Levels of processing and memory in mentally retarded and nonretarded persons

Individual differences in memory were examined from the levels of processing perspective. Mentally retarded persons were expected to be more superficial processors. The recall of nonretarded and two IQ levels of retarded young adults was compared following the presentation of pictorial stimuli with either a shallow processing, deep processing, or control orienting task. Shallow processing was induced by directing subjects to name the colors of the pictures. In the deep processing condition, subjects were told to say what the pictured object was used for. In the control condition, they were directed to look at the pictures. The stimuli were presented as an incidental learning task. Encoding condition was a between-subjects variable. Nonretarded subjects remembered more overall than did the two retarded groups, which did not differ. At each intelligence level, more stimuli were remembered in the deep processing condition than in the shallow condition. There was no interaction of intelligence level with encoding condition. The hypothesis that retarded persons process at a more superficial level was not supported. A “spread of encoding” deficit in retarded persons is favored to explain the recall differences obtained in this experiment.