Part-list cuing as instructed retrieval inhibition

Effects of Selective Retrieval Practice on Older Adults: Lesser Benefits, Greater Losses

Retrieval practice enhances memory for practiced information, but at the price of impairing memory for unpracticed information, a phenomenon known as retrieval-induced forgetting (RIF). Evidence has shown that, for young adults, RIF can be eliminated after a long interval and when textual information is used as a memorandum. The current study aims to determine whether RIF is more durable and difficult to overcome for older adults due to their cognitive deficits. Both young and older participants completed a learning session on Day 1, during which they studied word pairs (Experiment 1) or scientific prose (Experiment 2). Then, they engaged in selective retrieval practice on Days 3, 5, or 7. Finally, they undertook a final test on Day 8. Experiment 1 showed no RIF for young but a robust RIF for older participants. Experiment 2 observed retrieval-induced facilitation for young but RIF for older participants. Although both young and older participants were encouraged to use an integration technique to facilitate learning during Experiment 2, the levels of integration only predicted the magnitudes of retrieval-induced facilitation for young but not for older participants. This study shows that older adults should be careful of carrying out selective retrieval because this may produce a more durable impairment in their memory for unpracticed information.

A context-based model of collaborative inhibition during memory search

Contrary to common intuition, a group of people recalling information together remembers less than the same number of individuals recalling alone (i.e., the collaborative inhibition effect). To understand this effect in a free recall task, we build a computational model of collaborative recall in groups, extended from the Context Maintenance and Retrieval (CMR) model, which captures how individuals recall information alone. We propose that in collaborative recall, one not only uses their previous recall as an internal retrieval cue, but one also listens to someone else's recall and uses it as an external retrieval cue. Attending to this cue updates the listener's context to be more similar to the context of someone else's recall. Over an existing dataset of individual and collaborative recall in small and large groups, we show that our model successfully captures the difference in memory performance between individual recall and collaborative recall across different group sizes from 2 to 16, as well as additional recall patterns such as recency effects and semantic clustering effects. Our model further shows that collaborating individuals reach similar areas in the context space, whereby their contexts converge more than the contexts of individuals recalling alone. This convergence constrains their ability to search memories effectively and is negatively associated with recall performance. We discuss the contributions of our modeling results in relation to previous accounts of the collaborative inhibition effect.

Modeling collaborative memory with SAM

While humans often encode and retrieve memories in groups, the bulk of our knowledge of human memory comes from paradigms with individuals in isolation. The primary phenomenon of interest within the relatively new field of collaborative memory is collaborative inhibition: the tendency for collaborative groups to underperform in free recall tasks compared with noncollaborative groups of the same size. This effect has been found in a variety of materials and group compositions. However, most research in this field is led by verbal conceptual theories without guidance from formal computational models. We present a framework to scale the Search of Associative Memory model (SAM) to collaborative free recall paradigms with multiple models working together. Multiple SAM models recalling together naturally produce collaborative inhibition when the group members use recalls by the group as cues to retrieve from memory, strongly supporting the "retrieval disruption" hypothesis. This work shows that SAM can act as a unified theory to explain both individual and collaborative memory effects and offers a framework for future predictions of scaling to increased group sizes, shared knowledge, and factors facilitating the spread of false memories in groups.

The saving enhanced memory effect can be observed when only a subset of items are saved

Saving one list of words, such as on a computer or by writing them down, can improve a person's ability to learn and remember a second list of words that are not saved. This phenomenon, known as the saving enhanced memory effect, is typically observed by comparing the recall of nonsaved items when other items are saved versus when they are not saved. In past research, the effect has been shown to occur when participants save an entire list before learning a new list. In the current research, we examined whether the effect can be observed when participants save a subset of items within a single list. The results of two experiments confirmed that partial saving can lead to a saving enhanced memory effect, with the effect observed regardless of whether participants saved items by clicking a button on the computer or writing them out by hand. The effect was observed on an item-specific cued-recall test (Experiment 1) as well as a free recall test that did not control the order of output (Experiment 2). However, the effect size did vary as a function of how participants attempted to recall the items on the final test. Specifically, participants who initiated their output by recalling nonsaved items exhibited a significantly larger saving enhanced memory effect than those who initiated their output by reproducing saved items. Together, these findings expand our understanding of the saving enhanced memory effect and shine new light on the impacts of cognitive offloading on human memory.

Collaborative encoding with a new categorization task: a contribution to collaborative memory research

Collaborative memory research has focused primarily on the effects of collaboration at recall with collaboration during encoding receiving less attention. In the present study, collaboration was investigated both at encoding and at retrieval to determine its effects and possible interactions. The aim was to clarify whether the collaborative inhibition effect depended on whether the encoding was with the same or with a different partner. A total of 320 participants (160 Italian and 160 Spanish undergraduate students) were administered a modified version of the collaborative memory paradigm with a new categorization task of verbal affective stimuli at encoding. Specifically, they were asked to classify 90 printed words into 6 categories, so as to have 15 words in each category and then did two recall tasks. Participants were assigned to one of five possible conditions according to encoding (collaborative, individual) and recall (collaborative with the same partner, with another partner, and individual). Results show a collaborative encoding deficit and the classic collaborative inhibition effect independently of whether the encoding was collaborative or individual and even in a collaborative recall group that showed a degree of recall output organization comparable to that of the individual recall group. These results are not wholly consistent with a retrieval disruption explanation and are discussed according to divided attention during collaborative recall and how it may contribute to the collaborative inhibition effect.

