The roles of delay and retroactive interference in retrieval-induced forgetting

When subjects study items from different categories and then repeatedly retrieve some of the items from some of the categories, retrieval practice typically improves recall of the practiced items but impairs recall of related but unpracticed items, relative to control items from unpracticed categories. Here, we report the results of three experiments, in which we examined practiced and unpracticed items’ delay-induced forgetting (Exp. 1) and their susceptibility to retroactive interference (Exps. 2 and 3). Control items showed the expected memory impairment after longer delay between practice and test and in the presence of retroactive interference. In contrast, both the practiced and the related unpracticed items showed hardly any forgetting under these conditions. The findings are consistent with the results from recent testing-effect studies, which have reported reduced delay-induced forgetting and reduced susceptibility to interference for retrieval-practiced items, and generalize the results to related unpracticed items. The findings are discussed with respect to the inhibitory and noninhibitory accounts of retrieval-induced forgetting, as well as the possible role of selective segregation processes, which may be induced by retrieval practice.     

Retrieval-induced forgetting: Dynamic effects between retrieval and restudy trials when practice is mixed

Results from numerous previous studies suggest that when subjects study items from different categories and then repeatedly retrieve, or restudy, some of the items from some of the categories, repeated retrieval, but not repeated study, induces forgetting of related unpracticed items. We investigated in two experiments whether such effects of pure retrieval and pure study practice generalize to mixed practice—that is, when retrieval and restudy trials are randomly interleaved within a single experimental block. Experiment 1 employed cued recall; Experiment 2 employed item recognition testing. In both experiments, pure repeated retrieval, but not pure repeated study, caused forgetting of related unpracticed items, which is consistent with the prior work. In contrast, with mixed practice, both retrieval and restudy induced forgetting. Thus, whereas retrieval caused forgetting regardless of practice mode, restudy caused forgetting with mixed practice, but not with pure practice. The finding provides first evidence for dynamic effects between retrieval and restudy trials when practice is mixed. It is consistent with the view that, with mixed practice, subjects engage in more retrieval during restudy trials, so that restudy trials may trigger similar processes as retrieval trials and, thus, induce forgetting of related, not restudied, items.     

Episodic generation can cause semantic forgetting: Retrieval-induced forgetting of false memories

In two experiments, we tested whether false recognition and false recall were prone to retrieval-induced forgetting, using the retrieval practice paradigm (Anderson, Bjork, & Bjork, 1994). Participants encoded lists of cue-target word pairs associated with a nonpresented, critical theme word and then engaged in retrieval practice for half of the word pairs from half of the lists. As expected, unpracticed targets from practiced lists were recognized (Experiment 1) and recalled (Experiment 2) less well than those from unpracticed lists. In addition, false recognition and false recall of critical items associated with practiced lists was lower than false recognition and false recall of items associated with unpracticed lists. We argue that false memories are prone to inhibitory mechanisms engendered by the retrieval practice paradigm. The results are consistent with the claim that semantically activated critical themes interfere with the episodic retrieval of list words and that inhibition decreases the activation level of these interfering memory representations during retrieval practice.     

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.     

No retrieval-induced forgetting using item-specific independent cues: evidence against a general inhibitory account

Retrieval practice with particular items from memory can impair the recall of related items on a later memory test. This retrieval-induced forgetting effect has been ascribed to inhibitory processes (M. C. Anderson & B. A. Spellman, 1995). A critical finding that distinguishes inhibitory from interference explanations is that forgetting is found with independent (or extralist) cues. In 4 experiments, the authors tested whether the forgetting effect is cue-independent. Forgetting was investigated for both studied and unstudied semantically related items. Retrieval-induced forgetting was not found using item-specific independent cues for either studied or unstudied items. However, forgetting was found for both item types when studied categories were used as cues. These results are not in line with a general inhibitory account, because this account predicts retrieval-induced forgetting with independent cues. Interference and context-specific inhibition are discussed as possible explanations for the data.     

