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.     

The effects of initial testing on false recall and false recognition in the social contagion of memory paradigm

In three experiments, participants studied photographs of common household scenes. Following study, participants completed a category-cued recall test without feedback (Exps. 1 and 3), a category-cued recall test with feedback (Exp. 2), or a filler task (no-test condition). Participants then viewed recall tests from fictitious previous participants that contained erroneous items presented either one or four times, and then completed final recall and source recognition tests. The participants in all conditions reported incorrect items during final testing (a social contagion effect), and across experiments, initial testing had no impact on false recall of erroneous items. However, on the final source-monitoring recognition test, initial testing had a protective effect against false source recognition: Participants who were initially tested with and without feedback on category-cued initial tests attributed fewer incorrect items to the original event on the final source-monitoring recognition test than did participants who were not initially tested. These data demonstrate that initial testing may protect individuals’ memories from erroneous suggestions.     

No source memory for unrecognized items when implicit feedback is avoided

In a recent empirical study, Starns, Hicks, Brown, and Martin (Memory & Cognition, 36, 1–8 2008) collected source judgments for old items that participants had claimed to be new and found residual source discriminability depending on the old-new response bias. The authors interpreted their finding as evidence in favor of the bivariate signal-detection model, but against the two-high-threshold model of item/source memory. According to the latter, new responses only follow from the state of old-new uncertainty for which no source discrimination is possible, and the probability of entering this state is independent of the old-new response bias. However, when missed old items were presented for source discrimination, the participants could infer that the items had been previously studied. To test whether this implicit feedback led to second retrieval attempts and thus to source memory for presumably unrecognized items, we replicated Starns et al.’s (Memory & Cognition, 36, 1–8 2008) finding and compared their procedure to a procedure without such feedback. Our results challenge the conclusion to abandon discrete processing in source memory; source memory for unrecognized items is probably an artifact of the procedure, by which implicit feedback prompts participants to reconsider their recognition judgment when asked to rate the source of old items in the absence of item memory.     

Retrieval practice enhances the accessibility but not the quality of memory

Numerous studies have demonstrated that retrieval from long-term memory (LTM) can enhance subsequent memory performance, a phenomenon labeled the retrieval practice effect. However, the almost exclusive reliance on categorical stimuli in this literature leaves open a basic question about the nature of this improvement in memory performance. It has not yet been determined whether retrieval practice improves the probability of successful memory retrieval or the quality of the retrieved representation. To answer this question, we conducted three experiments using a mixture modeling approach (Zhang & Luck, 2008) that provides a measure of both the probability of recall and the quality of the recalled memories. Subjects attempted to memorize the color of 400 unique shapes. After every 10 images were presented, subjects either recalled the last 10 colors (the retrieval practice condition) by clicking on a color wheel with each shape as a retrieval cue or they participated in a control condition that involved no further presentations (Experiment 1) or restudy of the 10 shape/color associations (Experiments 2 and 3). Performance in a subsequent delayed recall test revealed a robust retrieval practice effect. Subjects recalled a significantly higher proportion of items that they had previously retrieved relative to items that were untested or that they had restudied. Interestingly, retrieval practice did not elicit any improvement in the precision of the retrieved memories. The same empirical pattern also was observed following delays of greater than 24 hours. Thus, retrieval practice increases the probability of successful memory retrieval but does not improve memory quality.     

A dual memory theory of the testing effect

A new theoretical framework for the testing effect—the finding that retrieval practice is usually more effective for learning than are other strategies—is proposed, the empirically supported tenet of which is that separate memories form as a consequence of study and test events. A simplest case quantitative model is derived from that framework for the case of cued recall. With no free parameters, that model predicts both proportion correct in the test condition and the magnitude of the testing effect across 10 experiments conducted in our laboratory, experiments that varied with respect to material type, retention interval, and performance in the restudy condition. The model also provides the first quantitative accounts of (a) the testing effect as a function of performance in the restudy condition, (b) the upper bound magnitude of the testing effect, (c) the effect of correct answer feedback, (d) the testing effect as a function of retention interval for the cases of feedback and no feedback, and (e) the effect of prior learning method on subsequent learning through testing. Candidate accounts of several other core phenomena in the literature, including test-potentiated learning, recognition versus cued recall training effects, cued versus free recall final test effects, and other select transfer effects, are also proposed. Future prospects and relations to other theories are discussed.     