Part-set cuing effects in spatial memory: the role of interitem associations

Part-set cuing facilitation and impairment effects are rarely found in spatial memory, which is a challenge to the theories of part-set cuing effects based on lexical stimulus. This study aims to investigate whether there part-set cuing facilitation and impairment effects are present in spatial memory by constructing two types of memory scenes with high and low degrees of interitem associations, achieved by manipulating the presentation of miniatures. This study examined the effects of different part-set cues on free recall, recognition, and reconstruction tasks. The results of two experiments revealed that matrix cues impaired the performance of three recall tasks in memory scenes with a high degree of interitem associations, and scene cues facilitated the reconstruction performance (Experiment 1). Conversely, in memory scenes with a low degree of interitem associations, the impairment effect of matrix cues was not observed in the three recall tasks, but scene cues still facilitated the reconstruction performance (Experiment 2). These findings supported the retrieval strategy disruption hypothesis, the two-mechanism and the multi-mechanism accounts, demonstrating the significance of interitem associations in spatial memory. Furthermore, the results provided direct evidence for the importance of the encoding-retrieval strategy matching principle in spatial memory tasks.

The effect of part-list cuing on associative recognition

The modulation of part-list cuing on item memory has been well-documented, whereas its impact on associative memory remains largely unknown. The present study explored the effect of part-list cuing on associative recognition and, more specifically, whether this forgetting effect caused by part-list cuing is more sensitive to recollection or familiarity in recognition memory. Experiments 1a and 1b combined the intact/rearranged/new judgement task of associative recognition with the classical part-list cuing paradigm, and the result showed that part-list cuing impaired the recognition accuracy of "intact" and "rearranged" face-scene pairs. Moreover, the discriminability score of relational recognition and item recognition was significantly decreased in the part-list cuing condition compared to the no-part-list cuing condition. Experiments 2a and 2b further used the Remember/Know/Guess task to explore which recognition processes (recollection vs. familiarity) were sensitive to the presentation of part-list cuing. The results showed that part-list cuing reduced the familiarity of relational recognition and the recollection and familiarity of item recognition. These findings suggest that part-list cuing was harmful to the recognition of relationships (familiarity) and items (recollection and familiarity) in associative memory.

Improving Memory Search Through Model-Based Cue Selection

We often use cues from our environment when we get stuck searching our memories, but prior research has failed to show benefits of cuing with other, randomly selected list items during memory search. What accounts for this discrepancy? We proposed that cues' content critically determines their effectiveness and sought to select the right cues by building a computational model of how cues affect memory search. Participants (N = 195 young adults from the United States) recalled significantly more items when receiving our model's best (vs. worst) cue. Our model provides an account of why some cues better aid recall: Effective cues activate contexts most similar to the remaining items' contexts, facilitating recall in an unsearched area of memory. We discuss our contributions in relation to prominent theories about the effect of external cues.

Protecting against mental impasses: Evidence of selective retrieval mitigating the impact of fixation in creative problem solving

A common issue in creative problem solving is the unintended fixation on strongly associated, yet inappropriate solutions. In two experiments, we investigated whether lowering their accessibility by means of selective retrieval can positively affect subsequent problem-solving performance in a Compound Remote Associate test. Misleading associates were strengthened by letting participants memorize them alongside with neutral words. Half of the participants then selectively retrieved the neutral words in a cued recall test, temporarily weakening the activation level of induced fixation. In both experiments, this resulted in less impairment of subsequent performance for fixated CRA problems in early problem-solving stages (0-30 s). Additional results further revealed that participants who had engaged in prior selective retrieval perceived an increased feeling of having had immediate access to target solutions. These findings correspond to the assumption of inhibitory processes being a critical factor in both retrieval-induced forgetting and overcoming fixation in creative problem solving or preventing it from occurring in the first place. Also, they provide important insight into how strongly problem solving success is influenced by fixation.

Deceitful Hints: a Meta-Analytic Review of the Part-List Cuing Impairment in Recall

A large body of research in the study of memory has accumulated to date on the part-list cuing impairment in recall. This phenomenon refers to the lower recall of studied information in the presence of some studied words provided as retrieval cues compared to when no cues are provided. We review the current literature on the part-list cuing impairment in recall and report a meta-analysis utilizing the procedural and statistical information obtained from 109 samples (N = 5,605). In each experiment, participants studied a list of words and subsequently performed a recall task either in the presence or absence of part-list cues. The meta-analysis shows that the part-list cuing impairment is a robust, medium-sized impairment (Cohen, 1988). This recall impairment was not significantly sensitive to the number of study items provided, the relationship among study items, the number of part-list cues provided, the amount of time provided for recall, or certain other factors of interest. Our analyses also demonstrate that longer retention periods between study and retrieval mitigate the part-list cuing impairment in recall. We discuss the implications of meta-analysis results for elements of experimental design, the findings of past literature, as well as the underlying theoretical mechanisms proposed to account for this impairment in recall and the applied consequences of this recall impairment.

