Manual asymmetries of motor sequencing in boys with reading disability

Boys with reading disability were asked to tap two mechanical keys in time to the beat of a metronome, with left and right hand alone, and with alternating hands. On the single hand trials these boys tapped as well as normal boys with both left and right hands, but when asked to alternate hands, their tapping stability, particularly of the left hand, deteriorated significantly and was worse than that of much younger normal boys. It is argued from evidence from patients with surgical commissurotomies that the motor deficiency in synchronizing left and right hands may be due to a disturbance in interhemishperic cooperation in the boys with reading disability, and it is suggested that the reading problems of these children may be the consequence of a developmental delay in interhemispheric cooperation.