Asymmetries in intermanual transfer of training and motor overflow in adults with Down's syndrome and nonhandicapped children.

A sequential finger-lifting task was used to examine asymmetries in intermanual transfer of training and motor overflow in Down's syndrome adults and young, nonhandicapped children. Both groups exhibited more interlimb transfer of training from the left hand to the right hand than the reverse. This finding provides evidence for left-hemisphere specialization for the organization and control of sequential movement. While the motor overflow results were less compelling, they provide some evidence for left-hemisphere dominance for movement control in Down's syndrome persons. It is suggested that perhaps the same neural mechanisms are responsible for motor overflow and transfer of training asymmetries.