Selective restudy can reset recall of forgotten information

Recall of studied material is typically impaired as time between study and test increases. Selective restudy can interrupt such time-dependent forgetting by enhancing recall not only of the restudied but also of the not restudied material. In two experiments, we examined whether this interruption of time-dependent forgetting reflects a transient or more lasting effect on recall performance. We analyzed time-dependent forgetting of studied items right after study and after time-lagged selective restudy. Restudy boosted recall of the not restudied items up to the levels observed directly after study and created a restart of time-dependent forgetting from this enhanced recall level. Critically, the forgetting after restudy was indistinguishable from the forgetting after study, suggesting that restudy induced a reset of recall for the not restudied items. The results are consistent with the idea that restudy reactivates the temporal context during study, thus facilitating recall of the not restudied items. In particular, the findings suggest that such context updating reflects a lasting effect that entails a restart of the original time-dependent forgetting. Results are discussed with respect to recent, similar findings on effects of time-lagged selective retrieval.

Retrieval practice transfer effects for multielement event triplets

Retrieval practice (RP) leads to improved retention relative to re-exposure and is considered a robust phenomenon when the final test conditions are identical to RP conditions. However, the extent to which RP 'transfers' to related material is less clear. Here, we tested for RP transfer effects under conditions known to induce integration of associated material at encoding, which may make transfer more likely. Participants learned multielement triplets (locations, animals and objects) and one pairwise association from each triplet was tested through RP, re-exposed, or not re-exposed (control). Two days later participants completed a final test of all pairwise associations. We found no evidence for an RP effect compared to re-exposure, but both tested/re-exposed pairs were better remembered than the not re-exposed control condition. We also found that transfer occurred from both tested to untested and re-exposed to not re-exposed pairs. Our results highlight that RP and re-exposure can boost retention for directly tested/re-exposed event pairs and associated but untested/not re-exposed event pairs, suggesting re-exposure of integrated information can be of pedagogical value. The results also question the boundary conditions for an increase in retention for RP relative to re-exposure, highlighting the need for a better theoretical understanding of RP effects.

The part-list cuing effect in working memory: The influence of task presentation mode

The modulation of part-list cues on long-term memory has been well-documented, whereas its impact on working memory remains largely unknown. The current study recruited a working memory part-list cuing paradigm to investigate how re-exposing part-list items affected item representation in working memory, and more specifically, whether the cuing effect was modulated by the task presentation mode. Our results showed that when the part-list re-exposure and no-part-list re-exposure trials were presented in separate blocks, using the re-exposed items as retrieval cues (part-list cue condition) significantly impaired recognition speed, accuracy and elevated judgement criteria (Experiment 1a), whereas merely relearning the re-exposed items (part-list relearning condition) has no such effect (Experiment 1b). When the part-list cue trials are randomly interleaved with the no-part-list cue trials, recognition accuracy was significantly lower in the part-list cue condition, whereas the recognition speed and judgement criteria were not significantly different under the two conditions (Experiment 2). These results indicate that re-exposing subsets of previously memorized items as retrieval cues can reduce the strength of other representations in working memory. Moreover, the effect of part-list cues in working memory is affected by task presentation mode. The mechanisms of part-list cuing within working memory were discussed.

Self-paced part-list cuing

Ironically, the presentation of a subset of studied material as retrieval cues at test often impairs recall of the remaining (target) material-an effect known as part-list cuing impairment. Part-list cues are typically provided at the beginning of the recall period, a time when nearly all individuals would be able to recall at least some studied items on their own. Across two experiments, we examined the effects of part-list cuing when student participants could decide on their own when the cues were presented during the recall period. Results showed that participants activated the cues relatively late in the recall period, when recall was already close to asymptote. Critically, such delayed cuing no longer impaired recall performance. The detrimental effect of part-list cuing, as it has been demonstrated numerous times in the memory literature, thus seems to depend on presentating the cue items (too) early in the recall period.

Oscillatory Correlates of Selective Restudy

Prior behavioral work has shown that selective restudy of some studied items leaves recall of the other studied items unaffected when lag between study and restudy is short, but improves recall of the other items when lag is prolonged. The beneficial effect has been attributed to context retrieval, assuming that selective restudy reactivates the context at study and thus provides a retrieval cue for the other items (Bäuml, 2019). Here the results of two experiments are reported, in each of which subjects studied a list of items and then, after a short 2-min or a prolonged 10-min lag, restudied some of the list items. Participants' electroencephalography (EEG) was recorded during both the study and restudy phases. In Experiment 2, but not in Experiment 1, subjects engaged in a mental context reinstatement task immediately before the restudy phase started, trying to mentally reinstate the study context. Results of Experiment 1 revealed a theta/alpha power increase from study to restudy after short lag and an alpha/beta power decrease after long lag. Engagement in the mental context reinstatement task in Experiment 2 eliminated the decrease in alpha/beta power. The results are consistent with the view that the observed alpha/beta decrease reflects context retrieval, which became obsolete when there was preceding mental context reinstatement.

