Forgetting the Unforgettable Through Conversation: Socially Shared Retrieval-Induced Forgetting of September 11 Memories

ABSTRACT— A speaker's selective recounting of memories shared with a listener will induce both the speaker and the listener to forget unmentioned, related material more than unmentioned, unrelated material. We extended this finding of within-individual and socially shared retrieval-induced forgetting to well-rehearsed, emotionally intense memories that are similar for the speaker and listener, but differ in specifics. A questionnaire probed participants' memory of the September 11 terrorist attacks. Questions and responses were grouped into category-exemplar structures. Then, participants selectively rehearsed their answers (using a structured interview in Experiment 1 and a joint recounting between pairs in Experiment 2 ). In subsequent recognition tests, response times yielded evidence of within-individual retrieval-induced forgetting and socially shared retrieval-induced forgetting. This result indicates that conversations can alter memories of speakers and listeners in similar ways, even when the memories differ. We discuss socially shared retrieval-induced forgetting as a mechanism for the formation of collective memories.     

Gone but not forgotten: the transient nature of retrieval-induced forgetting

Recent research has demonstrated that the act of remembering can prompt temporary forgetting or, more specifically, the inhibition of particular items in memory. Extending work of this kind, the present research investigated some possible boundary conditions of retrieval-induced forgetting. As expected, a critical determinant of temporary forgetting was the interval between guided retrieval practice and a final recall test. When these two phases were separated by 24 hr, retrieval-induced forgetting failed to emerge. When they occurred in the same testing session, however, retrieval practice prompted the inhibition of related items in memory (i.e., Experiment 1). A delay of 24 hr between the encoding of material and guided retrieval practice reduced but did not eliminate retrieval-induced forgetting (i.e., Experiment 2). These findings are considered in the wider context of adaptive forgetting.     

New evidence on the suggestibility of memory: the role of retrieval-induced forgetting in misinformation effects

Extending recent work that has demonstrated that the act of remembering can result in the inhibition of related items in memory, the present research examined whether retrieval-induced forgetting could provide a mechanism for explaining misinformation effects. Specifically, the authors found in their first study that the inhibition of critical items rendered the recollection of postevent information more likely in a subsequent test of memory. The authors established in their second study that when guided retrieval practice and final recall tests were separated by 24 hr, retrieval-induced forgetting failed to emerge and misinformation effects were absent. In contrast, a delay of 24 hr between initial encoding and guided retrieval practice produced not only retrieval-induced forgetting but also misinformation effects.     

社会分享型提取诱发遗忘的性别差异：来自关系动机的影响作用

社会互动提取任务中,说者的选择性提取会造成听者对相关内容的遗忘,这被称为社会分享型提取诱发遗忘。本研究基于关系动机的视角,分别考察女性组合和男性组合条件下,听者社会分享型提取诱发遗忘的表现特点。结果表明,女性组合中的听者在同性别说者在场的条件下,出现了社会分享型提取诱发遗忘;而男性组合中的听者在同性别说者在场的条件下,无该现象出现。以上结果为关系动机影响社会分享型提取诱发遗忘提供了实证证据。     

Forgetting in context: The effects of age, emotion, and social factors on retrieval-induced forgetting

Retrieval-induced forgetting (RIF) refers to the finding that selectively retrieving some information impairs subsequent memory for related but nonretrieved information. This occurs both for the individual doing the remembering (i.e., within-individual retrieval-induced forgetting: WI-RIF), as well as for individuals merely listening to those recollections (i.e., socially shared retrieval-induced forgetting: SS-RIF). In the present study, we examined how the contextual factors of age and emotion independently and interactively affect both WI-RIF and SS-RIF. The results indicated that both WI-RIF and SS-RIF occurred at equivalent levels, both for younger and older adults and for neutral and emotional information. However, we identified a boundary condition to this effect: People only exhibited SS-RIF when the speaker that they were listening to was of the same sex as themselves. Given that participants reported feeling closer to same-sex speakers, this suggests that people co-retrieve more, and therefore exhibit increased SS-RIF, with close others. In everyday life, these RIF effects should influence what information is remembered versus forgotten in individual and collective memories.     

