Selective Rehearsal Research Articles

How varying cue duration influences item-method directed forgetting: A novel selective retrieval interpretation.

A series of four experiments tested the assumptions of the most prominent and longstanding account of item-method directed forgetting: the selective rehearsal account. In the item-method directed forgetting paradigm, each presented item is followed by its own instructional cue during the study phase - either to-be-forgotten (F) or to-be-remembered (R). On a subsequent test, memory is poorer for F items than for R items. To clarify the mechanism underlying memory performance, we manipulated the time available for rehearsal, examining instructional cue durations of 1 s, 5 s, and 10 s. Experiments 1a and 1b, where the order of cue durations was randomized, showed no effect of cue duration on item recognition of unrelated single words, for either R or F items. Experiment 2, using unrelated word pairs, again showed no effect of randomized cue duration, this time on associative recognition. Experiments 3 and 4 blocked cue duration and showed equivalent increases in recognition of both R and F single words and word pairs with increasing cue duration. We suggest that any post-cue rehearsal is carried out only when cue duration is predictable, and that such limited rehearsal is equally likely for F items and R items. The consistently better memory for R items than for F items across cue duration depends on selective retrieval involving (1) a rapid retrieval check engaged for R items only and (2) a rapid removal process implemented for F items only.

Simulating conversations: A Markov chain model of a central speaker's mnemonic influence over a group of communicating listeners.

Through their selective rehearsal, Central Speakers can reshape collective memory in a group of listeners, both by increasing accessibility for mentioned items (shared practice effects) and by decreasing relative accessibility for related but unmentioned items (socially shared retrieval induced forgetting, i.e., SSRIF). Subsequent networked communication in the group can further modify these mnemonic influences. Extant empirical work has tended to examine such downstream influences on a Central Speaker's mnemonic influence following a relatively limited number of interactions - often only two or three conversations. We develop a set of Markov chain simulations to model the long-term dynamics of such conversational remembering across a variety of group types, based on reported empirical data. These models indicate that some previously reported effects will stabilize in the long-term collective memory following repeated rounds of conversation. Notably, both shared practice effects and SSRIF persist into future steady states. However, other projected future states differ from those described so far in the empirical literature, specifically: the amplification of shared practice effects in communicational versus solo remembering non-conversational groups, the relatively transient impact of social (dis)identification with a Central Speaker, and the sensitivity of communicating networks to much smaller mnemonic biases introduced by the Central Speaker than groups of individual rememberers. Together, these simulations contribute insights into the long-term temporal dynamics of collective memory by addressing questions difficult to tackle using extant laboratory methods, and provide concrete suggestions for future empirical work.

A computational account of item-based directed forgetting for nonwords: Incorporating orthographic representations in MINERVA 2.

Recent research on item-method directed forgetting demonstrates that forget instructions not only decrease recognition for targets, but also decrease false recognition for foils from the same semantic categories as targets instructed to be forgotten. According to the selective rehearsal account of directed forgetting, this finding suggests that remember instructions may engage elaborative rehearsal of the category-level information of items. In contrast to this explanation, Reid and Jamieson (Canadian Journal of Experimental Psychology / Revue canadienne de psychologie expérimentale, 76(2), 75-86, 2022) proposed that the differential rates of false recognition may emerge at retrieval when foils from "remember" and "forget" categories are compared to traces in memory. Using MINERVA S, an instance model of memory based on MINERVA 2 that incorporates structured semantic representations, Reid and Jamieson successfully simulated lower false recognition for foils from "forget" categories without assuming rehearsal of category-level information. In this study, we extend the directed forgetting paradigm to categories consisting of orthographically related nonwords. Presumably participants would have difficulty rehearsing category-level information for these items because they would have no pre-experimental knowledge of these categories. To simulate the findings in MINERVA S, we imported structured orthographic representations rather than semantic representations. The model not only predicted differential rates of false recognition for foils from "remember" and "forget" categories, but also predicted higher rates of false recognition overall than what was observed for semantic categories. The empirical data closely matched these predictions. These data suggest that differential rates of false recognition due to remember and forget instructions emerge at retrieval when participants compare recognition probes to traces stored in memory.