Retrieval-induced forgetting of negative stimuli: The role of emotional intensity

Repeatedly retrieving a subset of previously studied items can cause forgetting of related non-retrieved material. We examined whether such retrieval-induced forgetting holds also for negative material. Participants studied neutral and negative stimuli and then repeatedly retrieved a subset of the neutral material. Later, a recall test was conducted in which participants were asked to recall all previously studied items. On average, retrieval practice on the neutral items caused the same amount of forgetting for neutral and negative items, indicating that the emotionality of material does not affect retrieval-induced forgetting. More detailed analysis, however, revealed that the forgetting of negative items decreased with both the emotional intensity of a negative item and the dispositional negative affectivity of a participant. The decreases in retrieval-induced forgetting may have been driven by item-specific processing of material, which is known to be enhanced for highly negative stimuli and participants high in dispositional negative affectivity and to reduce or even eliminate retrieval-induced forgetting.     

Retrieval practice can eliminate list method directed forgetting

It has recently been shown that retrieval practice can reduce memories’ susceptibility to interference, like retroactive and proactive interference. In this study, we therefore examined whether retrieval practice can also reduce list method directed forgetting, a form of intentional forgetting that presupposes interference. In each of two experiments, subjects successively studied two lists of items. After studying each single list, subjects restudied the list items to enhance learning, or they were asked to recall the items. Following restudy or retrieval practice of list 1 items, subjects were cued to either forget the list or remember it for an upcoming final test. Experiment 1 employed a free-recall and Experiment 1 a cued-recall procedure on the final memory test. In both experiments, directed forgetting was present in the restudy condition but was absent in the retrieval-practice condition, indicating that retrieval practice can reduce or even eliminate this form of forgetting. The results are consistent with the view that retrieval practice enhances list segregation processes. Such processes may reduce interference between lists and thus reduce directed forgetting.     

A strategy disruption component to retrieval-induced forgetting

Retrieval-induced forgetting refers to a paradoxical occurrence wherein the act of remembering some material disrupts the retrieval of other, related material (see, e.g., M. C. Anderson, R. A. Bjork, & E. L. Bjork, 1994). This effect is generally accounted for in terms of inhibitory processes. Across three experiments, we test the inhibitory account of retrieval-induced forgetting, as well as whether there may be a strategy disruption component to the effect. In our first two experiments, we manipulate which items individuals are cued to recall during retrieval practice and demonstrate that retrieval-induced forgetting can be neutralized when those items do not interfere with the individual's retrieval strategy. In the third experiment, we confirm this finding with a different set of stimuli. These results are inconsistent with a purely inhibitory account of retrieval-induced forgetting, and we discuss implications for inhibition theory and strategy disruption in light of these and other findings.     

Assessing the inhibitory account of retrieval-induced forgetting with implicit-memory tests

Five experiments examined whether retrieval-induced-forgetting effects are observed for implicit tests of memory. In each experiment participants first studied category-exemplar paired associates, then practiced retrieval for a subset of items from a subset of categories before finally completing memory tests for all the studied items. In standard fashion, inhibition was measured as the performance difference of unpracticed items from practiced categories and unpracticed items from unpracticed categories. Across the 5 experiments poorer performance for unpracticed items was seen in conceptual implicit memory (category generation and category matching) but not in perceptual implicit memory (stem completion, perceptual identification). Thus, retrieval-induced-forgetting effects are limited to tests of conceptual memory.     

Noncompetitive retrieval practice causes retrieval-induced forgetting in cued recall but not in recognition

Retrieving a subset of learned items can lead to the forgetting of related items. Such retrieval-induced forgetting (RIF) can be explained by the inhibition of irrelevant items in order to overcome retrieval competition when the target item is retrieved. According to the retrieval inhibition account, such retrieval competition is a necessary condition for RIF. However, research has indicated that noncompetitive retrieval practice can also cause RIF by strengthening cue–item associations. According to the strength-dependent competition account, the strengthened items interfere with the retrieval of weaker items, resulting in impaired recall of weaker items in the final memory test. The aim of this study was to replicate RIF caused by noncompetitive retrieval practice and to determine whether this forgetting is also observed in recognition tests. In the context of RIF, it has been assumed that recognition tests circumvent interference and, therefore, should not be sensitive to forgetting due to strength-dependent competition. However, this has not been empirically tested, and it has been suggested that participants may reinstate learned cues as retrieval aids during the final test. In the present experiments, competitive practice or noncompetitive practice was followed by either final cued-recall tests or recognition tests. In cued-recall tests, RIF was observed in both competitive and noncompetitive conditions. However, in recognition tests, RIF was observed only in the competitive condition and was absent in the noncompetitive condition. The result underscores the contribution of strength-dependent competition to RIF. However, recognition tests seem to be a reliable way of distinguishing between RIF due to retrieval inhibition or strength-dependent competition.     

