Effect of verbal and nonverbal short-term memory coding with normal and retarded children.

20 retarded children (CA 11.7 yr.), matched with 20 normal ones, were assigned to verbal or nonverbal stimulus conditions. Pairs of 8-point random shapes were shown as styrofoam objects or drawings. d' measures for adjacent positions showed better recall for verbal coding and three-dimensional stimuli. Serial position effects were noted. Coding and dimensionality interacted.