Induced Forgetting Is the Result of True Forgetting, Not Shifts in Decision-making Thresholds

Induced forgetting occurs when accessing an item in memory appears to harm memory representations of categorically related items. However, it is possible that the actual memory representations are unharmed. Instead, people may just change how they make decisions. Specifically, signal detection theory suggests this apparent forgetting may be due to participants shifting their decision criterion. Here, we used behavioral and electrophysiological measures to determine whether induced forgetting is truly due to changes in how items are represented or simply due to a shifting criterion. Participants' behavior and brain activity showed that induced forgetting was due to changes in the strength of the underlying representations, weighing against a criterion shift explanation of induced forgetting.

Part-List Cues Hinder Familiarity but Not Recollection in Item Recognition: Behavioral and Event-Related Potential Evidence

Participants' memory performance is normally poorer when a subset of previously learned items is provided as retrieval cues than none of the retrieval cues is provided. This phenomenon is called the part-list cuing effect, which has been discovered in numerous behavioral studies. However, there is currently no relevant behavioral or event-related potential (ERP) research to investigate whether the forgetting effect caused by part-list cues is more sensitive to recollection or to familiarity. By combining the part-list cuing paradigm with the Remember/Know procedure, we investigated this issue in the present ERP study. Behavioral data showed part-list cuing induced detrimental effect in two aspects: significantly lowered familiarity of the target items and decreased memory discrimination score (P_r score) for "Know" but not for "Remember" items in the part-list cue condition than in the no-part-list cue condition. ERP data revealed that the FN400 old/new effects, which are associated with familiarity, were absent when providing part-list cues, whereas the late positive complex (LPC) old/new effects, which are associated with recollection, were observed comparably in both part-list cue and no-part-list cue conditions. Converging behavioral and ERP results suggested that part-list cues hindered familiarity-based retrieval but not recollection-based retrieval of item recognition. Theoretical implications of the findings for the part-list cuing effect are discussed.

Part-list cuing with prose material: When cuing is detrimental and when it is not

Numerous studies have shown that the presentation of some studied items as retrieval cues at test can impair recall of the remaining items. This effect, often referred to as part-list cuing (PLC) impairment, has mostly been demonstrated with simple word lists and short retention intervals between study and test. Across 4 experiments, this study examined the effects of PLC with educationally relevant prose passages for retention intervals of up to one week. Results showed that the effects of PLC with prose material depend critically on retention interval and test format. In the absence of any further retrieval cues, Experiments 1-3 found detrimental effects of PLC after short delay but neutral effects of PLC after delays of 2 days or 1 week. In the presence of gapped sentences ("fill-in-the-blank") serving as (additional) retrieval cues at test, Experiment 4 found a neutral effect of PLC after short delay but a beneficial effect after a delay of 2 days. With prose material, detrimental effects of PLC may thus be restricted to short retention interval and neutral or even beneficial effects may arise after prolonged retention interval. The findings suggest that both detrimental mechanisms - like blocking and inhibition - and beneficial mechanisms - like context reactivation - contribute to the effects of PLC with prose material.

Age differences in the persistence of part-list cuing impairment: The role of retrieval inhibition and strategy disruption

Providing a subset of previously studied information as a retrieval cue can impair memory for the remaining information. Previous work with adults has shown that such part-list cuing impairment (PLCI) can be transient or lasting, depending on study condition. Here, we investigated the persistence of PLCI in children. Three age groups (7- and 8-year-olds, 9- and 10-year-olds, and 12- to 14-year-olds) learned a list of items, either through a single study trial (1-study condition) or through two study-test cycles (2-study-test condition). Subsequently, two recall tests were administered, with part-list cues being provided in the first (critical) test but not in the second (final) test. Of primary interest was whether the detrimental effect of part-list cuing induced in the critical test would persist to the uncued final test. In 12- to 14-year-olds, we found an adult-like pattern of results, with lasting impairment in the 1-study condition but transient impairment in the 2-study-test condition. In contrast, in the two younger age groups, we found PLCI to be lasting in both study conditions, suggesting age differences in the persistence of PLCI. The results are discussed in light of a recently proposed two-mechanism account of PLCI that attributes lasting impairment to retrieval inhibition and transient impairment to strategy disruption. Following this account, the results suggest that whereas 12- to 14-year-olds' PLCI was caused by (lasting) retrieval inhibition in the 1-study condition and by (transient) strategy disruption in the 2-study-test condition, 7- and 8-year-olds' and 9- and 10-year-olds' PLCI was caused by (lasting) retrieval inhibition in both study conditions.

The Many Faces of Part-List Cuing-Evidence for the Interplay Between Detrimental and Beneficial Mechanisms

If participants study a list of items and, at test, receive a random selection of the studied items as retrieval cues, then such cuing often impairs recall of the remaining items. This effect, referred to as part-list cuing impairment, is a well-established finding in memory research that, over the years, has been attributed to quite different cognitive mechanisms. Here, we provide a review of more recent developments in research on part-list cuing. These developments (i) suggest a new view on part-list cuing impairment and a critical role of encoding for the effect, (ii) identify conditions in which part-list cuing impairment can turn into part-list cuing facilitation, and (iii) relate research on part-list cuing to a phenomenon from social memory, known as collaborative inhibition. The recent developments also include a new multi-mechanisms account, which attributes the effects of cuing to the interplay between detrimental mechanisms—like blocking, inhibition, or strategy disruption—and beneficial mechanisms—like context reactivation. The account provides a useful theoretical framework to describe both older and newer findings. It may guide future work on part-list cuing and may also motivate new research on collaborative inhibition.

