A deeper analysis of the spacing effect after “deep” encoding

The most common encoding strategies used by participants in word list studies include rehearsal and using the story mnemonic. Previous studies have suggested that with a rote-rehearsal strategy, mixed lists lead people to borrow rehearsal time from massed items and to give it to spaced items. Using rehearse-aloud methodologies, we demonstrated in Experiment 1 that the borrowing effect does not occur in the story mnemonic. However, the rates of rehearsal of individual items provided a good prediction of their subsequent recall rates, with spaced items being rehearsed more often in both mixed and pure lists. In Experiment 2, we demonstrated that creating "story links" between items enhanced recall, but it did not affect the magnitude of the spacing effect. These results suggest that a massed-item deficit in encoding may underlie the spacing effect in the story mnemonic.     

Directed forgetting and aging: the role of retrieval processes, processing speed, and proactive interference

The directed forgetting effect obtained with the item method is supposed to depend on both selective rehearsal of to-be-remembered (TBR) items and attentional inhibition of to-be-forgotten (TBF) items. In this study, we investigated the locus of the directed forgetting deficit in older adults by exploring the influence of recollection and familiarity-based retrieval processes on age-related differences in directed forgetting. Moreover, we explored the influence of processing speed, short-term memory capacity, thought suppression tendencies, and sensitivity to proactive interference on performance. The results indicated that older adults' directed forgetting difficulties are due to decreased recollection of TBR items, associated with increased automatic retrieval of TBF items. Moreover, processing speed and proactive interference appeared to be responsible for the decreased recall of TBR items.     

Proactive control of proactive interference using the method of loci

Proactive interferencebuilds up with exposure to multiple lists of similar items with a resulting reduction in recall. This study examined the effectiveness of using a proactive strategy of the method of loci to reduce proactive interference in a list recall paradigm of categorically similar words. While all participants reported using some form of strategy to recall list words, this study demonstrated that young adults were able to proactively use the method of loci after 25 min of instruction to reduce proactive interference as compared with other personal spontaneous strategies. The implications of this study are that top-down proactive strategies such as the method of loci can significantly reduce proactive interference, and that the use of image and sequence or location are especially useful in this regard.     

Directed Forgetting and Aging: The Role of Retrieval Processes,Processing Speed,and Proactive Interference

ABSTRACT

The directed forgetting effect obtained with the item method is supposed to depend on both selective rehearsal of to-be-remembered (TBR) items and attentional inhibition of to-be-forgotten (TBF) items. In this study, we investigated the locus of the directed forgetting deficit in older adults by exploring the influence of recollection and familiarity-based retrieval processes on age-related differences in directed forgetting. Moreover, we explored the influence of processing speed, short-term memory capacity, thought suppression tendencies, and sensitivity to proactive interference on performance. The results indicated that older adults' directed forgetting difficulties are due to decreased recollection of TBR items, associated with increased automatic retrieval of TBF items. Moreover, processing speed and proactive interference appeared to be responsible for the decreased recall of TBR items.     

Rehearsal dynamics in elementary school children

Several studies on free recall suggest that processes responsible for recall are analogous to processes responsible for rehearsal. In children, the relationship between cumulative rehearsal and recall performance has been proven to be critical; however, the locus of the effect of rehearsal is not yet fully understood. To unfold the mechanisms that come into play in an overt rehearsal free recall task, we assessed rehearsal and recall sequences in children between 8 and 10 years of age. These sequences give information about the context in which items are repeated and rearranged throughout the list and subsequently recalled. Rehearsal sequences consisted mainly of items from neighboring list positions in their original temporal order. The same characteristics were true for recall sequences. Qualitatively, order effects during study and recall did not differ over age groups. However, in older children who were using cumulative rehearsal more intensively, successive rehearsal and recall of items in their original order was more pronounced. Therefore, we suggest that a main feature of item rehearsal with regard to facilitating recall is the strengthening of interitem associations based on the temporal order within a list and that this characteristic develops with age.     