On the role of item similarity in retrieval-induced forgetting

We report on two experiments designed to examine how the similarity of retrieval-practised and not-retrieval-practised items influences the amount of retrieval-induced forgetting. Participants studied categorised item lists with each category consisting of exemplars from two different semantic subcategories. Using both the retrieval practice paradigm (Experiment 1) and the output interference paradigm (Experiment 2) we found that the retrieval of a subset of the studied items impaired the subsequent recall of the nonpractised items if the two types of items were fairly dissimilar to each other (same category but different subcategory) but did not induce impairment if the two types of items were highly similar (same category and subcategory). These results indicate that a high degree of similarity of practised and nonpractised items can eliminate retrieval-induced forgetting. They also suggest that forgetting in the retrieval practice paradigm and forgetting in the output interference paradigm are mediated by the same mechanisms. The relation of the present results to other very recent findings about the role of item similarity in retrieval-induced forgetting in discussed.     

Retrieval-induced forgetting in implicit memory tests: The role of test awareness

Retrieval practice with particular items in memory may result in decreased recall of different, semantically related, items. This retrieval-induced forgetting effect has been demonstrated in studies using explicit memory tests. Anderson and Spellman (1995) have attributed retrieval-induced forgetting to inhibitory mechanisms. This hypothesis predicts similar effects in implicit memory tasks. In our first experiment, using Anderson and Spellman’s original paradigm, retrieval-induced forgetting was found using an explicit memory test with independent extralist retrieval cues. In our second experiment, using the same materials, retrieval-induced forgetting was also found using an implicit memory test with independent extralist retrieval cues, but only for participants who were aware of the relationship between the study and practice phase on the one hand, and the test phase of the experiment on the other. Thus, test awareness seems to mediate retrieval-induced forgetting in implicit memory tasks.     

Effects of repeated retrieval of central and peripheral details in complex emotional slides

Research has demonstrated that repeated retrieval enhances memory for practised verbal information, but undermines correct recall of unpractised related verbal information, a phenomenon known as retrieval-induced forgetting (RIF). This paper addresses the question of what happens with memory for unrehearsed aspects of an emotional picture when retrieval of other aspects of that picture is practised. In two experiments we investigated whether repeated retrieval of certain details of negative emotional slides undermines recall of unrehearsed details of such slides. In Experiment 1 retrieval of peripheral details was practised. The results demonstrated that recall for peripheral details was enhanced. However, correct recall of unpractised central details remained unaffected. Furthermore, retrieval practice did not alter the number of commission errors. Experiment 2 revealed that repeated retrieval of central details enhanced memory for these details. Although more commission errors were produced, again correct recall was not impaired for the unrehearsed central and peripheral details. This failure to find retrieval-induced forgetting effects for complex visual material is at odds with the RIF literature, and potential reasons for this are discussed. The data also extend previous studies in demonstrating that extensive retrieval can increase the number of commission errors.     

Accelerated relearning after retrieval-induced forgetting: the benefit of being forgotten

Research on retrieval-induced forgetting has demonstrated that retrieving some information from memory can cause the forgetting of other information in memory. Here, the authors report research on the relearning of items that have been subjected to retrieval-induced forgetting. Participants studied a list of category- exemplar pairs, underwent a series of retrieval-practice and relearning trials, and, finally, were tested on the initially studied pairs. The final recall of non-relearned items exhibited a cumulative effect of retrieval-induced forgetting such that the size of the effect increased with each block of retrieval practice. Of most interest, and very surprising from a common-sense standpoint, items that were relearned benefited more from that relearning if they had previously been forgotten. The results offer insights into the nature and durability of retrieval-induced forgetting and provide additional evidence that forgetting is an enabler--rather than a disabler--of future learning.     