Towards augmented human memory: Retrieval-induced forgetting and retrieval practice in an interactive, end-of-day review

The authors report 6 experiments that examined the contention that an end-of-day review could lead to augmentation in human memory. In Experiment 1, participants in the study phase were presented with a campus tour of different to-be-remembered objects in different university locations. Each to-be-remembered object was presented with an associated specific comment. Participants were then shown the location name and photographs of half of the objects from half of the locations, and they were asked to try to name the object and recall the associated comment specific to each item. Following a filled delay, participants were presented with the name of each campus location and were asked to free recall the to-be-remembered objects. Relative to the recall from the unpracticed location categories, participants recalled the names of significantly more objects that they practiced (retrieval practice) and significantly fewer unpracticed objects from the practiced locations (retrieval-induced forgetting, RIF). These findings were replicated in Experiment 2 using a campus scavenger hunt in which participants selected their own stimuli from experimenter’s categories. Following an examination of factors that maximized the effects of RIF and retrieval practice in the laboratory (Experiment 3), the authors applied these findings to the campus scavenger hunt task to create different retrieval practice schedules to maximize and minimize recall of items based on experimenter-selected (Experiment 4) and participant-selected items using both category-cued free recall (Experiment 5) and item-specific cues (Experiment 6). Their findings support the claim that an interactive, end-of-day review could lead to augmentation in human memory.

Younger and older adults' collaborative recall of shared and unshared emotional pictures

Although a group of people working together recalls more items than any one individual, they recall fewer unique items than the same number of people working apart whose responses are combined. This is known as collaborative inhibition, and it is a robust effect that occurs for both younger and older adults. However, almost all previous studies documenting collaborative inhibition have used stimuli that were neutral in emotional valence, low in arousal, and studied by all group members. In the current experiments, we tested the impact of picture-stimuli valence, picture-stimuli arousal, and information distribution in modulating the magnitude of collaborative inhibition. We included both younger and older adults because there are age differences in how people remember emotional pictures that could modulate any effects of emotion on collaborative inhibition. Results revealed that when information was shared (i.e., studied by all group members), there were robust collaborative inhibition effects for both neutral and emotional stimuli for both younger and older adults. However, when information was unshared (i.e., studied by only a single group member), these effects were attenuated. Together, these results provide mixed support for the retrieval strategy disruption account of collaborative inhibition. Supporting the retrieval strategy disruption account, unshared study information was less susceptible to collaborative inhibition than shared study information. Contradicting the retrieval strategy disruption account, emotional valence and arousal did not modulate the magnitude of collaborative inhibition despite the fact that participants clustered the emotional, but not neutral, information together in memory.

Part-list cuing effects in children: A developmental dissociation between the detrimental and beneficial effect

Providing a subset of previously studied items as a retrieval cue can both impair and improve recall of the remaining items. Here, we investigated the development of these two opposing effects of such part-list cuing in children. Using listwise directed forgetting to manipulate study context access, three child age groups (7-8, 9-11, and 13-14years) and young adults studied a list of items and, after study, were asked to either forget or continue remembering the list. After presentation of a second list, participants were tested on predefined target items from the original list in either the presence or absence of the list's remaining (nontarget) items serving as retrieval cues. Results revealed that part-list cuing impaired recall of to-be-remembered target items regardless of age. In contrast, part-list cuing improved recall of to-be-forgotten target items in the adult and the oldest child groups but not in the two younger child groups. This finding suggests a developmental dissociation between the two opposing effects of part-list cuing, indicating that the beneficial effect develops later than the detrimental effect. In particular, following the view that the beneficial effect of part-list cuing arises from reactivation of the study context, the results suggest that elementary school children have difficulty in capitalizing on context reactivation.

Comparing the testing effect under blocked and mixed practice: The mnemonic benefits of retrieval practice are not affected by practice format

The act of retrieving information modifies memory in critical ways. In particular, testing-effect studies have demonstrated that retrieval practice (compared to restudy or to no testing) benefits long-term retention and protects from retroactive interference. Although such testing effects have previously been demonstrated in both between- and within-subjects manipulations of retrieval practice, it is less clear whether one or the other testing format is most beneficial on a final test. In two paired-associate learning experiments conducted under typical testing-effect conditions, we manipulated restudy and test trials using either blocked or mixed practice conditions while equating other factors. Retrieval-practice and restudy trials were presented either separately in different blocks (blocked practice) or randomly intermixed (mixed practice). In Experiment 1, recall was assessed after short and long delay intervals; in Experiment 2, the final memory test occurred after a short delay, but with or without an interfering activity before the final test. In both experiments, typical testing effects emerged, and critically, they were found to be unaffected by practice format. These results support the conclusion that testing effects are robust and emerge to equal extents in both blocked and mixed designs. The generality of testing effects further encourages the application of retrieval practice as a memory enhancer in a variety of contexts, including education.