Feeling of knowing and restudy choices

Feeling-of-knowing judgments (FOK-Js) reflect people’s confidence that they would be able to recognize a currently unrecallable item. Although much research has been devoted to the factors determining the magnitude and accuracy of FOK-Js, much less work has addressed the issue of whether FOK-Js are related to any form of metacognitive control over memory processes. In the present study, we tested the hypothesis that FOK-Js are related to participants’ choices of which unrecallable items should be restudied. In three experiments, we showed that participants tend to choose for restudy items with high FOK-Js, both when they are explicitly asked to choose for restudy items that can be mastered in the restudy session (Exps. 1a and 2) and when such specific instructions are omitted (Exp. 1b). The study further demonstrated that increasing FOK-Js via priming cues affects restudy choices, even though it does not affect recall directly. Finally, Experiment 2 showed the strategy of restudying unrecalled items with high FOK-Js to be adaptive, because the efficacy of restudy is greater for these items than for items with low FOK-Js. Altogether, the present findings underscore an important role of FOK-Js for the metacognitive control of study operations.     

Temporal encoding strategies result in boosts to final free recall performance comparable to spatial ones

The method of loci is a highly effective mnemonic that recruits existing salient memory for spatial locations and uses the information as a scaffold for remembering a list of items (Yates, 1966). One possible account for the effectiveness of the spatial method of loci comes from the perspective that it utilizes evolutionarily preserved mechanisms for spatial navigation within the hippocampus (Maguire et al. in Proceedings of the National Academy of Sciences, 97(8), 4398–4403, 2000; O’Keefe & Nadel, 1978; Rodriguez et al. in Brain Research Bulletin, 57(3), 499–503, 2002). Recently, though, neurons representing temporal information have also been described within the hippocampus (Eichenbaum in Nature Reviews Neuroscience, 15(11), 732–744, 2014; Itskov, Curto, Pastalkova, & Buzsáki in The Journal of Neuroscience, 31(8), 2828–2834, 2011; MacDonald, Lepage, Eden, & Eichenbaum in Neuron, 71(4), 737–749, 2011; Mankin et al. in Proceedings of the National Academy of Sciences, 109(47), 19462–19467, 2012; Meck, Church, & Matell in Behavioral Neuroscience, 127(5), 642, 2013), challenging the primacy of spatial-based functions to hippocampal processing. Given the presence of both spatial and temporal coding mechanisms within the hippocampus, we predicted that primarily temporal encoding strategies might also enhance memory. In two different experiments, we asked participants to learn lists of unrelated nouns using the (spatial) method of loci (i.e., the layout of their home as the organizing feature) or using two novel temporal methods (i.e., autobiographical memories or using the steps to making a sandwich). Participants’ final free recall performance showed comparable boosts to the method of loci for both temporal encoding strategies, with all three scaffolding approaches demonstrating performance well above uninstructed free recall. Our findings suggest that primarily temporal representations can be used effectively to boost memory performance, comparable to spatial methods, with some caveats related to the relative ease with which participants appear to master the spatial versus temporal methods.     

Metacognitive control in self-regulated learning: Conditions affecting the choice of restudying versus retrieval practice

In two experiments, learners studied word pairs one or two times and took a final cued recall test. They studied each pair upon its initial presentation and decided whether they would restudy it later, take a practice test on it later (retrieval practice), or forego all further practice with the pair. Whether learners preferred restudying or testing depended upon conditions. Regardless of whether practice tests were followed by feedback, they chose to take practice tests relatively more often when items were easy and the lag or spacing interval between the first and second occurrence was short, whereas they chose to restudy relatively more when items were hard and the lag was long. That is, they preferred testing under conditions in which successful retrieval on the practice test was likely. In Experiment 2, we varied the number of points each item was worth if recalled on the final test. A high point value led to a marked increase in both the preference for testing when the lag was short and the preference for restudying when the lag was long. Results support the hypothesis that learners appreciate at some level that retrieval practice can be a more effective learning strategy than restudying. However, they appear to believe that successful retrieval is necessary to reap the benefits of retrieval practice. As a consequence, their tendency to choose testing is influenced by conditions (item difficulty and spacing interval) that affect the likelihood of successful practice-test retrieval.     