Effects of emotion and sex difference on item-method directed forgetting

It is crucial to remember or forget others' faces in daily life. People can intentionally forget things they wish to forget, a phenomenon called directed forgetting (DF). This study examined the effects of stimuli's emotions and sex differences in participants and stimuli on DF. We used happy and angry faces as the items in a typical item-method paradigm and conducted three behavioral experiments. In Experiment 1, we recruited 60 participants to examine how emotions of stimuli and sex differences in participants and stimuli affected DF. In Experiment 2, we recruited 60 female participants and manipulated the durations of items presented during the study phase to examine whether the selective rehearsal theory was held. In Experiment 3, we recruited 50 female participants and attached recognition cues to the items presented during the test phase to examine whether the inhibitory control theory was held. We treated the sex of participants in Experiment 1, the durations of items presented during the study phase in Experiment 2 as the between-subject factors, and emotion and sex of stimuli as the with-subject factors. We conducted the mixed-design ANOVA for corrected hit rate, sensitivity, and bias based on the signal detection theory. As a result, we found that DF occurred easily for male participants, whereas not for female participants because of females' superior memorial performances and stronger sensitivities. Furthermore, we found that female participants owned the best and worst recognition rates for angry female faces and happy male faces, respectively. Our results supported the selective rehearsal theory, suggesting manipulations during the study phase had the potential to help females forget what they wished to forget. We presumed that psychologists and therapists should pay attention to the roles of sex difference in twofold, self and others, when studying people's memory and forgetting. Furthermore, the sensitivity of self and the emotion of others should be considered as well.

Different ways to forget: Electrophysiological mechanisms underlying item-method directed forgetting of angry and neutral faces.

Emotional stimuli, including faces, receive preferential processing and are consequently better remembered than neutral stimuli. Therefore, they may also be more resistant to intentional forgetting. The present study investigates the behavioral and electrophysiological consequences of instructions to selectively remember or forget angry and neutral faces. In an item-method directed forgetting experiment, angry and neutral faces were randomly presented to 25 student participants (4 males). Each face was followed by an instruction to either forget or remember it and the participants’ EEG was recorded. Later, recognition memory was unexpectedly tested for all items. Behaviorally, both hit and false alarm rates were higher for angry alike than for neutral faces. Directed forgetting occurred for neutral and angry faces as reflected in a reduction of both recognition accuracy and response bias. Event-related potentials revealed a larger late positive potential (LPP, 450 – 700 ms) for angry than for neutral faces during face presentation and, in line with selective rehearsal of remember items, a larger LPP following remember than forget cues. Forget cues generally elicited a larger frontal N2 (280 – 400 ms) than remember cues, in line with the forget instruction eliciting conflict monitoring and inhibition. Selectively following angry faces, a larger cue-evoked P2 (180 – 280 ms) was observed. Notably, forget cues following angry faces elicited a larger late frontal positivity (450 - 700 ms) potentially signaling conflict resolution. Thus, whereas both angry and neutral faces are subject to directed forgetting, on a neural level, different mechanisms underlie the effect. While directed forgetting for neutral faces may be achieved primarily by selective rehearsal, directed forgetting of angry faces involves an additional late frontal positivity, likely reflecting higher cognitive demands imposed by forgetting angry faces.

Oscillatory Correlates of Intentional Forgetting: The Role of Theta and Alpha Power in Item-Method Directed Forgetting.

Results from item-method directed forgetting suggest that individuals are able to intentionally forget processed information. Most research suggests that either selective rehearsal of to-be-remembered or inhibitory control of to-be-forgotten information is accountable for the effects of intentional forgetting. Some research, however, hypothesized that the time to process information mediates the underlying mechanism. To test this hypothesis, the current study investigated associations between oscillatory power in theta (3–7.5 Hz) and alpha frequencies (8–13 Hz) and intentional forgetting in human participants and explored whether or not these mechanisms depended on processing time. Previously, theta power was shown to be associated with the creation of episodic memory traces and alpha power with inhibition. We therefore expected to find associations between these neural signatures and behavioral effects. Consistent with our hypotheses, we revealed increased theta power for to-be-remembered and increased alpha power for to-be-forgotten information and that the effects of activity in both frequency bands were influenced by the time individuals were given for processing the memory cue. These results suggest that not one but two mechanisms, rehearsal and inhibitory control, are accountable for item-method directed forgetting, both with different temporal profiles.

