Mentally Handicapped

Eighteen retarded Ss (mean IQ 50 and mean age 14 years) and 18 normal Ss (mean IQ 100 and mean age 7 years) participated in a study to isolate variables that differentially control discrimination learning and retention processes, and to evaluate contrasting theories on discrimination learning and menory processes of retarded and normal qhildren. The experimental design contained the following six independent variables: IQ groups (retardates vs. normal Ss), retention intervals (seconds vs. hours). kinds of test problems (ney vs. old), sources of interference (proactive vs. retroactive), types of interfering discrimination (new vs. old), and Ss. The dependent variable in all conditions was the vs response (on a discrimination test trial) expressed in terns of either percentage of correct responses or retention loss score in each level of the factorial experiment. Acquisition data shoved tha