Recall is not necessary for verbal sequence learning

The question of whether overt recall of to-be-remembered material accelerates learning is important in a wide range of real-world learning settings. In the case of verbal sequence learning, previous research has proposed that recall either is necessary for verbal sequence learning (Cohen & Johansson Journal of Verbal Learning and Verbal Behavior, 6, 139–143, 1967; Cunningham, Healy, & Williams Journal of Experimental Psychology: Learning, Memory, and Cognition, 10, 575–597, 1984), or at least contributes significantly to it (Glass, Krejci, & Goldman Journal of Memory and Language, 28, 189–199, 1989; Oberauer & Meyer Memory, 17, 774–781, 2009). In contrast, here we show that the amount of previous spoken recall does not predict learning and is not necessary for it. We suggest that previous research may have underestimated participants’ learning by using suboptimal performance measures, or by using manual or written recall. However, we show that the amount of spoken recall predicted how much interference from other to-be-remembered sequences would be observed. In fact, spoken recall mediated most of the error learning observed in the task. Our data support the view that the learning of overlapping auditory–verbal sequences is driven by learning the phonological representations and not the articulatory motor responses. However, spoken recall seems to reinforce already learned representations, whether they are correct or incorrect, thus contributing to a participant identifying a specific stimulus as either “learned” or “new” during the presentation phase.     

The role of overt language production in the Hebb repetition effect

The Hebb repetition effect (Hebb, 1961) occurs when recall performance improves for a list that is repeated during a serial-recall task. This effect is considered a good experimental analogue to language learning. Our objective was to evaluate the role of overt language production in language learning by manipulating recall direction during a Hebb repetition paradigm. In each trial, seven nonsense syllables were presented auditorily. Participants had to orally recall the items either in the presentation order or in reverse order. One sequence was repeated every third trial. In Experiment 1, we compared learning from a group that had recalled the items in their presentation order to learning from a group that had recalled the items in the reverse order. The two groups yielded similar learning rates. In Experiment 2, recall direction was varied between trials. The learning rate was not affected when recall direction varied between trials, suggesting a limited role of overt language production in language learning.     

Overt language production plays a key role in the Hebb repetition effect

When asked to recall verbatim a short list of items, performance is very limited. However, if the list of items is repeated across trials, recall performance improves. This phenomenon, known as the Hebb repetition effect (Hebb, 1961; Brain Mechanisms and Learning: A Symposium, pp. 37–51), is considered a laboratory analogue of language learning. In effect, learning a new word implies the maintenance of a series of smaller units, such as phonemes or syllables, in the correct order for a short amount of time before producing them. The sequence of smaller units is typically presented more than once. In the present study, we investigated the role of overt language production in language learning by manipulating recall direction. If the learning of a repeated list of items relies on overt language production processes, changing list production order by manipulating recall direction should impact the learning of the list. In Experiment 1, one list was repeated every third trial, and recall direction of the repeated list changed on the ninth repetition. In Experiment 1a, the repeated list changed from a forward to a backward order recall, where participants had to recall the items in reverse presentation order. In Experiment 1b, the repeated list changed from a backward to a forward order recall. Results showed a cost in recall performance for the repeated list when recall direction switched from forward to backward recall, whereas it was unaffected by the change from backward to forward recall. In Experiment 2, we increased the number of trials before introducing the change from a backward to a forward order recall. Results showed a decrement in recall performance for the repeated list following the change in recall direction, suggesting that language production processes play a role in the Hebb repetition effect.     

Phonological recoding under articulatory suppression

We report data from an experiment in which participants performed immediate serial recall of visually presented words with or without articulatory suppression, while also performing homophone or rhyme detection. The separation between homophonous or rhyming pairs in the list was varied. According to the working memory model (Baddeley, 1986; Baddeley & Hitch, 1974), suppression should prevent articulatory recoding. Nevertheless, rhyme and homophone detection was well above chance. However, with suppression, participants showed a greater tendency to false-alarm to orthographically related foils (e.g., GIVE–FIVE). This pattern is similar to that observed in short-term memory patients.     

Adaptive memory: Is the animacy effect on memory due to emotional arousal?

Animate entities are often better remembered than inanimate ones. The proximal mechanisms underlying this animacy effect on recall are unclear. In two experiments, we tested whether the animacy effect is due to emotional arousal. Experiment 1 revealed that translations of the animate words used in the pioneering study of Nairne et al. (Psychological science, 24, 2099–2105, 2013) were perceived as being more arousing than translations of the inanimate words, suggesting that animacy might have been confounded with arousal in previous studies. In Experiment 2, new word lists were created in which the animate and inanimate words were matched on arousal (amongst several other dimensions), and participants were required to reproduce the animate and inanimate words in a free recall task. There was a tendency towards better memory for arousing items, but robust animacy effects were obtained even though animate and inanimate words were matched on arousal. Thus, while arousal may contribute to the animacy effect when it is not carefully controlled for, it cannot explain the memory advantage of animate items.     

