Differences between mentally retarded and nonretarded persons' efficiency of auditory sentence processing.

Mentally retarded adolescents and MA-matched nonretarded children participated in three experiments designed to examine differences in language-processing efficiency. A compressed speech technique was used in Experiments 1 and 2. Experiment 3 relied on a sentence-picture verification procedure. Our results suggest that retarded and nonretarded individuals differ in the speed with which they are able to execute the semantic-analytic processes but not necessarily the phonological encoding processes that are involved in auditory language comprehension. In addition, the data suggest a possible group difference in the quality of the semantic representation encoded during sentence processing.

Semantic processing can facilitate free recall in mildly retarded adolescents.

The efficacy of semantic processing in free recall was investigated in two experiments with EMR adolescents. In Experiment 1, they were taught to use one of two semantic strategies for memorizing a 15-word list. Compared with controls, neither strategy helped recall either in original learning or transfer. In Experiment 2, one of the semantic strategies, a story mnemonic, was investigated further. Rather than being taught to construct their own stories as in Experiment 1, subjects in Experiment 2 were provided with experimenter-composed stories. They showed better immediate recall and retention after 2 months than did no-strategy controls. However, about 1 year after original learning, the retention of experimental and control subjects no longer differed. Discussion focused on the story mnemonic's potential utility and the criteria for judging such potential, e.g., amount of facilitation, ease of training and performance of the strategy, and the degree of its generalizability.