Delayed mnemonic benefits for a combined pegword–keyword strategy,time after time,rhyme after rhyme

The pegword method is an organizational mnemonic strategy that is often recommended for remembering ordered lists. However, are memorial benefits maintained over time when students learn several consecutive lists using the same 10 standard pegwords? Questions such as this have been raised about the delayed benefits of the technique, particularly when the pegword method is combined with elements of the familiar mnemonic keyword method. In two experiments in which we compared a combined pegword–keyword strategy with an own‐best‐method control condition after equating students' initial learning, we found consistent 2‐ and 5‐day‐delayed memory advantages for students reusing the combined mnemonic strategy with the same 10 pegwords. Our findings suggest that repeated use of this combined mnemonic approach benefits students' delayed memory for ordered lists of unfamiliar items. Copyright © 2010 John Wiley & Sons, Ltd.     

Proactive interference in immediate serial recall

Two experiments yielded significant inter-list proactive interference (PI) in immediate serial recall of nine-consonants lists. This argues against the assumption that intra-trial rehearsal is sufficiently powerful to prevent PI from occurring. In the first experiment PI proved to be more pronounced in the case of visually than of auditorily presented lists to the extent that the modality effect on the prerecent items could be completely attributed to PI. PI also enlarged the effect of output interference through reversed order recall. These findings were confirmed in the second experiment which also showed that the effect of PI persisted at a slower presentation rate, suggesting that the role of rehearsal in counteracting PI should not be overestimated. Implications of these results for current notions on short-term retention are discussed.     

The effects of item material on encoding strategies: Survival processing compared to the method of loci

When imagining being stranded in the grasslands of a foreign land without any basic survival material, participants have a magnificent memory for words rated according to their usefulness in this particular situation. Numerous studies could demonstrate that survival processing boosts memory performance more than other memory enhancing techniques. The method of loci is an old mnemonic strategy used to enhance serial recall. This method encompasses navigating mentally through a familiar environment and placing the to-be-remembered items in specific locations. In the later recall phase, the participant re-imagines walking through the environment, “looking” for the to-be-remembered items. In two studies, we compared the survival scenario with the method of loci and two different control conditions. In addition, we manipulated the used word-material on two different dimensions (imageability and relevance) to analyse its influences on the two methods. For words high in imageability, we found that memory performance in the survival condition is comparable to the method of loci. However, for words low in imageability the method of loci proved to be more effective than survival processing. Furthermore, we found that survival relevance has a high impact on the amount of the survival processing effect, even when imageability is low.     

Enhancement of 4-year-old children's memory span for phonologically similar and dissimilar word lists

Previous research suggests that preschool children are deficient in rehearsal and that stimulus list repetitions can improve their recall, presumably by substituting for the products of rehearsal. However, the previous research included interitem or postlist retention intervals of several seconds or more. We examined the utility of list repetitions with reference to an ordinary span task in which spoken words were presented 1 s apart for immediate recall. Lists with phonologically similar versus dissimilar items were included, to determine if the overall pattern of recall could be made more similar to what is ordinarily obtained in older children. Cumulative repetition was found to cause a moderate increase in both memory span and the phonological similarity effect. Other types of list repetition provided more insight into types of stimulus redundancy that were helpful (e.g., repeated serial order information) or not helpful (e.g., forced articulatory coding) to children attempting to recall spoken lists. The underlying mnemonic processes are discussed.     

Concerning the role of perceptual factors in the serial position effect

The experiment described here addresses itself to the serial position effect of recall, and in particular to the cause of primacy. Two of the three theories discussed here (selective rehearsal and proactive interference) postulate competition between items during the storage interval as a cause of primacy, acquisition being assumed to be equal for all items. The third theory (differential perceptual processing) places the locus of the effect prior to the storage stage, and does not hold interactions between items to be essential to the effect after encoding. The experiment used this distinction between the two classes of theories, storage of the whole presentation (and hence interactions during storage) not being required. Only one word from each list was recalled, and this item was indicated to S on presentation, thereby eliminating the necessity to attempt to encode all items. The storage-interaction theories predict no primacy for the recall of individual items in this experiment, but the initial member of the list was recalled more often than the third member. This example of primacy lends support to the argument that the trace strengths of items are not always equal immediately after presentation.     

