Nonretarded and mentally retarded children's performance on a manual-control task with and without visual feedback.

Performance differences between 10 nonretarded and 10 retarded persons on a manual-control task were examined. More specifically, the focus was on possible relationships between the subjects' abilities to control their response forces and the focus of their attention. The subjects, who were closely matched for MA, were required to exert force on a transducer within a selected force bandwidth for 3 seconds to obtain a reinforcer. Results suggested that the ability to discriminate internal cues is related to IQ differences.