Hypermnesia and the Role of Delay between Study and Test

Hypermnesia is increased recall across repeated tests in the absence of any further study opportunities. Although over the years many factors have been identified that influence hypermnesia, to date not much is known about the role of delay between study and test for the effect. This study addressed the issue in four experiments. Employing both words and pictures as study material, we compared hypermnesia after shorter delay (3 min or 11.5 min) and longer delay (24 h or 1 week) between study and test. Recall occurred over three successive tests, using both free recall (Experiments 1, 2, and 4) and forced recall testing (Experiment 3). In forced recall tests, subjects are instructed to recall as many items as possible, but if unable to remember all studied items, to fill in the remaining spaces with their best guesses. With free recall testing, hypermnesia increased with delay and the effect was driven mainly by reduced item losses between tests. These results suggest a link between hypermnesia and the testing effect, which shows that demanding retrieval practice, as it happens after longer delay, can improve recall by reducing the forgetting of the practiced items. In contrast, with forced recall testing, hypermnesia decreased with delay and was even absent after longer delay. The findings indicate that recall format can influence hypermnesia and different mechanisms may mediate the effects of repeated testing in the two recall conditions.     

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

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

Norms of valence and arousal for 14,031 Spanish words

Most current models of research on emotion recognize valence (how pleasant a stimulus is) and arousal (the level of activation or intensity that a stimulus elicits) as important components in the classification of affective experiences (Barrett, 1998; Kuppens, Tuerlinckx, Russell, & Barrett, 2012). Here we present a set of norms for valence and arousal for a very large set of Spanish words, including items from a variety of frequencies, semantic categories, and parts of speech, including a subset of conjugated verbs. In this regard, we found that there were significant but very small differences between the ratings for conjugations of the same verb, validating the practice of applying the ratings for infinitives to all derived forms of the verb. Our norms show a high degree of reliability and are strongly correlated with those of Redondo, Fraga, Padrón, and Comesaña’s (2007) Spanish version of the influential Affective Norms for English Words (Bradley & Lang, 1999), as well as those from Warriner, Kuperman, and Brysbaert (2013), the largest available set of emotional norms for English words. Additionally, we included measures of word prevalence—that is, the percentage of participants that knew a particular word—for each variable (Keuleers, Stevens, Mandera, & Brysbaert, 2015). Our large set of norms in Spanish not only will facilitate the creation of stimuli and the analysis of texts in that language, but also will be useful for cross-language comparisons and research on emotional aspects of bilingualism. The norms can be downloaded and available as a supplementary materials to this article.     

Retrieval-induced forgetting: Evidence for a recall-specific mechanism

Previous work has shown that recalling information from long-term memory can impair the long-term retention of related representations—a phenomenon known as retrieval-induced forgetting (Anderson, Bjork, & Bjork, 1994). We report an experiment in which the question of whether retrieval is necessary to induce this form of impairment was examined. All the subjects studied six members from each of eight taxonomic categories (e.g.,fruit orange). In the competitive practice condition, the subjects practiced recalling three of the six members, using category-stem cues (e.g.,fruit or____). In the noncompetitive practice condition, the subjects were reexposed to these same members for the same number of repetitions but were asked to recall the category name by using the exemplar and a stem as cues (e.g.,fr____orange). Despite significant and comparable facilitation of practiced items in both conditions, only the competitive practice subjects were impaired in their ability to recall the nonpracticed members on a delayed cued-recall test. These findings argue that retrieval-induced forgetting is not caused by increased competition arising from the strengthening of practiced items, but by inhibitory processes specific to the situation of recall.     

Separating the effect of reward from corrective feedback during learning in patients with Parkinson’s disease

Parkinson’s disease (PD) is associated with procedural learning deficits. Nonetheless, studies have demonstrated that reward-related learning is comparable between patients with PD and controls (Bódi et al., Brain, 132(9), 2385–2395, 2009; Frank, Seeberger, & O’Reilly, Science, 306(5703), 1940–1943, 2004; Palminteri et al., Proceedings of the National Academy of Sciences of the United States of America, 106(45), 19179–19184, 2009). However, because these studies do not separate the effect of reward from the effect of practice, it is difficult to determine whether the effect of reward on learning is distinct from the effect of corrective feedback on learning. Thus, it is unknown whether these group differences in learning are due to reward processing or learning in general. Here, we compared the performance of medicated PD patients to demographically matched healthy controls (HCs) on a task where the effect of reward can be examined separately from the effect of practice. We found that patients with PD showed significantly less reward-related learning improvements compared to HCs. In addition, stronger learning of rewarded associations over unrewarded associations was significantly correlated with smaller skin-conductance responses for HCs but not PD patients. These results demonstrate that when separating the effect of reward from the effect of corrective feedback, PD patients do not benefit from reward.     

