Two experiments examined the relationship between implicit and explicit measures of memory for information encoded in a motoric task, called data entry. In both experiments, subjects entered lists of digit sequences with a computer keypad. They were retested on the same task after a delay of up to 1 month. At retention, implicit memory for the digit lists was evidenced by faster entry of old relative to new lists in both experiments. In Experiment 1, subjects were able to discriminate old from new lists. Recognition memory of old lists was better after than before entering the lists. In Experiment 2, perceptual and motoric contributions to the old/new difference in typing speed were isolated by means of a transfer paradigm. The results showed that the entry-speed advantage for the old lists was due to the separate reinstatement at the retention test of both perceptual and motoric procedures encoded earlier. Implicit and explicit measures of memory were found to be dependent rather than independent. The findings from this study are interpreted within a framework of memory based on procedural reinstatement.

In two experiments, subjects recalled one of two letter sequences following a digit-filled retention interval. Recall performance was increased by precues informing subjects which letter sequence would be tested, and the cuing advantage remained throughout 60-digit retention intervals. No improvement was found, however, for cues occurring after the letters but before the digits. The cuing effects were attributed to encoding, not rehearsal, processes and were explained by a version of the Estes perturbation model, which included a long-term storage component and a fixed perturbation probability.

In two experiments, subjects recalled one of two letter segments following a digit-filled retention interval. In Experiment 1, recall expectancy was manipulated by using precues that correctly informed or misinformed subjects concerning which letter segment would be tested for recall. In Experiment 2, item importance was varied by precuing one segment as important but requiring that the uncued segment be recalled first. Recall performance was very low under conditions of low expectancy and low segment importance, but the slopes of the retention functions did not demonstrate more rapid forgetting than under standard conditions. The previous observations of very rapid forgetting from primary memory may be a function of an elevated initial recall level in the earlier studies. Our retention functions were compared with predictions of the Estes perturbation model. The findings suggested that when secondary memory processes were reduced, forgetting order information from primary memory occurred at the same rate as that estimated on the basis of previous studies using the standard distractor task. 671The distractor paradigm developed by Brown (1958) and Peterson and Peterson (1959) has been used to assess short-term memory (i.e., retention over brief time intervals). Findings from this paradigm have revealed a steep retention function, which has been interpreted as Experiment I was conducted at the University of Colorado, Boulder, where R.E.T. was on sabbatical leave 1984-1985.

No abstract

In two experiments, we examined the acquisition and retention of a letter-detection skill with a consistent-mapping procedure. In Experiment 1, subjects were trained from 0 to 4 sessions at detecting the letter H in displays containing random letters, and retesting occurred after a 1-month delay. Performance improved and in some cases became more automatic, and the performance level was maintained over the retention interval. When tested with a prose passage, the high error rate on the word THE was eliminated after training and after the retention interval, regardless of the amount of training. In Experiment 2, two subjects were given 12 sessions of training followed by a retention test 6 months later. For 1 subject there was also a retention test 15 months after acquisition. Performance improved dramatically with training, and substantial but not complete automaticity was achieved. Performance on the retention tests was close to the final acquisition level. The surprising lack of forgetting in this study was contrasted with the substantial forgetting typically found in studies of verbal learning.