Erroneous and veridical recall are not two sides of the same coin: Evidence from semantic distraction in free recall

Two experiments examined the extent to which erroneous recall blocks veridical recall using, as a vehicle for study, the disruptive impact of distractors that are semantically similar to a list of words presented for free recall. Instructing participants to avoid erroneous recall of to-be-ignored spoken distractors attenuated their recall but this did not influence the disruptive effect of those distractors on veridical recall (Experiment 1). Using an externalized output-editing procedure-whereby participants recalled all items that came to mind and identified those that were erroneous-the usual between-sequences semantic similarity effect on erroneous and veridical recall was replicated but the relationship between the rate of erroneous and veridical recall was weak (Experiment 2). The results suggest that forgetting is not due to veridical recall being blocked by similar events.

Spatial part-set cuing facilitation

Cole, Reysen, and Kelley [2013. Part-set cuing facilitation for spatial information. Journal of Experimental Psychology: Learning, Memory, & Cognition, 39, 1615-1620] reported robust part-set cuing facilitation for spatial information using snap circuits (a colour-coded electronics kit designed for children to create rudimentary circuit boards). In contrast, Drinkwater, Dagnall, and Parker [2006. Effects of part-set cuing on experienced and novice chess players' reconstruction of a typical chess midgame position. Perceptual and Motor Skills, 102(3), 645-653] and Watkins, Schwartz, and Lane [1984. Does part-set cuing test for memory organization? Evidence from reconstructions of chess positions. Canadian Journal of Psychology/Revue Canadienne de Psychologie, 38(3), 498-503] showed no influence of part-set cuing for spatial information when using chess boards. One key difference between the two procedures was that the snap circuit stimuli were explicitly connected to one another, whereas chess pieces were not. Two experiments examined the effects of connection type (connected vs. unconnected) and cue type (cued vs. uncued) on memory for spatial information. Using chess boards (Experiment 1) and snap circuits (Experiment 2), part-set cuing facilitation only occurred when the stimuli were explicitly connected; there was no influence of cuing with unconnected stimuli. These results are potentially consistent with the retrieval strategy disruption hypothesis, as well as the two- and three-mechanism accounts of part-set cuing.

Initial retrieval shields against retrieval-induced forgetting

Testing, as a form of retrieval, can enhance learning but it can also induce forgetting of related memories, a phenomenon known as retrieval-induced forgetting (RIF). In four experiments we explored whether selective retrieval and selective restudy of target memories induce forgetting of related memories with or without initial retrieval of the entire learning set. In Experiment 1, subjects studied category-exemplar associations, some of which were then either restudied or retrieved. RIF occurred on a delayed final test only when memories were retrieved and not when they were restudied. In Experiment 2, following the study phase of category-exemplar associations, subjects attempted to recall all category-exemplar associations, then they selectively retrieved or restudied some of the exemplars. We found that, despite the huge impact on practiced items, selective retrieval/restudy caused no decrease in final recall of related items. In Experiment 3, we replicated the main result of Experiment 2 by manipulating initial retrieval as a within-subject variable. In Experiment 4 we replicated the main results of the previous experiments with non-practiced (Nrp) baseline items. These findings suggest that initial retrieval of the learning set shields against the forgetting effect of later selective retrieval. Together, our results support the context shift theory of RIF.

Interference from mere thinking: mental rehearsal temporarily disrupts recall of motor memory

Interference between successively learned tasks is widely investigated to study motor memory. However, how simultaneously learned motor memories interact with each other has been rarely studied despite its prevalence in daily life. Assuming that motor memory shares common neural mechanisms with declarative memory system, we made unintuitive predictions that mental rehearsal, as opposed to further practice, of one motor memory will temporarily impair the recall of another simultaneously learned memory. Subjects simultaneously learned two sensorimotor tasks, i.e., visuomotor rotation and gain. They retrieved one memory by either practice or mental rehearsal and then had their memory evaluated. We found that mental rehearsal, instead of execution, impaired the recall of unretrieved memory. This impairment was content-independent, i.e., retrieving either gain or rotation impaired the other memory. Hence, conscious recollection of one motor memory interferes with the recall of another memory. This is analogous to retrieval-induced forgetting in declarative memory, suggesting a common neural process across memory systems. Our findings indicate that motor imagery is sufficient to induce interference between motor memories. Mental rehearsal, currently widely regarded as beneficial for motor performance, negatively affects memory recall when it is exercised for a subset of memorized items.

Why two heads apart are better than two heads together: multiple mechanisms underlie the collaborative inhibition effect in memory

Although a group of people working together remembers more than any one individual, they recall less than their predicted potential. This finding is known as collaborative inhibition and is generally thought to arise due to retrieval disruption. However, there is growing evidence that is inconsistent with the retrieval disruption account, suggesting that additional mechanisms also contribute to collaborative inhibition. In the current studies, we examined 2 alternate mechanisms: retrieval inhibition and retrieval blocking. To identify the contributions of retrieval disruption, retrieval inhibition, and retrieval blocking, we tested how collaborative recall of entirely unshared information influences subsequent individual recall and individual recognition memory. If collaborative inhibition is due solely to retrieval disruption, then there should be a release from the negative effects of collaboration on subsequent individual recall and recognition tests. If it is due to retrieval inhibition, then the negative effects of collaboration should persist on both individual recall and recognition memory tests. Finally, if it is due to retrieval blocking, then the impairment should persist on subsequent individual free recall, but not recognition, tests. Novel to the current study, results suggest that retrieval inhibition plays a role in the collaborative inhibition effect. The negative effects of collaboration persisted on a subsequent, always-individual, free-recall test (Experiment 1) and also on a subsequent, always-individual, recognition test (Experiment 2). However, consistent with the retrieval disruption account, this deficit was attenuated (Experiment 1). Together, these results suggest that, in addition to retrieval disruption, multiple mechanisms play a role in collaborative inhibition. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

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.

