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.     

The role of detection and recollection of change in list discrimination

In two experiments, we examined the importance of the detection and recollection of change for list discrimination. Two lists of pairs were presented, with the right-hand member being changed between lists for some pairs. Participants in Experiment 1 were instructed to explicitly indicate when they detected a change between pairs during the presentation of List 2, whereas participants in Experiment 2 were not instructed to do so. At the time of test, participants in both experiments were presented with a pair and asked whether it had been presented in List 2. Next, recollection of change was measured by asking whether the right-hand member of the pair was changed between the lists. The results from Experiment 1 revealed high correspondence between the detection of change during the presentation of List 2 and the recollection of change at the time of test. Consequently, change recollection at test can serve as a measure of earlier change detection, in combination with access to memory for change at the time of test. In both experiments, as compared to control conditions, proactive facilitation in list discrimination was observed when change was recollected, whereas proactive interference was observed when change was not recollected. These results were interpreted as showing that recursive reminding—bringing a List 1 pair to mind during the presentation of its changed List 2 pair—embeds memory for the earlier event into memory for the later event, and doing so preserves information about list membership.     

Reminders can enhance or impair episodic memory updating: a memory-for-change perspective

ABSTRACT

The Memory-for-Change framework proposes that retrieving episodic memories can facilitate new learning when changes between existing memories and new information are integrated during encoding and later recollected. Four experiments examined whether reminders could improve memory updating and enhance new learning. Participants studied two study lists of word pairs and were given a cued recall test on responses from both lists. Reminders of List 1 words pairs (A-B) appeared immediately before List 2 words pairs that included repeated cues and changed responses (A-D). Across experiments, we varied the types of reminders to determine whether differences in their effectiveness as retrieval cues would influence memory for the list membership of responses. We found that presenting intact reminders (cue-response) enhanced the memory benefits associated with recollection-based retrieval of changes relative to when no reminders appeared and when partial reminders (cue-only) appeared with and without feedback. Importantly, cue-response reminders benefitted memory when they were recognised in List 2 and when changes were later recollected. This suggests that integrative encoding can be facilitated when substantial environmental support is available to cue retrieval of existing memories. These findings have practical implications for understanding which reminders best aid the correction of memories for inaccurate information.     

Unitization mitigates interference by intrinsic negative emotion in familiarity and recollection of associative memory: Electrophysiological evidence

Emotion exerts varied influences on memory. While task-relevant item memory is often enhanced by emotion, associative memory is generally impaired. Unitization is known to improve associative memory, but its effects and mechanisms in protecting associative memory from emotional interference are rather obscure. The current study investigated associative memory by employing experimental manipulation of unitization (vs. nonunitization) encoding strategy and stimulus emotion (neutral, intrinsic negative, and extrinsic negative), combined with event-related potential (ERP) signatures of familiarity (FN400 old/new effects) and recollection (parietal late positive component/LPC old/new effects) in memory recognition. Both behavioral and ERP indices of associative recognition from the nonunitization group confirmed emotional interference in associative memory. Importantly, it was primarily intrinsic (vs. extrinsic) emotion that impeded associative memory. Unitization encoding improved memory performance in general, accompanied by enhanced recollection process and induction of familiarity process, which is typically not involved in associative memory recognition and was indeed absent in the nonunitization group. Importantly, unitization helped to preserve behavioral performance (specifically, response speed though not recognition strength) from interference by intrinsic emotion while largely reversed the detriment of intrinsic emotion on ERP indices of familiarity and recollection processes. Interestingly, a synergy between intrinsic emotion and unitization encoding was observed, which could underpin the facilitation of familiarity process in associative recognition of emotional pairs. Overall, current findings highlight interference by intrinsic emotion in associative memory, which is nonetheless responsive to mitigation by unitization encoding.     

Interference in memory for multiple contexts

Remembering that an item occurred in several different lists is formulated here in terms of retrieval of corresponding list tags associated to the item. Therefore, associative interference should operate upon remembering the several list contexts in which an item appeared. Experimental Ss studied four (or five) overlapping lists of 16 words, sampled from a master set of 32 words, with a given word exemplifying one of the 2 4 (or 2s 5 ) possible sequences of appearances and nonappearances over the four (or five) lists. Later Ss rated from memory for each word and for each list whether that word had occurred in that list. After correcting for interlist generalization effects, indices of discriminative memory revealed strong proactive interference and weaker retroactive interference. Discriminative memory that an item occurred in a given list was poorer the more prior or more subsequent lists in which that item had also occurred. Thus, list differentiation appears explicable in terms of item-specific associative interference.     