Validation of a Brief Version of the Difficulties in Emotion Regulation Scale (DERS-18) in Five Samples

The field of affective clinical science has expanded dramatically over the past several decades (Rottenberg and Gross 2003; Tracy et al. 2014). An important part of this research is understanding emotion regulation and dysregulation, in particular, how individuals differ in their ability to identify, accept, and manage their emotional experiences. One of the most common and widely cited measures of emotion dysregulation is the Difficulties with Emotion Regulation Scale (DERS; Gratz and Roemer 2004), which has been extensively used to facilitate understanding of how emotion dysregulation is associated with psychiatric symptoms, other emotion-related constructs, and treatment progress. While this scale has contributed greatly to our understanding of emotion regulation problems, its length makes its inclusion in brief study protocols difficult, limiting its utility and increasing participant burden. In order to address this issue, we developed a short form version of the DERS (DERS-18) composed of the strongest items from each of the measure’s six subscales from the original DERS publication (Gratz and Roemer 2004), and then validated this measure in five datasets that vary in age and sample type. Our results demonstrate that an 18-item short-form of the DERS exhibits a similar structure as the original 36-item DERS, demonstrates excellent reliability and validity, and performs similarly to the original DERS despite comprising half the items. The DERS-18 has the potential to improve and expand emotion regulation assessment while reducing demands on research participants.     

Distilling Common History and Practice Elements to Inform Dissemination: Hanf-Model BPT Programs as an Example

There is a shift in evidence-based practice toward an understanding of the treatment elements that characterize empirically supported interventions in general and the core components of specific approaches in particular. The evidence base for behavioral parent training (BPT) and the standard of care for early-onset disruptive behavior disorders (oppositional defiant disorder and conduct disorder), which frequently co-occur with attention deficit hyperactivity disorder, are well established, yet an ahistorical, program-specific lens tells little regarding how leaders, University of Oregon Medical School, shaped the common practice elements of contemporary evidence-based BPT. Accordingly, this review summarizes the formative work of Hanf, as well as the core elements, evolution, and extensions of her work, represented in Community Parent Education (COPE; (Cunningham et al. in J Child Psychol Psychiatry 36:1141–1159, 1995; Cunningham et al. in COPE, the community parent education program: large group community-based workshops for parents of 3- to 18-year-olds, COPE Works, Hamilton, 2009), Defiant Children (DC; (Barkley in Defiant children: a clinician’s manual for assessment and parent training, Guilford Press, New York, 1987; Barkley in Defiant children: a clinician’s manual for assessment and parent training, Guilford Press, New York, 2013), Helping the Noncompliant Child (HNC; Forehand and McMahon in Helping the noncompliant child: a clinician’s guide to parent training, Guilford Press, New York, 1981; McMahon and Forehand in Helping the noncompliant child: family-based treatment for oppositional behavior, 2nd ed., Guilford Press, New York, 2003), Parent–child interaction therapy (PCIT; Eyberg and Robinson in J Clin Child Adolesc Psychol 11:130–137, 1982. doi:10.1080/15374418209533076; Eyberg in Child Fam Behav Ther 10:33–46, 1988; Eyberg and Funderburk in Parent–child interaction therapy protocol, PCIT International, Gainesville, 2011), and the Incredible Years (IY; (Webster-Stratton in Behav Ther 12:634–642, 1981. doi:10.1016/S0005-7894(81)80135-9; Webster-Stratton in J Pediatr Psychol 7:279–294, 1982. doi:10.1093/jpepsy/7.3.279; Webster-Stratton in The incredible years: parents and children series. Leader’s guide: preschool version of BASIC (ages 3–6 years, The Incredible Years, Seattle, 2008). Our goal is not to provide an exhaustive review of the evidence base for the Hanf-Model programs, rather our intention is to provide a template of sorts from which agencies and clinicians can make informed choices about how and why they are using one program versus another, as well as how to make inform flexible use one program or combination of practice elements across programs, to best meet the needs of child clients and their families. Clinical implications and directions for future work are discussed.