Effects of practice on recognition memory of mildly mentally retarded adults.

The effect of practice on recognition memory of mildly mentally retarded adults was investigated in two experiments using the Sternberg (1969) memory scanning paradigm. In Experiment 1, the slope and zero intercept for item-recognition functions under both fixed- and varied-set procedures decreased over seven sessions of practice among retarded adults and nonretarded children, remaining relatively constant among nonretarded adults. Because performance of only retarded subjects had not yet reached asymptote, Experiment 2 provided these subjects with additional practice at the same task (varied-set procedure only). After extended practice, slopes in the retarded group were near those for both nonretarded groups; therefore, although the generally poorer performance of retarded adults in this task may reflect some structural impairment, the initial level of deficiency is reduced by practice.