Abstract
Acquisition and retention of pursuit rotor performance for 100 EMR and normal Ss under the conditions of equal practice and learning to an equated mean level of performance with and without immediate feedback was investigated. (a) Immediate feedback had no effect on performance, (b) EMRs with additional practice performed as well as the normals, and (c) retention by EMRs having learned to an equated mean level of performance was superior to that of normals. The effects of sex and race were reported. Possible explanations were discussed.