Memory retrieval as a self-propagating process

Retrieval of a subset of studied items and the presentation of those items as retrieval cues typically impair retrieval of the other items. Previous research on this self-limiting property of memory retrieval has relied heavily on short retention intervals and similar context between encoding and test. Here, we examined retrieval dynamics also after a prolonged retention interval with different spatial and social context between encoding and test, conditions that mimic people's remembering in many situations of daily life. For both unrelated word lists and more integrated prose material, we found retrieval and cuing to impair recall of other studied items after a short retention interval, but to improve recall in the prolonged retention interval condition. The results demonstrate that retrieval dynamics depend critically on situation, indicating that quite often in daily life, retrieval may be a self-propagating, rather than a self-limiting process.

High working memory capacity predicts less retrieval induced forgetting

BACKGROUND

Working Memory Capacity (WMC) is thought to be related to executive control and focused memory search abilities. These two hypotheses make contrasting predictions regarding the effects of retrieval on forgetting. Executive control during memory retrieval is believed to lead to retrieval induced forgetting (RIFO) because inhibition of competing memory traces during retrieval renders them temporarily less accessible. According to this suggestion, superior executive control should increase RIFO. Alternatively, superior focused search abilities could diminish RIFO, because delimiting the search set reduces the amount of competition between traces and thus the need for inhibition. Some evidence suggests that high WMC is related to more RIFO, which is inconsistent with the focused search hypothesis.

METHODOLOGY/PRINCIPAL FINDINGS

Using the RIFO paradigm, we created distinct and overlapping categories to manipulate the amount of competition between them. This overlap increased competition between some categories while exclusive use of weak exemplars ensured negligible effects of output interference and integration. Low WMC individuals exhibited RIFO within and between overlapping categories, indicating the effect of resolving competition during retrieval. High WMC individuals only exhibited between-category RIFO, suggesting they experienced reduced competition resolution demands. Low WMC Individuals exhibited the strongest RIFO and no retrieval benefits when interference resolution demands were high.

CONCLUSIONS/SIGNIFICANCE

Our findings qualify the inhibitory explanation for RIFO by incorporating the focused search hypothesis for materials that are likely to pose extraordinary challenges at retrieval. The results highlight the importance of considering individual differences in retrieval-induced effects and qualify existing models of these effects.

Suppression in retrieval practice, part-set cueing, and negative priming memory: the hydrogen model

A number of phenomena in memory have been explained using appeals to active suppression processes, including retrieval practice, part-set cueing, and the negative priming that is observed with associative interference. However, more formal attempts to capture such processes have been absent. This paper outlines the hydrogen model of memory retrieval, which aims to be a simple model with the modest goal of trying to explore what influence suppression would have on memory retrieval. This model contains a single activation component and a single suppression component in which suppression comes into play only after retrieval interference has been detected. This model was created to explore the plausibility and viability of ideas about the operation of suppression during memory retrieval. For hydrogen, the degree of suppression recruited is proportional to the amount of interference experienced. Overall, the pattern of human data was captured by the suppression model.

Retrieval-induced forgetting without competition: testing the retrieval specificity assumption of the inhibition theory

According to the inhibition theory of forgetting (Anderson, Journal of Memory and Language 49:415–445, 2003; Anderson, Bjork, & Bjork, Psychonomic Bulletin & Review 7:522-530, 2000), retrieval practice on a subset of target items leads to forgetting for the other, nontarget items, due to the fact that these other items interfere during the retrieval process and have to be inhibited in order to resolve the interference. In this account, retrieval-induced forgetting occurs only when competition takes place between target and nontarget items during target item practice, since only in such a case is inhibition of the nontarget items necessary. Strengthening of the target item without active retrieval should not lead to such an impairment. In two experiments, we investigated this assumption by using noncompetitive retrieval during the practice phase. We strengthened the cue–target item association during practice by recall of the category name instead of the target item, and thus eliminated competition between the different item types (as in Anderson et al., Psychonomic Bulletin & Review 7:522-530 2000). In contrast to the expectations of the inhibition theory, retrieval-induced forgetting occurred even without competition, and thus the present study does not support the retrieval specificity assumption.

Collaborative memory and part-set cueing impairments: the role of executive depletion in modulating retrieval disruption

When people are exposed to a subset of previously studied list items they recall fewer of the remaining items compared to a condition where none of the studied items is provided during recall. This occurs both when the subset of items is provided by the experimenter (i.e., the part-set cueing deficit in individual recall) and when they are provided during the course of a collaborative discussion (i.e., the collaborative inhibition effect in group recall). Previous research has identified retrieval disruption as a common mechanism underlying both effects; however, less is known about the factors that may make individuals susceptible to such retrieval disruption. In the current studies we tested one candidate factor: executive control. Using an executive depletion paradigm we directly manipulated an individual's level of executive control during retrieval. Results revealed no direct role of executive depletion in modulating retrieval disruption. In contrast, executive control abilities were indirectly related to retrieval disruption through their influence at encoding. Together these results suggest that executive control des not directly affect retrieval disruption at the retrieval stage, and that the role of this putative mechanism may be limited to the encoding stage.

