Michael J. Watkins

The role of rehearsal in short-term memory

Several widely accepted models of memory postulate that the adequacy of an items registration in long-term storage is a positive function of its length of stay in the short-term store. However, when short-term storage times were measured, these times did not predict long-term recall or recognition. Two further experiments showed that neither the length of an items stay in short-term storage nor the number of overt rehearsals it received was related to subsequent recall. It is concluded that the “maintenance” and “elaborative” aspects of rehearsal can be clearly separated, and that the duration of rehearsal is related to long-term memory and learning only in the latter case. Maintenance rehearsal does not lead to an improvement in memory performance.

The modality effect in free and serial recall as a function of phonological similarity

Subjects read lists of phonologically similar words (such as bud, cub, tuck, bug, duck, …) or lists of phonologically dissimilar words (such as bead, cab, tick, bog, deck, …) under instructions either for free or for serial recall; additionally, reading was either silent or overt. In free recall primary memory capacity was not affected by phonological similarity, whereas an advantage for the overt over the silent presentation mode was observed with the dissimilar but not the similar lists. Further, phonological similarity reduced the size of the modality effect in serial recall. Apart from its interactive effects with mode of presentation, the effect of similarity on free recall was beneficial for all except the recency items, whereas similarity reduced performance in serial recall. These results in particular allow dismissal of some hypotheses for the modality effect, and in general pose a problem for theories of how similarity affects memory.

Continuity between Recall and Recognition.

The discontinuity hypothesis is that recall and recognition are in some sense fundamentally different memory processes. The continuity hypothesis is that retrieval in both modes is essentially the same, a joint product of the information stored in the past and that in the immediate environment. Data from a simple experiment and a brief discussion of other studies in the literature support the proposal that the continuity view is both more parsimonious and more fruitful than the discontinuity view.

On negative transfer: Effects of testing one list on the recall of another

Two experiments were designed to clarify the priority effect in the A-B, A-C paradigm, higher first-list than second-list recall in the MMFR test following equal amounts of study of both lists. The results of the experiments suggested that the priority effect is a consequence of severe impairment of learning A-C pairs when A-B pairs are not tested prior to the presentation of A-C pairs. This impairment of learning of A-C pairs, negative transfer, is independent of specific A-B pairs tested, but its overall magnitude appears to be an inverse function of the proportion of pairs in the A-B set that are tested. Since no theory of transfer or interference makes any provisions for the effects of testing of one list on the learning and recall of another, the testing effects observed in these experiments are puzzling.

Context effects in recognition memory for faces

Abstract Three experiments showed that a study-to-test change in the presentation context of pictures of unfamiliar faces impairs their recognition. Experiment I showed that a face studied beside a second face was more likely to be recognized when accompanied by the same rather than a different face. In Experiment II, faces were paired with descriptive phrases and again re-presentation of the study context was shown to enhance recognition. Experiment III replicated the finding of Experiment II with a forced-choice rather than a free-choice procedure. It is argued that these findings are consistent with episodic theory but pose a problem for a tagging theory of retention.

A tactile suffix effect

Evidence for a representational tactile memory was obtained from a tactile analogue of the auditory suffix effect. In two experiments, a short sequence of tactile stimuli applied to the fingers was followed by an acoustic (control) or tactile (suffix) recall signal. The serial position curves for the two conditions were compared. They revealed similar and strong primacy effects, but recall of the last few stimuli was higher in the control condition. This terminal control advantage was attributed to the retention of raw tactile information.

Recency effect in recall of a word list when an immediate memory task is performed after each word presentation

Subjects studied 12-word lists for free recall. During presentation of the lists, each word was followed by a supraspan sequence of digits, which the subjects tried to reproduce. This task, unlike those used in previous research with this continual distractor procedure, presumably taxed immediate memory capacity to the full. Nevertheless, the word recall data showed a pronounced recency effect. Moreover, the magnitude of the recency effect was found to be just as great with this task as with a more typical task in which the demands on immediate memory are likely to be fewer. These findings reinforce the emerging view that the recency effect need not be the product of immediate memory.