Revisiting distinctive processes in memory

In three experiments, we examined the relationship between orthographic and phonological distinctiveness and incidental recall. In each experiment, participants were given a surprise free recall test after they read words aloud as quickly and accurately as possible. The pattern of results replicated those reported in Cortese, Watson, Wang, and Fugett (2004) for intentional and explicit free recall and recognition memory tasks in which items were read silently. Specifically, we found that phonological-to-orthographic neighborhood size influenced recall performance, whereas orthographic-to-phonological consistency and phonological-to-orthographic consistency did not. Also, we failed to replicate the orthographic-tophonological consistency effect reported by Hirshman and Jackson (1997), and argue that their results were due to a confounding of consistency with phonological neighborhood size. Our results suggest that the processing of words sharing both orthography and phonology with a large number of words produces interference that reduces one’s ability to remember them.     

Developmental changes in the lag effect: An encoding hypothesis for repeated word recall

A differential encoding hypothesis for the lag effect in free recall was tested developmentally. Fourth- and eighth-grade children and college adults were shown a list of words, with some repeated at various lag intervals. Lag functions in repeated word recall were found to vary with age. An encoding hypothesis, modified to provide specificity for the time at which differential encoding takes place, was used to account for the results. Finally, it was suggested that the lag paradigm could be utilized to assess developmental differences in processing strategies, as perhaps a more sensitive, and general, alternative to the overt rehearsal technique.     

Backward recall and the word length effect

The word length effect, the finding that words that have fewer syllables are recalled better than otherwise comparable words that have more syllables, is one of the benchmark effects that must be accounted for in any model of serial recall, and simulation models of immediate memory rely heavily on the finding. However, previous research has shown that the effect disappears when participants are asked to recall the items in strict backward order. The present 2 experiments replicate and extend that finding by manipulating the participant's foreknowledge of recall direction (Experiment 1) and by giving the participant repeated practice with one direction by blocking recall direction (Experiment 2). In both experiments, a word length effect obtained with forward but not backward recall. The results are problematic for all models that currently have an a priori explanation for word length effects. The finding can be accounted for but is not predicted by Scale-Independent Memory, Perception, and Learning (SIMPLE), a model in which item and order information are differentially attended to in the 2 recall directions.     

Contextual variability and serial position effects in free recall.

In immediate free recall, words recalled successively tend to come from nearby serial positions. M. J. Kahana (1996) documented this effect and showed that this tendency, which the authors refer to as the lag recency effect, is well described by a variant of the search of associative memory (SAM) model (J. G. W. Raaijmakers & R. M. Shiffrin, 1980, 1981). In 2 experiments, participants performed immediate, delayed, and continuous distractor free recall under conditions designed to minimize rehearsal. The lag recency effect, previously observed in immediate free recall, was also observed in delayed and continuous distractor free recall. Although two-store memory models, such as SAM, readily account for the end-of-list recency effect in immediate free recall, and its attenuation in delayed free recall, these models fail to account for the long-term recency effect. By means of analytic simulations, the authors show that both the end of list recency effect and the lag recency effect, across all distractor conditions, can be explained by a single-store model in which context, retrieved with each recalled item, serves as a cue for subsequent recalls.     

Sequential consistency and subjective clustering in the multitrial free recall of children

The organization imposed by children on lists presented in a multitrial free recall task was investigated in two experiments. In the first, 6 and 9 year olds were tested for multitrial free recall of an unstructured noun or mixed list, followed by two sorting trials. Organization was quantified using two structurally comparable indices. One was an index of subjective clustering, based on individual word groupings determined in the sorting trials, and the other was an index of the sequential consistency of recall order over successive trials. The older children had significantly higher scores on recall and subjective clustering but there was no age effect on sequential consistency. In the second experiment 6, 8 and 10 year olds were tested for multitrial free recall of line drawings of common objects. Two sorting trials followed and organization was quantified using the subjective clustering and sequential consistency indices. Recall and subjective clustering scores again showed significant increases with age. As before, no age effect on sequential consistency was found. The results were interpreted in terms of a differential sensitivity of the two indices to an age-related qualitative change in the basis of organization.     

