| Abstract: | Compared iconic memory processes of 17 undergraduates and 18 retarded Ss (primarily aged 18–28 yrs; IQ 56–77) in 4 experiments. In Exp I, a partial report paradigm was used in which 6 retarded and 6 undergraduate Ss were presented 6 pictures under 4 intervals (0–500 msec). In Exp II, using 5 Ss in each group the same procedure as in Exp I was used but letters as well as pictures were included. Results show that although overall performance for retarded Ss was poor, they did better with letters than with pictures—a reverse of the finding with undergraduate Ss. In Exp III, 2 retarded Ss were given extended practice and incentive to perform well. Asymptote was reached in 10 days but never equaled performance of unpracticed undergraduates. In Exp IV, using 5 Ss in each group, information load was varied from 1 to 4 items, and a masking stimulus was used to interrupt processing following 6 intervals that lasted up to 250 msec. Results show that (1) there are quantitative differences between intelligence groups in iconic capacity; (2) retarded Ss process information more slowly, a difference that increases with increasing information load; and (3) there are substantive structural differences in iconic memory of retarded and nonretarded Ss. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
