PERCEPTUAL PRIMING EFFECT IN MENTALLY RETARDED PERSONS: IMPLICIT AND EXPLICIT REMEMBERING

Abstract

This study compared implicit and explicit memory in mentally retarded adults versus university students. Subjects were shown 20 increasingly complete pictures until they were correctly identified. After two retention intervals, 5 minutes and 1 week, half of 20 pictures and 10 new pictures were presented for identification using the same procedure. After identifying each picture, subjects were asked whether or not they had seen it before. Perceptual priming effects on picture fragment completing (implicit memory) and recognition rates (explicit memory) were compared. Recognition rates differed between the two groups irrespective of retention intervals. Both groups showed significant priming effects. In spite of their poor performance at recognition, the priming effect in the retarded group did not differ from that of the university students. A group×interval interaction was found. These results suggest that mentally retarded adults can remember past events as well as college students so far as information was processed implicitly. The above results, therefore, can demonstrate that performance on implicit memory does not improve with intelligence.