Encoding mechanism in directed forgetting

<p id="p00005">Forgetting is a cognitive process that individuals tend to avoid under many circumstances, but it does not always have negative effects. Erasing some outdated information (e.g., phone numbers a long time ago) or negative information (e.g., negative emotions) from memory will not only improve one’s efficiency of memorization, but also improve one’s mental health. In psychology, this kind of forgetting is named ‘intentional forgetting’ or ‘directed forgetting’. In a typical experimental paradigm to study directed forgetting, the participants are asked to remember or forget certain items following corresponding cues in the learning stage, and then to recall or recognize these items in the subsequent testing stage. Results of previous studies have consistently shown that the score of memorization on the to-be-forgotten items is significantly lower than on the to-be-remembered items. Regarding whether directed forgetting requires cognitive effort, however, there have been controversial views including two opposing theories, namely passive decay theory and active inhibition theory. In the view of passive decay theory, directed forgetting is not necessarily a mechanism of active inhibition of memory; instead, it is a passive process that does not require cognitive effort-the to-be-forgotten items just decay passively with time for lacking an effective rehearsal as there is a selective rehearsal of the to-be-remembered items. On the contrary, active inhibition theory maintains that directed forgetting is a process of active inhibition of memory induced by the forgetting cues and hence it requires cognitive effort-this theory has not only been supported by behavioral studies but also been evidenced by the ERPs in the frontal lobe as shown in neurocognitive studies. Although the two theories attribute directed forgetting to opposing mechanisms, they are not entirely conflicting as they have consensus on the encoding mechanism of the to-be-remembered items. In addition to these two mainstream theories, there is also a viewpoint that the encoding stage of directed forgetting may involve both active inhibition and passive decay which are two processes independent in time and space, but how the two processes interact and integrate is yet to be explored. Notably, some other studies reported that the performance of forgetting on the to-be-forgotten items was even worse than on the items without any cues（these words don't need to be remembered or forgotten）, suggesting that the to-be-forgotten items have partly entered the memory, which seems to challenge both active inhibition and passive decay theories. Despite a wealth of experimental evidence, the controversy in the theory remains. To further clarify the cognitive mechanism of the encoding stage of directed forgetting, future study needs to take non-cognitive factors such as motivation and emotion into investigation, and to inspect various populations.

The influence of cue probability on item and source judgments in item method directed forgetting

ABSTRACT The current study examined how selective rehearsal strategies in item method directed forgetting are influenced by the probability of remember or forget cues from different sources. In four experiments, study words were presented by one of two sources in an item method directed forgetting paradigm. In all experiments, one source was mostly-remember (presenting twice as many remember as forget words) and the other source was mostly-forget (presenting twice as many forget as remember words). Participants completed item recognition tests (providing cue tags in Experiment 2) with source judgments. Item recognition of forget words was generally greater for the mostly-remember source than for the mostly forget source, whereas recognition of remember words was largely unaffected by source cue probability. Source judgments were consistent with heuristic guessing based on memory strength and knowledge of source cue probability. Experiment 4 analysed overt rehearsal, and showed that words from the mostly-remember source were more likely to be rehearsed prior to the memory cue. Results are discussed in terms of the influence that source cue probability knowledge has on selective rehearsal strategies, recognition decisions, and source memory attributions.

Tracking Selective Rehearsal and Active Inhibition of Memory Traces in Directed Forgetting

Selectively remembering or forgetting newly encountered information is essential for goal-directed behavior. It is still an open question, however, whether intentional forgetting is an active process based on the inhibition of unwanted memory traces or whether it occurs passively through reduced recruitment of selective rehearsal [1, 2]. Here, we show that intentional control of memory encoding relies on both, enhanced active inhibition and decreased selective rehearsal, and that these two processes can be separated in time and space. We applied representational similarity analysis (RSA [3]) and time-frequency analysis to EEG data during an item-method directed forgetting experiment [4]. We identified neural signatures of both, the intentional suppression and the voluntary upregulation of item-specific representations. Successful active forgetting was associated with a downregulation of item-specific representations in an early time window 500ms after the instruction. This process was initiated by an increase in oscillatory alpha (8-13Hz) power, a well-established signature of neural inhibition [5, 6], in occipital brain areas. During a later time window, 1500ms after the cue, intentional forgetting was associated with reduced employment of active rehearsal processes, as reflected by an attenuated upregulation of item-specific representations as compared to intentionally encoded items. Our data show that active inhibition and selective rehearsal are two separate mechanisms whose consecutive employment allows for a voluntary control of memory formation.

In support of selective rehearsal: Double-item presentation in item-method directed forgetting.