From A to Z? Retrieval-induced forgetting of non-verbal information indicates how writing systems can shape memory organisation

We investigated retrieval-induced forgetting of motor sequences in samples of Chinese participants. Retrieval-induced forgetting occurs when selective retrieval of a subset of information stored in memory causes forgetting for the non-retrieved rest. This phenomenon critically depends on the organised storage of separate categories of memory representations. In studies with participants from a Western culture (Germany), a categorization in left- and right-hand movements previously had been supported by letter stimuli based on a spatial mental representation of the Roman alphabet. The same assignment of letters from the beginning or end of the alphabet to motor sequences performed either with the left- or the right-hand did not entail retrieval-induced forgetting in the present study, however (Experiment 1). In Experiment 2, visual features of displaying to-be-learned sequences additionally supported a distinction into left and right. In Experiment 3, learning trials provided verbal category labels. The occurrence of retrieval-induced forgetting in the latter two experiments suggests language-dependent organisation of non-verbal items in memory.     

情绪对提取诱发遗忘的影响

从学习材料的情绪性和提取过程的情绪状态两方面考察了情绪对提取诱发遗忘的影响。结果发现提取练习对情绪性与非情绪性材料引发了同等程度的遗忘;提取练习阶段,当被试处于正性或中性情绪状态下也会发生明显的提取诱发遗忘现象,而当被试处于负性情绪状态时,提取练习不会导致对未提取项目的遗忘。研究结果表明,学习材料的情绪性不影响提取诱发遗忘,而提取过程的情绪状态会对提取诱发遗忘产生影响,负性情绪状态可以消除提取诱发遗忘。     

How motor practice shapes memory: retrieval but not extra study can cause forgetting

We investigated the retrieval specificity of retrieval-induced forgetting (RIF) of motor sequences. In two experiments, participants learned sequential finger movements, each consisting of the movement of two fingers of either the left or the right hand. In the learning phase, these motor sequences were graphically presented and were to be learned as responses to simultaneously presented letter stimuli. Subsequently, participants selectively practiced half the items of one hand. A final recall test then assessed memory for all initially learned items. We contrasted different kinds of selective practice with each other. Whereas retrieval practice required retrieving motor sequences in response to letter stimuli from the learning phase, extra study was an extension of the learning phase, that is, participants performed motor sequences in response to the same animation graphic display as in the learning phase again accompanied by the letter stimulus. All practice conditions strengthened the practiced items, but only retrieval practice resulted in RIF. Thus, the strengthening of items through practice did not suffice to induce forgetting of related motor sequences. Retrieval was a necessary component for practice to shape memory for body movements by impairing the subsequent recall of motor sequences that were related to the practiced motor sequences.     

When remembering the past suppresses memory for future actions

Remembering planned actions at the correct time in the future is an integral component of prospective cognition. Recent studies on future remembering have led to suggestions that prospective cognition might be based on past experience. To test this hypothesis, we focused on retrieval-induced forgetting (RIF), which usually indicates that remembering past events suppresses memory for related but different past events. The current study assessed RIF in two kinds of event-based prospective memory (PM) tasks using either focal or non-focal cues for ongoing tasks. Participants studied six members from each of eight taxonomic categories and then practiced recalling three of the six members from four of the eight categories using category-stem cues. This retrieval practice suppressed the detection of non-practiced members of the practiced categories during the PM task with non-focal cues (Experiment 1) but not with focal cues (Experiment 2). The results suggest that recall of certain items inhibits the function of the others as PM cues, but only if the PM task does not largely share its processing with the ongoing task.     

The costs and benefits of testing text materials

Tests have been shown to improve the later recall of tested information, a result known as the testing effect. Tests, however, can also impair the later recall of related information, an effect known as retrieval-induced forgetting. Although retrieval-induced forgetting has been demonstrated using a wide variety of materials, recent work suggests that learning information in the context of a coherent text passage may afford protection from retrieval-induced forgetting. In four experiments we explored the conditions under which retrieval-induced forgetting does and does not occur with such materials. We found that two factors—the coherence of the to-be-learned material and the competitiveness of retrieval practice—are important in determining whether retrieval-induced forgetting does or does not occur. Furthermore, even if retrieval-induced forgetting does occur, having the opportunity to restudy the forgotten information can prevent that forgetting from persisting. Taken together, these findings provide greater understanding of the costs and benefits of testing text materials, with possible implications for the optimisation of testing as a tool for learning in educational contexts.     