Theta oscillations reflect the dynamics of interference in episodic memory retrieval

Selectively retrieving episodic information from a cue often induces interference from related episodes. To promote successful retrieval of the target episode, such interference is resolved by inhibition, causing retrieval-induced forgetting of the related but irrelevant information. Passively studying the episodic information again (reexposure) does not show this effect. This study examined the hypothesis that brain oscillations in the theta band (5-9 Hz) reflect the dynamics of interference in selective memory retrieval, analyzing EEG data from 24 healthy human subjects (21 women, 3 men). High versus low levels of interference were investigated by comparing the effects of selective retrieval with the effects of reexposure of material, with the former, but not the latter, inducing interference. Moreover, we analyzed repeated cycles of selective retrieval and reexposure, assuming that interference is reduced by inhibition across retrieval cycles, but not across reexposure cycles. We found greater theta band activity in selective retrieval than in reexposure, and a reduction in theta amplitude from the first to the second cycle of retrieval predicting the amount of retrieval-induced forgetting; the sources of theta amplitude reduction across retrieval cycles were located in the anterior cingulate cortex. No difference in theta activity was found across repeated cycles of reexposure. The results suggest that higher levels of interference in episodic memory are indexed by more theta band activity, and that successful interference resolution via inhibition causes a reduction in theta amplitude. Thus, theta band activity can serve as a neural marker of the dynamics of interference in selective episodic retrieval.

Part-set cuing in option generation

Memory research on the part-set cuing effect has shown that providing some of the to-be-remembered items as cues is not always beneficial and, in some cases, may even hurt retrieval. However, part-set cuing has been sparsely investigated in option generation tasks. Thus, limited empirical evidence for the existence of the effect in option generation is available, and no convincing explanation has been provided yet. In order to fill these gaps, we carried out four experiments. In Experiment 1A, we observed a significant decrease in option generation performance when potential options were presented as cues. Experiment 1B showed that the effect can also be obtained in older adults. Experiments 2A and 2B provided evidence compatible with an inhibition-based explanation of the observed effects.

Retrieval from Episodic Memory: Neural Mechanisms of Interference Resolution

Selectively retrieving a target memory among related memories requires some degree of inhibitory control over interfering and competing memories, a process assumed to be supported by inhibitory mechanisms. Evidence from behavioral studies suggests that such inhibitory control can lead to subsequent forgetting of the interfering information, a finding called retrieval-induced forgetting [Anderson, M. C., Bjork, R. A., & Bjork, E. L. Remembering can cause forgetting: Retrieval dynamics in long-term memory. Journal of Experimental Psychology: Learning, Memory & Cognition, 20, 1063–1087, 1994]. In the present functional magnetic resonance imaging study, we investigated the neural processes underlying retrieval-induced forgetting and, in particular, examined the extent to which these processes are retrieval (i.e., selection) specific. Participants actively retrieved a subset of previously studied material (selection condition), or were re-exposed to the same material for relearning (nonselection condition). Replicating prior behavioral work, selective retrieval caused significant forgetting of the nonretrieved items on a delayed recall test, relative to the re-exposure condition. Selective retrieval was associated with increased BOLD responses in the posterior temporal and parietal association cortices, in the bilateral hippocampus, and in the dorsolateral prefrontal cortex. Medial and lateral prefrontal areas showed a strong negative linear relationship between selection-related neural activity and subsequent forgetting of competitors. These findings suggest reduced demands on inhibitory control processes when interference is successfully resolved during early selective retrieval from episodic memory.

Part-list cuing and the dynamics of false recall

False recall of an unpresented critical word after studying its semantic associates can be reduced substantially if the strongest and earliest-studied associates are presented as part-list cues during testing (Kimball & Bjork, 2002). To disentangle episodic and semantic contributions to this decline in false recall, we factorially manipulated the cues' serial position and their strength of association to the critical word. Presenting cues comprising words that had been studied early in a list produced a greater reduction in false recall than did presenting words studied late in the list, independent of the cues' associative strength, but only when recall of the cues themselves was prohibited. When recall of the cues was permitted, neither early-studied nor late-studied cues decreased false recall reliably, relative to uncued lists. The findings suggest that critical words and early-studied words share a similar fate during recall, owing to selective episodic strengthening of their associations during study.

Part-list cuing with and without item-specific probes: the role of encoding

Part-list cuing--the detrimental effect of the presentation of a subset of studied items on recall of the remaining noncue items--was examined in three different study conditions and in the presence and absence of the noncues' initial letters serving as item-specific probes. With a single study trial, part-list cuing was observed both with and without item-specific probes. By contrast, when participants received two study-test cycles or interrelated list items to a common story, part-list cues were found to be detrimental only in the absence of item-specific probes, but not in their presence. These results indicate that the role of item-specific probes in part-list cuing depends on encoding. The findings are consistent with a recent two-mechanism account of part-list cuing (Bäuml & Aslan, 2006), according to which two different mechanisms mediate the effect in different encoding situations.