Despite the substantial evidence highlighting the role of selective rehearsal in item-method directed forgetting, recent work has suggested that forgetting may occur as a function of an active inhibitory mechanism that is more effortful than elaborative rehearsal processes. In the present work, we test this hypothesis by implementing a double-item presentation within the item-method directed forgetting paradigm. Participants studied two unrelated items at a time. Some words were followed by the same cue, and participants were instructed to remember or forget both items (pure condition). On other trials, participants were to remember one but forget the other word (mixed condition). Selective rehearsal and inhibition accounts make distinct predictions regarding memory performance in the double-item presentation. In Experiment 1, we compared recognition performance in the pure and mixed conditions, while in Experiment 2, we included a neutral baseline condition to further distinguish between the selective rehearsal and inhibition accounts. Contrary to the inhibition account but consistent with selective rehearsal, we found for both remember and forget items that recognition was greater in the mixed than in the pure condition. Recognition for forget items also did not differ from neutral items. We conclude that selective rehearsal, not inhibition, is responsible for item-method directed forgetting.

How do word frequency and memory task influence directed forgetting: An ERP study

In daily life, it is important either to remember sometimes or to intentionally forget on other occasions. The issue of forgetting following instructions (i.e. directed forgetting, DF) has been broadly studied; however, whether the frequency of contents would matter in DF remains unclear, and the understanding of its neural mechanism in both circumstances of item memory and source memory requires improvement in depth. For these purposes, the current study manipulated word frequency and memory task to investigate relevant behavioral features and neural activities of DF. Adopting event-related potential (ERP) technique, this study applied two-character Chinese words of two types of word frequency (high vs low) in the item-method DF paradigm. During encoding, we found that the increased frontal positivity, an index of active inhibition, was regulated by both word frequency and memory task, while the enhanced parietal positivity reflecting selective rehearsal didn't fluctuate across conditions. In the course of test, three ERP old/new effects were identified: the familiarity-based FN400 and the recollection-driven LPC were both modulated by word frequency and memory task, but the right frontal old/new effect was significant solely in source memory; also, these effects provided compelling evidence for the influences of word frequency and memory task on DF. Our results reinforce the differentiation between absolute familiarity and relative familiarity in memory, reveal their sensitivity to DF, and also support the dual-process interpretation. Implications are made to examine more influential factors for future research.

Does stimulus emotionality influence associative memory? Insights from directed forgetting

Prior research has demonstrated that stimulus emotionality can affect associative memory, but the patterns are varied: negative valence can either impair or improve it, while positive valence often facilitates it. In addition, it remains unclear whether the influence of stimulus emotionality on associative memory is sensitive to the manipulation of directed forgetting (DF). Thus, this experiment further explored the modulation of stimulus emotionality on associative memory in the case of DF. Besides the intact, rearranged, and new pairs usually adopted, we also included a fourth type of “old+new” pair. The results showed that the correct responses were not exactly the same among pair types; it tended to be better for both neutral and positive pairs vs negative pairs; significant DF effect was confirmed, but its susceptibility to stimulus emotionality only held true for “old+new” case. Further analyses of old proportions and response times provided further evidence for the above patterns. These findings demonstrate that the involvements of the recollection-driven process differ as the function of pair type; the modulation of stimulus emotionality on associative memory reinforces the dual representation account; reliable DF effect suggests both the pivotal roles of selective rehearsal to TBR (to-be-remembered) pairs and of inhibitory control to TBF (to-be-forgotten) pairs; furthermore, the susceptibility of the magnitude of DF effect to stimulus emotionality depends upon the involvement of recollection-driven process.

Investigating intentional forgetting using pupillometry: no evidence for the ongoing allocation of cognitive resources during forgetting

ABSTRACTThe ability to intentionally forget presented information is explained mainly by two theoretical accounts. The inhibitory control account states that forgetting is an active process, because to-be-forgotten items are inhibited. The selective rehearsal account emphasises working memory processes acting on the to-be-remembered items to aid later retrieval. Accordingly, to-be-forgotten items are dropped from working memory, because they are no longer processed. As pupil size is a reliable measure of cognitive resource allocation, we used this measure to differentiate between both theoretical accounts. Two experiments applying nonparametric statistical analyses revealed that pupils dilated most during encoding when the task required remembering. Experiment 2 revealed that participants were partly aware of the control they had over remembering and forgetting. The results of both experiments are better explained by the selective rehearsal account than by inhibitory control. Potential reasons for the occurrence of the diverging theoretical explanations of directed forgetting are discussed.

