well as in the subtests Visual Closure and Form Constancy (18 %, respectively). A large amount of children with dyslexia achieve clinical relevant results in the subtests Copying and Visual Closure (17 %, respectively). Within the dyscalculia group a large number of children perform 1.5 SD below average in the subtests Visual Closure (23 %), Form Constancy, Copying and Visual-Motor Search (26 %, respectively). Children with coordination disorder most frequently achieve clinical relevant results in the subtests Copying (38 %), Form Constancy (24 %), Visual Closure (19 %), Figure-Ground and Visual-Motor Search (14 %, respectively). Interestingly, as compared to the other groups children with dyslexia show less overall visual perceptual deficits. A Visual Perceptual Disorder according to the AWMF-criteria (total score 1.5 SD below average on the DTVP-A and 1.5 SD below the General IQ) can be diagnosed for 11 % of the children of the stroke group and for 3 % of the dyslexia as well as the dyscalculia group. When using the Verbal Comprehension Index as reference score instead of the General IQ this pattern changes: 21 % of the stroke, 3 % of the dyslexia and 13 % of the dyscalculia group preserve the diagnosis. Concluding, the results presented in this dissertation thesis show the high incidence of visual perceptual deficits in children with developmental problems. As deficits in visual perceptual abilities differ between groups it seems important to use standardized visual perceptual tests in develop-mental diagnostics and intervention design. Furthermore, the diagnosis Visual Perceptual Disorder has to be defined more precisely. Hence, further studies on the role of visual perceptual deficits in children with developmental disorders such as developmental coordination disorder, dyscalculia, dyslexia and childhood stroke seem necessary. The same holds for studies on the effectiveness of visual perceptual therapies.