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。     

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, delay, and sleep

Retrieval-induced forgetting (RIF) refers to the finding that retrieval of a subset of previously studied material can cause forgetting of related unpractised material. Prior work on the role of delay between practice and test for RIF reported mixed results. Whereas some studies found RIF to be a relatively transient phenomenon, others found RIF to persist over time. We examined whether the persistence of RIF can depend on whether wakefulness or sleep follows retrieval practice. We employed a variant of the retrieval-practice paradigm with short (20 minutes) and long (12 hours) delay conditions. In all conditions participants studied a perceptually categorised list followed by retrieval practice on some of the items from some of the categories. Participants studied and practised the material in the morning or the evening. RIF was present in the short-delay conditions, and it was present in the long-delay condition if the delay included nocturnal sleep; if the long delay was filled with diurnal wakefulness, RIF was absent. Results show that whether delay eliminates RIF or not can depend on whether sleep or wake follows retrieval practice. Connections of the results to recent findings about the role of delay and sleep for RIF are discussed.     

Retrieval-induced forgetting,delay, and sleep

Retrieval-induced forgetting (RIF) refers to the finding that retrieval of a subset of previously studied material can cause forgetting of related unpractised material. Prior work on the role of delay between practice and test for RIF reported mixed results. Whereas some studies found RIF to be a relatively transient phenomenon, others found RIF to persist over time. We examined whether the persistence of RIF can depend on whether wakefulness or sleep follows retrieval practice. We employed a variant of the retrieval-practice paradigm with short (20 minutes) and long (12 hours) delay conditions. In all conditions participants studied a perceptually categorised list followed by retrieval practice on some of the items from some of the categories. Participants studied and practised the material in the morning or the evening. RIF was present in the short-delay conditions, and it was present in the long-delay condition if the delay included nocturnal sleep; if the long delay was filled with diurnal wakefulness, RIF was absent. Results show that whether delay eliminates RIF or not can depend on whether sleep or wake follows retrieval practice. Connections of the results to recent findings about the role of delay and sleep for RIF are discussed.     

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.     

定向遗忘的编码加工机制

有目的的遗忘(定向遗忘)需要耗费认知努力吗?有研究发现, 定向遗忘可能是被动衰减的结果, 即F项目(需要遗忘的项目)未获得有效复述是选择性复述了R项目(需要记住的项目)造成的, 这一加工过程不需要认知努力; 但也有研究表明, 定向遗忘过程可能是遗忘线索诱发的对记忆加工的主动抑制, 需要耗费认知努力, 脑认知研究中发现的前额叶ERPs成分为这一机制提供了证据。还有一种观点认为, 定向遗忘编码过程可能同时包含主动抑制与被动衰减, 但是尚不清楚两种加工机制相互作用的方式。为进一步澄清定向遗忘编码阶段的认知机制, 未来研究需要将非认知因素纳入考察, 并关注不同人群的定向遗忘特征, 在此基础上尝试解决理论争议。     

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 and part-list cuing in associatively structured lists

Using DRM lists (Roediger & McDermott, 1995) in two experiments, we compared the effects of retrieval practice on a subset of the items and of the presentation of those items as retrieval cues at test on recall of the lists' critical items. In Experiment 1, the critical items were part of the studied lists, thus addressing these items' veridical recall; in Experiment 2, they were not studied, thus addressing these items' false recall. Three major results emerged. First, retrieval practice and part-list cuing reduced both veridical and false recall. Second, the two manipulations induced an integration effect in veridical recall, with substantial forgetting in lists with low false recall levels and no forgetting in lists with high false recall levels. Third, retrieval practice and part-list cuing created the same effects on recall, qualitatively and quantitatively. These results suggest that the detrimental effects of retrieval practice and part-list cuing were mediated by similar mechanisms. They are consistent with the view that not only retrieval-induced forgetting, but also part-list cuing is caused by inhibitory processes.     

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.