Retrieval during learning facilitates subsequent memory encoding

In multiple-list learning, retrieval during learning has been suggested to improve recall of the single lists by enhancing list discrimination and, at test, reducing interference. Using electrophysiological, oscillatory measures of brain activity, we examined to what extent retrieval during learning facilitates list encoding. Subjects studied 5 lists of items in anticipation of a final cumulative recall test and did either a retrieval or a no-retrieval task between study of the lists. Retrieval was from episodic memory (recall of the previous list), semantic memory (generation of exemplars from an unrelated category), or short-term memory (2-back task). Behaviorally, all 3 forms of retrieval enhanced recall of both previously and subsequently studied lists. Physiologically, the results showed an increase of alpha power (8-14 Hz) from List 1 to List 5 encoding when no retrieval activities were interpolated but no such increase when any of the 3 retrieval activities occurred. Brain-behavior correlations showed that alpha-power dynamics from List 1 to List 5 encoding predicted subsequent recall performance. The results suggest that, without intermittent retrieval, encoding becomes ineffective across lists. In contrast, with intermittent retrieval, there is a reset of the encoding process for each single list that makes encoding of later lists as effective as encoding of early lists.     

On the importance of looking back: The role of recursive remindings in recency judgments and cued recall

Suppose that you were asked which of two movies you had most recently seen. The results of the experiments reported here suggest that your answer would be more accurate if, when viewing the later movie, you were reminded of the earlier one. In the present experiments, we investigated the role of remindings in recency judgments and cued-recall performance. We did this by presenting a list composed of two instances from each of several different categories and later asking participants to select (Exp. 1) or to recall (Exp. 2) the more recently presented instance. Reminding was manipulated by varying instructions to look back over memory of earlier instances during the presentation of later instances. As compared to a control condition, cued-recall performance revealed facilitation effects when remindings occurred and were later recollected, but interference effects in their absence. The effects of reminding on recency judgments paralleled those on cued recall of more recently presented instances. We interpret these results as showing that reminding produces a recursive representation that embeds memory for an earlier-presented category instance into that of a later-presented one and, thereby, preserves their temporal order. Large individual differences in the probabilities of remindings and of their later recollection were observed. The widespread importance of recursive reminding for theory and for applied purposes is discussed.     

Recollective Experience During Recognition of Emotional Words in Clinical Depression

Earlier work has shown that free recall tasks produce a robust mood-congruent memory effect in depression, whereas recognition tasks produce heterogeneous results. This study aimed to further investigate recognition memory for positive, negative and neutral words in depressed patients and matched comparison participants with the Remember/Know/Guess procedure for assessing recollection and familiarity. No mood-congruent memory bias effect was detected in discrimination abilities. However, depressed patients recollected (more Remember responses) more negative than positive or neutral words, whereas comparison participants recollected more positive than neutral words. No mood-congruent pattern was evidenced for Know responses. However, the depressed patients responded to fewer words overall with Know responses than the comparison participants. These results suggest that the mood-congruent memory pattern in depressed patients is related to conscious recollection rather than to familiarity. Attentional biases toward negative words and elaboration processes and/or encoding in reference to the self may contribute to these findings.     

Probabilistic retroactive interference: the role of accessibility bias in interference effects

Probabilistic retroactive interference (RI) refers to the interfering effects of intermixing presentations of an earlier studied response (A-B) with presentations of a competing response (A-D). As an example, for a 2/3 condition, a cue word was presented with its earlier studied response twice and its competing response once during the interference phase. Performance on direct and indirect tests of memory for earlier studied responses was combined to reveal dissociations between effects on recollection and accessibility bias. Manipulating probabilistic RI influenced accessibility bias but left recollection unchanged. Effects of probabilistic RI were compared with effects of traditional, nonprobabilistic RI. The authors contrast their dual-process model with traditional accounts of RI and discuss the importance of distinguishing between recollection and accessibility bias for understanding interference effects.     

Proactive interference, accessibility bias, and process dissociations: valid subjective reports of memory

Proactive interference was assessed with a variant of the process-dissociation procedure, which separates effects of habit (accessibility bias) and recollection (discriminability). In three cued-recall experiments, proactive interference was shown to be an effect of bias rather than an effect on actual remembering. Divided attention, age, and study duration selectively influenced the recollection parameter, whereas training probability selectively influenced the habit parameter. Furthermore, in Experiments 2 and 3, subjective reports of remembering were highly correlated with, and nearly identical to, objective estimates of recollection gained from the process-dissociation procedure. The authors discuss the relevance of the results to theories of proactive interference and argue that older adults' greater susceptibility to interference effects is sometimes caused by an inability to recollect rather than by an inability to inhibit a preponderant response.     

