The utility of math difficulties, internalized psychopathology, and visual-spatial deficits to identify children with the nonverbal learning disability syndrome: evidence for a visualspatial disability.
This study examined the criteria currently employed to identify children with the nonverbal learning disability syndrome (NVLD). The most widely accepted definition of NVLD relies on deficits in visual-spatial-organizational, tactile-perceptual, psychomotor, and nonverbal problem-solving skills. These deficits are believed to coexist with strengths in rote verbal learning, phoneme-grapheme matching, verbal output, and verbal classification. The combination of these assets and deficits has been hypothesized to lead to psychosocial and academic problems, including difficulties with mathematics and increased rates of psychopathology. This study compared performance of three groups of children: those with NVLD, those with verbal learning disabilities (VLD), and controls. The results show that the criteria currently employed to identify children with NVLD may not adequately differentiate them. In contrast to previous findings, the study reveals that children with NVLD can demonstrate good math abilities when performing certain types of math tasks, especially those that draw on their robust verbal skills. Also in contrast to most previous findings, in this study children with NVLD (and normal controls) demonstrated lower rates of psychopathology than children with VLD. Finally, for children with NVLD it appears that their visual-perceptual deficits may include a primary deficit in locating objects in space. Based in part on the findings of this study, it may be helpful for diagnostic and treatment purposes to reserve the term Nonverbal Learning Disability for children whose visual-spatial deficits are primary and severe enough to affect academic performance in subjects such as written mathematics. Given the integral nature of social relations in children's lives, a separate category (e.g., social processing disorder) could be created for children whose social skills deficits are primary and impair their social interactions. A broader nonverbal learning model or syndrome, as conceptualized by Rourke (1995), could be retained for describing a broader constellation of assets and deficits across disease types.