INPUT CAPABILITY AND SPEED OF PROCESSING IN MENTAL-RETARDATION

The minimum stimulus duration for criterion accuracy and the minimum interval between presentation of a test and presentation of a masking stimulus for criterion accuracy were determined for mildly (mean IQ 55.25) and moderately (mean IQ 47.25) retarded adults and normal controls of the same MA and CA. Five groups of 8 Ss were tested: All adult Ss were in their 20s, and 2 groups of children whose mean CAs were 9.1 and 7.7 yrs served as MA controls for the milds and moderates, respectively. The procedure was replicated 3 times in 3 separate sessions. Both retarded groups required longer stimulus durations as well as longer masking intervals for criterion accuracy than did both the MA and the CA control groups. Results are consistent with deficiencies in both iconic storage and speed of information processing in mental retardation. These deficiencies, furthermore, cannot be accounted for on the basis of low MA. (17 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1979 American Psychological Association.