Evaluation of auditory sensory memory of mentally retarded and nonretarded persons
Campbell, E.M.; Meyer, P.A.
American Journal of Mental Deficiency 86(1): 50-59
1981
ISSN/ISBN: 0002-9351 PMID: 7270588 Document Number: 181695
Performance of mentally retarded and nonretarded persons was compared in 2 experiments designed to identify processes of auditory sensory memory. In 1 study backward masking of pure tones occurred for a group of retarded adolescents; no difference in masking functions were obtained for the retarded group and control groups of equal CA (chronological age) and MA (mental age). In the 2nd study a gap-detection task was used as an apparent index of echoic trace durability. Since retarded persons were hypothesized to have a less durable echoic trace, the unique prediction was made that they would outperform control subjects on the task. The retarded group was significantly more accurate and exhibited a lower threshold than did the nonretarded, CA-matched control group. The applicability of these tasks for investigations of mental development was noted, and suggestions were made concerning improvements and extensions of the present research. A theoretical model was proposed to incorporate the current pattern of results.