List-method directed forgetting after prolonged retention interval: Further challenges to contemporary accounts

Abstract Numerous studies on list-method directed forgetting (LMDF) have shown that people can voluntarily forget information when cued to do so. But the cognitive mechanism(s) behind this form of forgetting are still subject to debate. The present study focused on two explanations of LMDF: selective rehearsal and mental context change. Experiment 1 addressed the context-change account by comparing the persistence of LMDF with that of context-dependent forgetting. Results showed that LMDF, but not context-dependent forgetting, was lasting, which is inconsistent with the context-change account. Experiments 2 and 3 addressed the selective-rehearsal account by examining whether persistence of LMDF depends on the status of (intentionally vs. incidentally) encoded items and the type of distractor activity (demanding vs. undemanding) between study and test. Results showed that LMDF was lasting for both intentionally and incidentally studied items but was absent after an undemanding distractor task, which disagrees with the selective-rehearsal account. The present findings challenge both the context-change and the selective-rehearsal account as well as a dual-mechanisms view, which assumes a role of both types of mechanisms in LMDF.

Can self-referential information improve directed forgetting? Evidence from a multinomial processing tree model.

A large body of research has shown that self-referential processing can enhance an individual’s memory of information. However, there are many arguments about how self-referential processing affects directed forgetting (DF). In this study, two experiments were designed to investigate the DF effect and its internal psychological mechanism under explicit and implicit referential conditions using the item-method DF paradigm combined with the storage-retrieval MPT model. We compare the difference in the DF effect between self-referential and other-referential conditions and explain the reasons for the difference. Our results suggest that the item-method DF effect is the result of a selective rehearsal mechanism and a retrieval inhibition mechanism working together. Both self-reference and other-reference can cause DF in explicit referential processing or implicit referential processing, although the DF effect is stronger under the self-referential condition. Furthermore, the memory advantage effect of implicit self-referential processing is stronger than that of explicit self-referential processing.

Too hard to forget? ERPs to remember, forget, and uninformative cues in the encoding phase of item-method directed forgetting.

In item-method directed forgetting, worse memory performance occurs for to-be-forgotten (TBF) than for to-be-remembered (TBR) items. However, recently TBF items have been found to be recognized more accurately than uninformative (UI) items not associated with any specific task. Here, we compare ERPs elicited by cues signaling the remember or the forget instruction with those elicited by uninformative cues. Participants were presented with a series of complex pictures, each followed by a symbolic TBR, TBF, or UI cue. On a yes-no recognition test, accuracy was higher for TBR than for both TBF and UI items. However, TBF items were recognized more accurately than UI items. ERPs elicited by the TBR cue were larger than ERPs elicited by both TBF and UI cues at the frontal P2, the late frontal negativity, and the late parietal positivity complex. This is consistent with more attention capture, selective rehearsal, and long-term memory encoding of TBR. In contrast, both TBF and UI cues induced a larger frontal N2 than TBR cues. Critically, TBF elicited a larger late right-frontal positivity than both UI and TBR cues and a larger late parietal positivity than UI cues. Moreover, the late right-frontal positivity was correlated with better recognition performance. It may therefore reflect processing orientation rather than inhibition per se. Results suggest that, when compared to UI cues, both TBR and TBF cues are processed actively. Distinct processing is seen at right frontal and centroparietal positive ERPs that may mediate better subsequent recognition of TBF than of UI items.

Item-method directed forgetting: Effects at retrieval?

In an item-method directed forgetting paradigm, words are presented one at a time, each followed by an instruction to Remember or Forget; a directed forgetting effect is measured as better subsequent memory for Remember words than Forget words. The dominant view is that the directed forgetting effect arises during encoding due to selective rehearsal of Remember over Forget items. In three experiments we attempted to falsify a strong view that directed forgetting effects in recognition are due only to encoding mechanisms when an item method is used. Across 3 experiments we tested for retrieval-based processes by colour-coding the recognition test items. Black colour provided no information; green colour cued a potential Remember item; and, red colour cued a potential Forget item. Recognition cues were mixed within-blocks in Experiment 1 and between-blocks in Experiments 2 and 3; Experiment 3 added explicit feedback on the accuracy of the recognition decision. Although overall recognition improved with cuing when explicit test performance feedback was added in Experiment 3, in no case was the magnitude of the directed forgetting effect influenced by recognition cueing. Our results argue against a role for retrieval-based strategies that limit recognition of Forget items at test and posit a role for encoding intentions only.

Can We Retrieve the Information Which Was Intentionally Forgotten? Electrophysiological Correlates of Strategic Retrieval in Directed Forgetting.