The subjective experience of retrieval-induced forgetting

The objective was to examine whether the lower accessibility of studied items (Rp?) that follows retrieval practice with studied items from the same category (Rp+; retrieval-induced forgetting) is correctly monitored by our cognitive system. If monitored, lower confidence for Rp? items would be expected which, in turn, would allow the control of the retrieval-induced forgetting through the report option. In Experiment 1 the standard retrieval-practice paradigm with categorised word lists was followed by a recognition test with confidence rating and the option to report or withhold the answer. Accuracy showed retrieval-induced forgetting, but there were no differences in confidence. The report option did not affect retrieval-induced forgetting. The confidence–accuracy dissociation could be due to a correct monitoring of the retrieval-induced forgetting joined with a factor that incorrectly increases confidence for Rp? items. Familiarity with the practised category was proposed as this factor and tested in Experiment 2. Despite presenting the categories more times during the retrieval-practice phase to increase their familiarity, confidence ratings were unaffected. In conclusion, this research suggests that retrieval-induced forgetting was not monitored, giving rise to a confidence–accuracy dissociation.     

Feedback increases benefits but not costs of retrieval practice: Retrieval-induced forgetting is strength independent

We examined how the provision of feedback affected two separate effects of retrieval practice: strengthening of practiced information and forgetting of related, unpracticed information. Feedback substantially increased recall of retrieval-practiced items. This unsurprising result shows once again that restudy opportunities boost the benefits of testing. In contrast, retrieval-induced forgetting was unaffected by the manipulation and occurred in equal size with or without feedback. These findings demonstrate strength independence of retrieval-induced forgetting and thus support a theoretical account assuming that an inhibitory mechanism causes retrieval-induced forgetting. According to this theory, inhibition resolves competition that arises during retrieval attempts but is unrelated to the consequences of retrieval practice concerning practiced items. The present results match these assumptions and contradict the theoretical alternative that blocking by strengthened information might explain retrieval-induced forgetting. We discuss our findings against the background of previous studies.     

The role of retrieval practice in directed forgetting

Three experiments tested the possibility that retrieval-induced forgetting is responsible for directed forgetting with the list method. In Experiments 1 and 2, additional List 2 retrieval practice was given to determine whether this would increase directed forgetting. In Experiment 1 all items came from a single category, and in Experiment 2 unrelated words were used. In Experiment 3 additional List 2 study accompanied List 2 retrieval practice. There was no evidence that List 2 retrieval practice, with or without additional List 2 study, affected the magnitude of directed forgetting. It was argued that retrieval-induced forgetting could not account for these results. Accounts with greater viability include retrieval strategy disruption and a modified version of the dissociation hypothesis.     

Retrieval-induced forgetting in recall and recognition of thematically related and unrelated sentences

In three experiments, we assessed the effects of type of relation and memory test on retrieval-induced forgetting of facts. In Experiments 1 and 2, eight sets of four shared-subject sentences were presented for study. They were constructed so that half were thematically related and half were unrelated. A retrieval practice phase required participants to recall a subset of the studied sentences. In the final test, the participants were prompted to recall all the sentences (character cued in Experiment 1 and character plus stem cued in Experiment 2). The results showed that the retrieval-induced forgetting (RIF) effect was similar for thematically related and unrelated sentences, indicating that the presence of episodic relations among the sentences was sufficient to produce the effect. In Experiment 3, a recognition task was introduced and the RIF effect emerged in accuracy as well as in latency measures. The presence of this effect with item-specific cues is difficult to accommodate for noninhibitory theories of retrieval.     

自我与提取诱发遗忘现象

考察了提取诱发遗忘现象在自我参照、母亲参照和他人参照加工条件下的不同表现,结果发现在前两种加工条件下都没有出现提取诱发的遗忘,而他人参照条件下则表现有这种遗忘,由此以提取诱发遗忘研究的实验范式证明了中国被试中自我参照加工与母亲参照加工相对于一般他人参照加工的优势。这一结果表明,对于中国被试来说,自我参照加工和母亲参照加工任务不仅可能会在总回忆量方面高于他人参照加工,而且经过这两类加工的材料在提取过程中不会形成对相关材料的抑制。另外,实验结果还说明母亲参照加工对于中国被试来说是提取诱发遗忘的一种边界条件。