Item Interference and Time Delays in Working Memory: Immediate Serial Recall

Limitations on immediate recall span have been related by some to temporal limitations of an articulatory rehearsal loop (Baddeley, 1986), and by others to retroactive interference from subsequent items (Lewandowsky & Murdock, 1989; Neath & Nairne, 1995). In the current study, the number of intervening items and retention delays were partially decoupled by varying presentation rate and materials sets. Recently, memory span effects often attributed to temporal limits in rehearsal were shown to be directly related to the output delays during the act of recall (Dosher & Ma, 1998). A functional model of working memory provides a framework within which to evaluate the relative contributions of item interference and retention delays in the accuracy of recall at each serial position. Output delays during recall and interference from items during study were the primary factors in limiting recall, with small additional effects of time delays during study.     

Proactive effects of memory in young and older adults: The role of change recollection

Age-related deficits in episodic memory are sometimes attributed to older adults being more susceptible to proactive interference. These deficits have been explained by impaired abilities to inhibit competing information and to recollect target information. In the present article, I propose that a change recollection deficit also contributes to age differences in proactive interference. Change recollection occurs when individuals can remember how information changed across episodes, and this counteracts proactive interference by preserving the temporal order of information. Three experiments were conducted to determine whether older adults are less likely to counteract proactive interference by recollecting change. Paired-associate learning paradigms with two lists of word pairs included pairs that repeated across lists, pairs that only appeared in List 2 (control items), and pairs with cues that repeated and responses that changed across lists. Young and older adults’ abilities to detect changed pairs in List 2 and to later recollect those changes at test were measured, along with cued recall of the List 2 responses and confidence in recall performance. Change recollection produced proactive facilitation in the recall of changed pairs, whereas the failure to recollect change resulted in proactive interference. Confidence judgments were sensitive to these effects. The critical finding was that older adults recollected change less than did young adults, and this partially explained older adults’ greater susceptibility to proactive interference. These findings have theoretical implications, showing that a change recollection deficit contributes to age-related deficits in episodic memory.     

Effects of talker variability on recall of spoken word lists

Three experiments were conducted to investigate recall of lists of words containing items spoken by either a single talker or by different talkers. In each experiment, recall of early list items was better for lists spoken by a single talker than for lists of the same words spoken by different talkers. The use of a memory preload procedure demonstrated that recall of visually presented preload digits was superior when the words in a subsequent list were spoken by a single talker than by different talkers. In addition, a retroactive interference task demonstrated that the effects of talker variability on the recall of early list items were not due to use of talker-specific acoustic cues in working memory at the time of recall. Taken together, the results suggest that word lists produced by different talkers require more processing resources in working memory than do lists produced by a single talker. The findings are discussed in terms of the role that active rehearsal plays in the transfer of spoken items into long-term memory and the factors that may affect the efficiency of rehearsal.     

Metamemories of memory researchers

In the present study, a metamemory questionnaire was completed by three groups of individuals: memory research psychologists who attended a small international convention on everyday memory processes in the aged, academic psychologists with a limited knowledge of the memory literature, and nonpsychologist college professors. There was little evidence that memory psychologists reported using strategies to remember things that were different from the strategies of other academics. The most used and most recommended technique for remembering was to write things down, followed by general internal mnemonic systems such as organization and rehearsal. The least used and least recommended strategies for all three groups were formal mnemonic systems, such as the peg-word system or the method of loci.     

Updating of working memory: Lingering bindings

Three experiments investigated proactive interference and proactive facilitation in a memory-updating paradigm. Participants remembered several letters or spatial patterns, distinguished by their spatial positions, and updated them by new stimuli up to 20 times per trial. Self-paced updating times were shorter when an item previously remembered and then replaced reappeared in the same location than when it reappeared in a different location. This effect demonstrates residual memory for no-longer-relevant bindings of items to locations. The effect increased with the number of items to be remembered. With one exception, updating times did not increase, and recall of final values did not decrease, over successive updating steps, thus providing little evidence for proactive interference building up cumulatively.     