Associative retrieval processes in free recall

I present a new method for analyzing associative processes in free recall. While previous research has emphasized the prominence of semantic organization, the present method illustrates the importance of association by contiguity. This is done by examining conditional response probabilities in the output sequence. For a given item recalled, I examine the probability and latency that it follows an item from a nearby or distant input position. These conditional probabilities and latencies, plotted as a function of the lag between studied items, reveal several regularities about output order in free recall. First, subjects tend to recall items more often and more rapidly from adjacent input positions than from remote input positions. Second, subjects are about twice as likely to recall adjacent pairs in the forward than in the backward direction and are significantly faster in doing so. These effects are observed at all positions in the output sequence. The asymmetry effect is theoretically significant because, in cued recall, nearly symmetric retrieval is found at all serial positions (Kahana, 1995; Murdock, 1962). An attempt is made to fit the search of associative memory model (Raaijmakers & Shiffrin, 1980, 1981) with and without symmetric interitem associations to these data. Other models of free recall are also discussed.     

Identity and similarity in repetition blindness: no cross-over interaction

The difficulty in reporting both occurrences of a repeated item is a phenomenon referred to as repetition blindness (RB). RB has been proposed to result from temporal limitations in creating separate episodic tokens for a twice-activated type. Recently, Chialant and Caramazza (Cognition 63 (1997) 79-119) disputed the conventional view that RB for non-identical words (orthographic RB, as in lice and lick) results from the same mechanism as identity RB, and proposed that orthographic RB arises from competition for lexical selection. Supporting evidence was that identical and merely similar words showed different amounts of RB as a function of stimulus onset asynchrony (lag). Four experiments failed to replicate Chialant and Caramazza's finding that identity RB decreases, but orthographic RB increases, as a function of lag. Instead, RB for all stimuli, including homonym pairs, declined monotonically with lag. These results are consistent with a common mechanism underlying RB for identical and orthographically similar words and with prior research suggesting that RB in similar words occurs at a sublexical level.     

Recognition failures and free-recall failures: Implications for the relation between recall and recognition

Experiments showing that in cued recall subjects can recall words that they had previously failed to recognize have been taken to refute generate-recognize theories of recall, for those theories predict that recall is dependent on recognition. None of these experiments, however, has provided an appropriate test of Bahrick’s (1970, 1979) generate-recognize theory, which explicitly refers to words that are accessible to cued recall but not to free recall, that is, tofree-recall failures. When the experimental procedure was modified so as to provide tests of this theory, no evidence was found of any greater dependency between recall and recognition of free-recall failures than between recall and recognition overall. Free-recall failures do not, therefore, constitute any exception to many previous experimental findings that conform with the Tulving-Wiseman law, and so the account offered by Bahrick’s generate-recognize theory may be rejected. The results also suggest an explanation for some other conflicting evidence on whether recall and recognition are dependent or independent.     

The effects of free recall testing on subsequent source memory

The testing effect is the finding that prior retrieval of information from memory will result in better subsequent memory for that material. One explanation for these effects is that initial free recall testing increases the recollective details for tested information, which then becomes more available during a subsequent test phase. In three experiments we explored this hypothesis using a source-monitoring test phase after the initial free recall tests. We discovered that memory is differentially enhanced for certain recollective details depending on the nature of the free recall task. Thus further research needs to be conducted to specify how different kinds of memorial details are enhanced by free recall testing.     

The spacing effect in the free recall of homogeneous lists: present and accounted for

Memory performance nearly always improves as a function of the spacing between repetitions. However, previous studies indicated that college students exhibited no spacing effect in the free recall of lists composed exclusively of words sampled from a single semantic category. We explored this puzzling phenomenon in two experiments. We found that the spacing effect in free recall can occur with homogeneous lists. Most interestingly, the effect seems to depend on the number of items (lag) separating spaced repetitions. Short lags between spaced repetitions yield a spacing effect, whereas longer lags do not.     

