Visual perceptual processing errors in children with nonverbal learning disabilities (NVLD)
Children with NVLD possess intact or enhanced verbal abilities in the presence of significant deficits in visual perceptual processing. These children also have social skills deficits that many researchers believe are a function of the child’s misinterpretations of information presented through a visual channel. The purpose of this study was to explore the processes by which children with NVLD interpret visual stimuli by using specific measures of the Rorschach Inkblot Test. It was hypothesized that, when faced with visual stimuli, children with NVLD would show four specific cognitive perceptual processing errors: visual distortion (X-%), failure of integration (DQ+), limited social attribution (M) and social distortion (M-). Children with NVLD often have coexisting Attention Deficit/Hyperactivity Disorder, Predominately Inattentive Type (ADHD/PI). However, researchers investigating NVLD have failed to consider the role of inattention in the NVLD presentation. Therefore, the second purpose of this study was to compare Rorschach responses of children with NVLD +ADHD/PI to children with ADHD/PI and a control group. Fifty-four students comprising three groups (n = 18 per group) participated in the study. Participants were identified as being right handed, primarily English speaking and free of gross neurological, sensory, language and psychotic disorders as well as co-existing diagnoses of Conduct Disorder, Major Depressive Disorder, and severe anxiety disorders. Participants completed the Vocabulary and Block Design subtests of the Wechsler Intelligence Scale-Third Edition (WISC-III), the Developmental Test of Visual-Motor Integration, the Rey-Osterreith Complex Figure Drawing and the Structural Interview for Diagnostic Assessment for Children for DSM-IV. The Kruskal Wallis technique was used to test for an overall difference between groups. Post hoc pairwise comparisons were conducted using Mann Whitney U. The results showed significant differences between the NVLD+ADHD/PI group relative to the ADHD/PI group and the control for X-% (p < .001), DQ+ (p < .01), and M (p < .05), but not for M- ( p = .96). These findings provide empirical validation that children with NVLD demonstrate three distinct perceptual processing errors that 1) cannot be attributed to inattention and 2) likely contribute to misinterpretations of the child’s physical and social world.