Lateralized sensorimotor asymmetries in normal, learning-disabled and brain-damaged young adults

Left-right asymmetries in sensorimotor abilities (based on the Tactile Finger Localization, Fingertip Number Writing, Finger Tapping, Grip Strength, and Tactual Performance Tests of the Halstead-Reitan Battery) were compared among groups of 30 normal, 60 learning-disabled, and 20 brain-damaged adults aged 17 to 29 yr. The normal and learning-disabled groups (which did not differ) had significantly fewer asymmetries than the brain-damaged group. However, 36% of the learning-disabled group who had a Halstead Impairment Index greater than or equal to 0.4, also had significantly more sensorimotor asymmetries than the normals. These results support the idea of an association between neurobehavioral deficits and learning disabilities for this age group.