Retrieval inhibition hypothesis of directed forgetting effects assumed TBF (to-be-forgotten) items were not retrieved intentionally, while selective rehearsal hypothesis assumed the memory representation of retrieved TBF (to-be-forgotten) items was weaker than TBR (to-be-remembered) items. Previous studies indicated that directed forgetting effects of item-cueing method resulted from selective rehearsal at encoding, but the mechanism of retrieval inhibition that affected directed forgetting of TBF (to-be-forgotten) items was not clear. Strategic retrieval is a control process allowing the selective retrieval of target information, which includes retrieval orientation and strategic recollection. Retrieval orientation via the comparison of tasks refers to the specific form of processing resulted by retrieval efforts. Strategic recollection is the type of strategies to recollect studied items for the retrieval success of targets. Using a “directed forgetting” paradigm combined with a memory exclusion task, our investigation of strategic retrieval in directed forgetting assisted to explore how retrieval inhibition played a role on directed forgetting effects. When TBF items were targeted, retrieval orientation showed more positive ERPs to new items, indicating that TBF items demanded more retrieval efforts. The results of strategic recollection indicated that: (a) when TBR items were retrieval targets, late parietal old/new effects were only evoked by TBR items but not TBF items, indicating the retrieval inhibition of TBF items; (b) when TBF items were retrieval targets, the late parietal old/new effect were evoked by both TBR items and TBF items, indicating that strategic retrieval could overcome retrieval inhibition of TBF items. These findings suggested the modulation of strategic retrieval on retrieval inhibition of directed forgetting, supporting that directed forgetting effects were not only caused by selective rehearsal, but also retrieval inhibition.

Selective rehearsal is affected by the emotionality of the encoding context in item-method directed forgetting: An event-related potential study

Emotional items are often remembered more clearly than neutral items. However, whether stimuli embedded in an emotional context are more resistant to directed forgetting than those presented in a neutral context remains unclear. This question was tested by recording event-related potentials (ERPs) in an item-method directed forgetting paradigm involving neutral words that were embedded in neutral or negative contexts. During the study phase, participants were asked to associate a neutral word with a negative or neutral picture. A remember (R) or forget (F) cue was then designated to indicate whether the word was a to-be-remembered (TBR) or to-be-forgotten (TBF) word. In the test phase, participants were asked to identify all previously presented old words regardless of the R/F cues. The behavioral results indicated a significant interaction between the valence of the encoding contexts and the R/F cues. The hit rate was lower for the TBR words encoded in negative contexts relative to those encoded in neutral contexts. No such valence effect was observed in the hit rates of the TBF words. For the ERP data, the R cues elicited a P3b-like effect that has been linked to the selective rehearsal of the TBR items. This effect was more sustained in the negative encoding context than in the neutral context. The F cues elicited a frontal positivity that has been linked to the active inhibition of the TBF words; however, this positivity was not modulated by the valence of the encoding context. The sustained P3b-like effect for the R cues in the negative encoding context might reflect a compensative encoding for the TBR words caused by the attention-capturing negative contexts. Therefore, we argue that the emotional context affected the selective elaboration of the TBR words; however, we also argue that there was no supportive evidence of an emotional effect on the forgetting of TBF items.

Control of information in working memory: Encoding and removal of distractors in the complex-span paradigm

The article reports four experiments with complex-span tasks in which encoding of memory items alternates with processing of distractors. The experiments test two assumptions of a computational model of complex span, SOB-CS: (1) distractor processing impairs memory because distractors are encoded into working memory, thereby interfering with memoranda; and (2) free time following distractors is used to remove them from working memory by unbinding their representations from list context. Experiment 1 shows that distractors are erroneously chosen for recall more often than not-presented stimuli, demonstrating that distractors are encoded into memory. Distractor intrusions declined with longer free time, as predicted by distractor removal. Experiment 2 shows these effects even when distractors precede the memory list, ruling out an account based on selective rehearsal of memoranda during free time. Experiments 3 and 4 test the notion that distractors decay over time. Both experiments show that, contrary to the notion of distractor decay, the chance of a distractor intruding at test does not decline with increasing time since encoding of that distractor. Experiment 4 provides additional evidence against the prediction from distractor decay that distractor intrusions decline over an unfilled retention interval. Taken together, the results support SOB-CS and rule out alternative explanations. Data and simulation code are available on Open Science Framework: osf.io/3ewh7.