Conceptual combinations and relational contexts in free association and in priming in lexical decision and naming

Words known to have strong associates of a particular relational type were embedded in lists of other words with relations of the same type or in lists of words with relations of a different type (e.g.close-far in a list of other opposite pairs or in a list of synonym pairs). In free association, the probability of a response consistent with the relational context was higher than the probability of a response inconsistent with the context. In lexical decision and naming, significant priming was obtained for related pairs of words only when their relation was consistent with the relational context of the list in which they were embedded. The priming effects were obtained when the stimulus onset asynchrony between prime and target words was short (250 msec for lexical decision and 300 msec for naming), indicating that the effects were due to automatic retrieval processes. These findings point to the importance of the particular relations between words in the retrieval of information from memory, an aspect of processing overlooked by current memory models.     

Disjunction and conjunction fallacies in episodic memory

It has recently been found that episodic memory displays analogues of the well-known disjunction and conjunction fallacies of probability judgement. The aim of the present research was, for the first time, to study these memory fallacies together under the same conditions, and test theoretical predictions about the reasons for each. The focus was on predictions about the influence of semantic gist, target versus context recollection, and proactive versus retroactive interference. Disjunction and conjunction fallacies increased in conditions in which subjects were able to form semantic connections among list words. In addition, disjunction fallacies were increased by manipulations that minimised proactive interference, whereas conjunction fallacies were increased by manipulations that minimised retroactive interference. That pattern suggests that disjunction fallacies are more dependent on target recollection, whereas conjunction fallacies are more dependent on context recollection.     

The role of horizontal categorization in retroactive and proactive interference

Four paired-associate experiments with a total N of 291 participants investigated the effects of horizontal categorization on retroactive and proactive interference. (Exclusively) horizontal categorization means that unique categorical relationships hold across the A-B and A-C stimulus-response pairs of successive word lists (e.g., fruit--pear, river--Thames, in list 1; and fruit--plum, river--Wolga, in list 2). Experiment 1 found no significant amounts of interference with this type of list organization. However, strong interference arose with the same materials when the categorical structure was destroyed in Experiment 2. A third experiment contrasted two alternative explanations for these results, and Experiment 4 replicated the effect of horizontal categorization (vs. no categorical relationship) in a within-participants design. The results of the four experiments largely fit with a response competition explanation proposed by Bower, Thompson-Schill, and Tulving (1994), adapted to the within-participants designs used here. Overall, the present findings add to a body of evidence demonstrating limits to retroactive and proactive interference.     

Mechanisms of inferential order judgments in humans (Homo sapiens) and rhesus monkeys (Macaca mulatta)

If A > B, and B > C, it follows logically that A > C. The process of reaching that conclusion is called transitive inference (TI). Several mechanisms have been offered to explain transitive performance. Scanning models claim that the list is scanned from the ends of the list inward until a match is found. Positional discrimination models claim that positional uncertainty accounts for accuracy and reaction time patterns. In Experiment 1, we trained rhesus monkeys (Macaca mulatta) and humans (Homo sapiens) on adjacent pairs (e.g., AB, BC, CD, DE, EF) and tested them with previously untrained nonadjacent pairs (e.g., BD). In Experiment 2, we trained a second list and tested with nonadjacent pairs selected between lists (e.g., B from List 1, D from List 2). We then introduced associative competition between adjacent items in Experiment 3 by training 2 items per position (e.g., B?C?, B?C?) before testing with untrained nonadjacent items. In all 3 experiments, humans and monkeys showed distance effects in which accuracy increased, and reaction time decreased, as the distance between items in each pair increased (e.g., BD vs. BE). In Experiment 4, we trained adjacent pairs with separate 9- and 5-item lists. We then tested with nonadjacent pairs selected between lists to determine whether list items were chosen according to their absolute position (e.g., D, 5-item list > E, 9-item list), or their relative position (e.g., D, 5-item list < E, 9-item list). Both monkeys' and humans' choices were most consistent with a relative positional organization.     

Recollective performance advantages for implicit memory tasks

A commonly held assumption is that processes underlying explicit and implicit memory are distinct. Recent evidence, however, suggests that they may interact more than previously believed. Using the remember–know procedure the current study examines the relation between recollection, a process thought to be exclusive to explicit memory, and performance on two implicit memory tasks, lexical decision and word stem completion. We found that, for both implicit tasks, words that were recollected were associated with greater priming effects than were words given a subsequent familiarity rating or words that had been studied but were not recognised (misses). Broadly, our results suggest that non-voluntary processes underlying explicit memory also benefit priming, a measure of implicit memory. More specifically, given that this benefit was due to a particular aspect of explicit memory (recollection), these results are consistent with some strength models of memory and with Moscovitch's (2008) proposal that recollection is a two-stage process, one rapid and unconscious and the other more effortful and conscious.     