Spacing and lag effects in free recall of pure lists

Repeating list items leads to better recall when the repetitions are separated by several unique items than when they are presented successively; thespacing effect refers to improved recall for spaced versus successive repetition (lag > 0 vs. lag = 0); thelag effect refers to improved recall for long lags versus short lags. Previous demonstrations of the lag effect have utilized lists containing a mixture of items with varying degrees of spacing. Because differential rehearsal of items in mixed lists may exaggerate any effects of spacing, it is important to demonstrate these effects in pure lists. As in Toppino and Schneider (1999), we found an overall advantage for recall of spaced lists. We further report the first demonstration of a lag effect in pure lists, with significantly better recall for lists with widely spaced repetitions than for those with moderately spaced repetitions.     

The spacing effect: Additions to the theoretical and empirical puzzles

Four studies examined the MP-DP effect (spacing effect) in four quite different situations: recognition of letters, verbal discrimination, short free recall lists, and recall of MP items presented twice, with an intervening interval inserted to produce forgetting. MP-DP differences were found in all studies. Of particular interest were three interactions. Subjects with a low criterion of responding in the letter study lost the MP-DP effect over a 30-sec delay, and subjects with a high criterion did not. A clear MP-DP effect, but no lag effect, was found only with unmixed verbal discrimination lists. In free recall, a sharp lag effect was shown for words presented three times but not for words presented twice. A forgetting interval inserted between the two occurrences of an MP item did not appreciably aid its recall. The results were found to pose severe problems for current theoretical ideas about the spacing effect.     

Effects of spacing repetitions on children's memory

Two experiments examined the effect of spacing repetitions within a word list on the free recall performance of elementary school children. In the first experiment, spacing repetitions facilitated recall, and the function relating recall of repeated items to the spacing between repetitions was the same throughout the age range investigated (first, third, and sixth graders). But, the function for these elementary school children reached asymptote at a much shorter spacing than the function typically reported for adults. The second experiment was designed to test an encoding variability explanation of spaced-repetition effects in elementary school children. Results for both third- and sixth-grade children were consistent with the hypothesis that differential encoding of repetitions facilitates performance and that spaced repetitions are remembered better because they are more likely to be differentially encoded. A theoretical framework was discussed that may be able to encompass both these results and another finding in the literature which indicates that differential encoding can sometimes impair rather than facilitate children's memory performance.     

Semantic organization of study materials has opposite effects on recognition and recall

It has been well established for several decades that semantic organization of study materials greatly enhances recall by facilitating access to information during retrieval. However, the effect of organization on recognition, and its relationship to the effect on recall, is in doubt. We report the first direct comparison of the effects of categorically organizing study lists on recognition, cued recall, and free recall. We found that whereas organization improved recall, it impaired recognition. Organization had a larger effect on free recall than on cued recall. Within the categorized lists, recall was superior for items highly associated with the category; the opposite was true of recognition. In recall, organization improved the proportion of categories recalled, but it lowered the proportion of items per category recalled. A simple framework for interpreting the dissociation is offered. Possible mechanisms underlying the detrimental effect of organization on memory and prospects for future research are briefly discussed.     

Scaling behavior in the temporal context model

The Temporal Context Model (TCM) postulates a distributed representation of temporal context that provides the cue for episodic recall tasks. TCM, coupled with the Luce Choice Rule for determining probability of recall, a conjunction referred to as TCMFR, is able to explain the existence of the long-term recency effect, as well as predicting the persistence of associative effects even with the inclusion of a delay between items. Here, quantitative predictions of TCMFR such as the magnitude of the delay interval is increased in continuous-distractor free recall are developed. The magnitude of the recency effect is operationally defined as the ratio of the probability of first recall (PFR) of the last list item to the PFR of the next-to-last item. Properties of associative effects are operationalized by using analogous measures derived from conditional response probability (CRP) curves. TCMFR predicts a decrease in recency with increasing delay. The rate of this decay and the qualitative pattern of change with increasing delay depend on the rate of contextual drift. For a range of values of the rate of contextual drift, TCMFR also predicts a transient increase in the recency effect as the length of the delay increases from zero. The model predicts that contiguity effects in free recall should follow a similar pattern, but that associative asymmetry, ubiquitously observed in free recall, should decay monotonically with increases in the delay interval.     