Effects of lexical competition on immediate memory span for spoken words

Current theories and models of the structural organization of verbal short-term memory are primarily based on evidence obtained from manipulations of features inherent in the short-term traces of the presented stimuli, such as phonological similarity. In the present study, we investigated whether properties of the stimuli that are not inherent in the short-term traces of spoken words would affect performance in an immediate memory span task. We studied the lexical neighbourhood properties of the stimulus items, which are based on the structure and organization of words in the mental lexicon. The experiments manipulated lexical competition by varying the phonological neighbourhood structure (i.e., neighbourhood density and neighbourhood frequency) of the words on a test list while controlling for word frequency and intra-set phonological similarity (family size). Immediate memory span for spoken words was measured under repeated and nonrepeated sampling procedures. The results demonstrated that lexical competition only emerged when a nonrepeated sampling procedure was used and the participants had to access new words from their lexicons. These findings were not dependent on individual differences in short-term memory capacity. Additional results showed that the lexical competition effects did not interact with proactive interference. Analyses of error patterns indicated that item-type errors, but not positional errors, were influenced by the lexical attributes of the stimulus items. These results complement and extend previous findings that have argued for separate contributions of long-term knowledge and short-term memory rehearsal processes in immediate verbal serial recall tasks.     

List-strength effect: I. Data and discussion

Extra items added to a list cause memory for the other items to decrease (the list-length effect). In one of the present studies we show that strengthening (or weakening) some items on a list harms (helps) free recall of the remaining list items. This is termed the list-strength effect. However, in seven recognition studies the list-strength effect was either absent or negative. This held whether strengthening was accomplished by extra study time or extra repetitions. The seven studies used various means to control rehearsal strategies, thereby providing evidence against the possibility that the findings were due to redistribution of rehearsal or effort from stronger to weaker items within a list. Current models appear unable to predict these results. We suggest that different retrieval operations underlie recall and recognition, as in the SAM model of Gillund and Shiffrin (1984), which can be made to fit the results with certain relatively minor modifications.     

Auditory and visual serial position functions obey different laws

Rhesus monkeys were tested in serial probe recognition tasks with either travel slide pictures or natural sounds. Tests with four-item lists produced serial position functions that were essentially opposite in shape for the two modalities and changed in opposite ways with retention interval. For visual memory, the primacy effect grew and the recency effect dissipated with retention interval. Capuchin monkeys, humans, and pigeons showed similar results. For auditory memory with rhesus monkeys, the recency effect grew and the primacy effect dissipated with retention interval. These results taken together, along with results from rehearsal tests of monkeys and humans, implicate two passive memory processes with different time courses. Interference among items within auditory lists was manipulated by varying the time between items and categories of items. Interference across lists was manipulated by varying the item pool size and, hence, item repetitions. Changes in the auditory serial position functions indicated that proactive and retroactive interference may have been instrumental in these dynamically changing serial position functions. Implications for theories and models of memory are discussed.     

Influences of part-list cuing on different forms of episodic forgetting

Across 3 experiments, we examined the interplay of part-list cuing and forgetting, employing 3 different methods to induce episodic forgetting-list--method directed forgetting, context-dependent forgetting, and proactive interference. For each form of forgetting, participants were asked at test to recall the target items of a previously studied list in the presence or the absence of the list's remaining items serving as retrieval cues. We found such part-list cuing to amplify the forgetting in proactive interference but to diminish the forgetting in list-method directed forgetting and context-dependent forgetting. These results show that the effects of part-list cuing on forgotten memories depend critically on the circumstances surrounding the forgetting. If the forgetting reflects impaired access to the original encoding context, as has been suggested in list-method directed forgetting and context-dependent forgetting (but not in proactive interference), part-list cues improve access to forgotten memories; if the forgetting does not reflect such a contextual effect, no such beneficial effects emerge, and access to forgotten memories may even be impaired.