Study Design This study analyzed the asymmetry of a nonspinal sensory system, comparing healthy children and those with adolescent idiopathic scoliosis. Objectives To test the hypothesis that differences in neurologic functioning that have been observed in idiopathic scoliosis are confined to motor organization and that the etiology thus is a defect solely of the motor cortex. Summary of Background Data Recent reports associating scoliosis convexity with equilibrium control, central processing, handedness, and motor lateralization have suggested that idiopathic scoliosis is connected causally with the motor cortex. Methods Dichotic listening tests were performed on 20 healthy children and 31 children with adolescent idiopathic scoliosis. This tests perceptual asymmetry, and thus the organization of cognitive processing in the brain, a higher function that is not associated with posture or motor function. Results Subjects with scoliosis were significantly more lateralized for linguistic processing than the control group, indicating they had a greater degree of left-right asymmetry throughout their cortical organization. Conclusion In adolescent idiopathic scoliosis, the organization of the entire brain was more strongly lateralized than in subjects without scoliosis. It is unlikely that this caused or was caused by the spinal curvature. Subjects with adolescent idiopathic scoliosis showed generalized asymmetry of many functions and structures. An examination at the level of morphology and development is proposed.