The list strength effect: A contextual competition account

Research on the list strength effect (LSE) has shown that learning some words on a list more strongly than others impairs memory for the weakly learned words when tested with a recall task. Norman (2002) demonstrated that the LSE also occurs within the recollection process of a recognition test. In this study, a mechanistic dual-process account of the LSE was tested that simultaneously makes predictions concerning additional sources of context in interference effects. In two experiments, we attempted to replicate Norman's (2002) findings and provide the basis for our modeling efforts. We found evidence for a recollection LSE in raw measures of responding, with memory performance also benefiting from reinstatement of perceptual characteristics at test. However, large differences in the hits between the lists were accompanied by small differences in false alarms, such that when d' is calculated, differences between the lists are not significant. We propose an account of the LSE whereby the actual effect of competition between items on the list is small, although present, and difficult to distinguish from large effects of bias due to the strength manipulations. We argue that our findings provide support for a mechanistic explanation of LSE that is based on competition of source activation and changes in the thresholds for responses.     

Experience with proactive interference diminishes its effects: mechanisms of change

In three experiments, we examined the mechanisms by which prior experience with proactive interference (PI) diminished its effects. Cued recall tasks conforming to an A–B, A–D paradigm were used to induce PI effects. Experiment 1 showed that reduced PI was not due to a reduction in attention to the source of PI. Experiment 2 revealed that participants’ awareness of PI effects on memory performance increased with experience, resulting in a shift in encoding processes. Experiment 3 demonstrated that changes in encoding provided additional support for recollection that further enhanced participants’ ability to constrain their retrieval processing to the appropriate source of information at the time of test. These results can be interpreted as showing that experience with PI enhances awareness of its effects and allows individuals to adjust their learning and retrieval strategies to compensate for such effects.     

Sleep's function in the spontaneous recovery and consolidation of memories

Building on 2 previous studies (B. R. Ekstrand, 1967; B. R. Ekstrand, M. J. Sullivan, D. F. Parker, & J. N. West, 1971), the authors present 2 experiments that were aimed at characterizing the role of retroactive interference in sleep-associated declarative memory consolidation. Using an A-B, A-C paradigm with lists of word pairs in Experiment 1, the authors showed that sleep provides recovery from retroactive interference induced at encoding, whereas no such recovery was seen in several wake control conditions. Noninterfering word-pair lists were used in Experiment 2 (A-B, C-D). Sleeping after learning, in comparison with waking after learning, enhanced retention of both lists to a similar extent when encoding was less intense because of less list repetition and briefer word-pair presentations. With intense encoding, sleep-associated improvements were not seen for either list. In combination, the results indicate that the benefit of sleep for declarative memory consolidation is greater for weaker associations, regardless of whether weak associations result from retroactive interference or poor encoding.     

Effects of repetition on associative recognition in young and older adults: item and associative strengthening

Young and older adults studied word pairs and later discriminated studied pairs from various types of foils including recombined word-pairs and foil pairs containing one or two previously unstudied words. We manipulated how many times a specific word pair was repeated (1 or 5) and how many different words were associated with a given word (1 or 5) to tease apart the effects of item familiarity from recollection of the association. Rather than making simple old/new judgments, subjects chose one of five responses: (a) Old-Old (original), (b) Old-Old (rearranged), (c) Old-New, (d) New-Old, (e) New-New. Veridical recollection was impaired in old age in all memory conditions. There was evidence for a higher rate of false recollection of rearranged pairs following exact repetition of study pairs in older but not younger adults. In contrast, older adults were not more susceptible to interference than young adults when one or both words of the pair had multiple competing associates. Older adults were just as able as young adults to use item familiarity to recognize which word of a foil was old. This pattern suggests that recollection problems in advanced age are because of a deficit in older adults' formation or retrieval of new associations in memory. A modeling simulation provided good fits to these data and offers a mechanistic explanation based on an age-related reduction of working memory.     

Retroactive and proactive interference effects in dual learning of blissymbolics and manual sign

Nonspeech systems can be either aided or unaided. Each system possesses its unique learning and memory characteristics. One instructional strategy designed to give learners the advantages of both systems is dual instruction in aided and unaided communication. One problem with this approach, however, might be that of retroactive and proactive interference in learning and memory. The current experiment investigated whether dual instruction in Blissymbolics and manual (ASL) sign would lead to retroactive and proactive interference. Lists of sign/symbol referents in the two systems were taught, to nonhandicapped adults in a controlled setting. No effects of retroactive or proactive interference were found. Additionally, a proactive facilitation effect was found for immediate retention. Results are discussed in terms of the nature of the task, the learning memory attributes of the nonspeech systems, and the effects of sign/symbol translucency.