Recognition memory as a function of encoding strategy and stimulus codability.

The primary purpose of this research was to determine how imaginal and verbal encoding strategies intereact with various stimulus characteristics to either enhance or retard recognition; the secondary purpose of these studies was to test the conceptual coding hypothesis of Ellis, 1972. A between-groups multivariate factorial analysis of covariance experiment and a within-subjects multivariate factorial analysis of variance experiment were conducted. In Experiment 1 it was found that low-codability shapes were better recognized under the verbal encoding set rather than the imaginal encoding verbal encoding sets; and high-codability shapes were not better recognized than low-codability shapes. However, in Experiment 2, where instructional set was a within-subjects factor, it was found that low-codability shapes were not better recognized under the verbal encoding set than the imaginal encoding set.

The effect of overt rehearsal on motor short-term memory.

The effects of different types of rehearsal on the recall of a blind motor movement were explored. Immediate recall and delayed recall (covert rehearsal) were compared to recall after the overt rehearsal of either movement distance or end-location. Spontaneous decay was evident in a large increase in variable error (VE) for all rehearsal conditions even though the location cue was reliable. Massed distance rehearsals yielded less VE than spaced, and VE increased with successive rehearsals, providing further support for spontaneous decay. Constant error showed a central tendency effect and decreased in overshooting over time. Longer movements yielded more VE than shorter, and the increase in VE over time was greater for longer movements, suggesting that retention characteristics may differ as a function of movement length.