High-priority event instructions affect implicit and explicit memory tests

Previous work has shown that instructing subjects to give special priority to one target event in a list enhances recall for that event, but impairs recall for the events immediately preceding it (Tulving, 1969). We examined the benefit of high-priority instructions, and the retrograde amnesia for previous items, in three experiments that included two explicit tests of memory (free recall and cued recall with word-stem cues) and an implicit test (word-stem completion). Experiments 1 and 2 revealed a beneficial effect of high-priority instructions on memory for the target events in both free recall and primed word-stem completion. Retrograde amnesia for previous events was either absent (Experiment 1) or modest (Experiment 2) in free recall; however, no evidence for amnesia occurred on the implicit test. In Experiment 3, we asked if the benefit of high-priority instructions on the implicit test was due to contamination from intentional recollection, by employing the logic of the retrieval-intentionality criterion via a levels-of-processing manipulation. The results showed a beneficial effect of high-priority instructions on free recall, word-stem cued recall, and word-stem completion. Level of processing affected the two explicit tests, but not the implicit test, indicating that it induced incidental retrieval. We conclude that the benefit of high-priority instructions occurred on all three tests used in these experiments. In contrast, the phenomenon of retrograde amnesia occurred in free recall, but not in primed word-stem completion.     

Dissociative tendencies and memory performance on directed-forgetting tasks

The current article presents two studies that aimed to replicate DePrince and Freyd's (2001, 2004) studies demonstrating that high and low dissociators differentially recall neutral and trauma words under conditions of varying cognitive load. We did not find this effect. This lack of replication was apparent for both free recall and word recognition memory and in both studies. In effect, we found little evidence to support betrayal trauma theory, yet observed increased memory fallibility, as demonstrated by lower general recall and (in one study) commission errors, in high dissociators.     

Rehearsal strategies and the serial-position curve in immediate free recall of ordered items

Immediate free recall of random strings of 10 numbers was studied under four experimental conditions: as each number was presented, subjects either had to recall the previous number (Recall n-1), recall the number just presented (Recall n), read the number (Read aloud), or were silent (Free Recall). Overall recall was the same in all conditions. Recall and order of recall by serial-position changed systematically, with an increasing recency and decreasing primacy effect from Free Recall through Read Aloud and Recall n to Recall n-1. These changes in recall order and serial-position curves suggest that differential rehearsal of items is decreased by requiring retrieval during presentation.     

Social demand characteristics in children's and adults' eyewitness memory and suggestibility: the effect of different interviewers on free recall and recognition

Shortly after viewing a video of a theft, 5‐ and 7‐year‐old children and adults were interviewed with free recall and either misleading or unbiased‐leading questions. After a 2‐day delay, participants were interviewed with free recall and recognition questions administered by either the same or a different interviewer. Results from day 1 replicate previous findings with levels of recall and resistance to suggestibility increasing with age. Counter to predictions, correct recognition performance on day 2 was greater for some participants interviewed by the same as opposed to a different interviewer, and incorrect recognition was greater for all groups of participants for those interviewed by a different as opposed to the same interviewer. Results are discussed in terms of the role of context dependence on memory performance. Copyright © 2000 John Wiley & Sons, Ltd.     

Development of organization in recall: A stages-of-learning analysis

An experiment is reported in which the effects of taxonomic organization on 7-year-old and 11-year-old children's free and cued recall of two- and four-category lists were examined. The data were analyzed using a stages-of-learning model that simultaneously delivers estimates of the impact of these manipulations on storage and retrieval components of recall. The results indicated that for the Grade 2 children providing a category label at the time of recall primarily enhanced storage whereas increasing the number of categories primarily enhanced retrieval. For Grade 6 children, on the other hand, the use of category labels to cue recall primarily enhanced retrieval, whereas increasing the number of categories affected both storage and retrieval in free recall, but only retrieval in cued recall. In addition, while older children were superior to younger children at both storing and retrieving information, age differences at retrieval were generally larger than those at storage.