Humphries T, Krekewich K, Snider L
Hospital for Sick Children, Ontario Institute for Studies in Education, University of Toronto, Ontario, Canada.
Percept Mot Skills. 1996 Jun;82(3 Pt 1):979-87. doi: 10.2466/pms.1996.82.3.979.
The presumed sensorimotor basis of the nonverbal learning disability syndrome was investigated among 90 learning disabled boys (M age = 6 yr., 8 mo., SD = 12.2 mo.) with sensory integrative dysfunction. The majority of the boys were Caucasian, lower to middle socioeconomic status, and from urban, English-speaking families. 14% (n = 13) of the boys satisfied core discrepancy criteria for nonverbal learning disability, including both a significantly higher Wechsler Verbal than Performance IQ and a higher standard score in Reading than Arithmetic on the Wide Range Achievement Test. Compared with a control group of 19 boys from the same sample who had no significant discrepancies, boys with nonverbal learning disability had significantly greater weaknesses in space visualization and visuomotor coordination. As predicted, rote verbal memory and syntactical strengths were also exhibited by boys with nonverbal learning disability, but the two groups did not differ significantly.