Long-term Memory Research Articles

The hippocampus and implicit memory.

The traditional memory-systems view is that explicit (conscious) long-term memory is associated with the hippocampus and implicit (nonconscious) memory is associated with non-hippocampal brain regions. This special issue of Cognitive Neuroscience focuses on whether the hippocampus is associated with implicit memory. An empirical fMRI paper by Miller, Kennard, Gowland, Antoniades, and Rosenthal (this issue) evaluated recognition memory performance of autobiographical amnesia patients with bilateral damage to hippocampal sub-region CA3 and found they had greater than chance recognition memory performance for spatial sequence learning, spatial item learning-same location, and non-spatial item learning, but chance performance for non-spatial sequence learning and spatial item learning-different location. These results are at odds with the view that the hippocampus is generally involved in sequence learning and complex event recognition. A discussion paper by Steinkrauss and Slotnick (this issue) considered whether fMRI studies have provided evidence that the hippocampus is associated with implicit memory. It was argued that all previous studies have been confounded by explicit memory, attentional states, stimuli, or novelty. This discussion paper is followed by commentaries from Hannula (this issue), Henke and Ruch (this issue), Rosenthal (this issue), Spaak (this issue), Thakral et al. (this issue), and Züst (this issue). The articles in this special issue illustrate that the association between the hippocampus and implicit memory is under active investigation and debate. It is hoped that the evidence and discourse in this issue will provide directions for future research.

Enhanced Osteosarcoma Immunotherapy via CaCO3 Nanoparticles: Remodelling Tumour Acidic and Immune Microenvironment for Photodynamic Therapy.

Osteosarcoma (OS) is a "cold" tumour enriched in noninflammatory M2 phenotype tumour-associated macrophages (TAMs), which limits the efficacy of immunotherapy. The acidic tumour microenvironment (TME), generated by factors such as excess hydrogen (H+) ions and high lactate levels, activates immunosuppressive cells (e.g., M2 phenotype TAMs), further promoting a suppressive tumour immune microenvironment (TIME). Therefore, a multitarget synergistic combination strategy that neutralizes the acidic TME and reprograms TAMs can be beneficial for OS therapy. Here, a calcium carbonate (CaCO3)/polydopamine (PDA)-based nanosystem (A-NPs@(SHK+Ce6)) was developed for the targeted codelivery of the photosensitizer Ce6 and shikonin (SHK) to OS tumours via the bone-targeting ability of alendronate sodium (ALN). CaCO3 nanoparticles were used to neutralize H+ ions and alleviate the suppressive TIME, and the loaded SHK not only synergized with photodynamic therapy (PDT) by promoting reactive oxygen species (ROS) generation and enhancing immunogenic cell death (ICD) but also inhibited lactate production, further reversing the acidic TME and repolarizing TAMs to consequently lead to enhanced PDT-induced tumour suppression and comprehensive beneficial effects on antitumour immune responses, including the promotion of CD8+ T-cell infiltration and regulatory T-cell (Treg) suppression. Importantly, A-NPs@(SHK+Ce6), in combination with programmed cell death protein 1 (PD-1) checkpoint blockade, showed a remarkable ability to eliminate distant tumours and promote long-term immune memory function to protect against rechallenged tumours. This work presents a novel multiple-component combination strategy that coregulates the acidic TME and TAM polarization to reprogram the TIME. This article is protected by copyright. All rights reserved.

Recognizing the opponent: The consolidation of long-term social memory in zebrafish males.

Recognizing and remembering another individual in a social context could be beneficial for individual fitness. Especially in agonistic encounters, remembering an opponent and the previous fight could allow for avoiding new conflicts. Considering this, we hypothesized that this type of social interaction forms a long-term recognition memory lasting several days. It has been shown that a second encounter 24 h later between the same pair of zebrafish males is resolved with lower levels of aggression. Here, we evaluated if this behavioral change could last for longer intervals and a putative mechanism associated with memory storage: the recruitment of NMDA receptors. We found that if a pair of zebrafish males fight and fight again 48 or 72 h later, they resolve the second encounter with lower levels of aggression. However, if opponents were exposed to MK-801 (NMDA receptor antagonist) immediately after the first encounter, they solved the second one with the same levels of aggression: that is, no reduction in aggressive behaviors was observed. These amnesic effect suggest the formation of a long-term social memory related to recognizing a particular opponent and/or the outcome and features of a previous fight.

Proactive interference of visual working memory chunks implicates long-term memory.

Visual working memory (VWM) is a limited cognitive resource that can be functionally expanded through chunking (Miller, 1956). For example, participants can hold an increasing number of colours in mind as they learn to chunk reliably paired combinations (Bradyet al.,2009). We investigated whether this benefit is mediated through the in situ compression of VWM representations (Brady et al.,2009) or the offloading of chunks to long-term memory (LTM; Huang & Awh, 2018; Ngiam et al., 2019) by asking if a vulnerability of LTM - proactive interference - influences VWM performance. We adapted previous designs using deterministic (Experiment 1, N = 60) and probabilistic pairings (Experiments 2 and 3, N = 64 and 80, respectively), to include colour pairings that swapped in sequence along with pairings that were consistent in sequence. Generally, participants reported colours from consistent pairs more accurately than from swapping pairs, which we designed to drive interference in LTM (Experiments 1 and 2). The error profiles also pointed to proactive interference between swapping pairs in all three experiments. Moreover, participants who had explicit awareness of frequent colour pairings had higher VWM accuracy, and their errors reflected more proactive interference than their unaware counterparts (Experiment 3). This pattern of long-term proactive interference in a VWM task lends support for accounts of VWM chunking that propose LTM offloading.

The arousal level of consciousness required for working memory performance: An anaesthesia study.

Regarding the stage of arousal level required for working memory to function properly, limited studies have been conducted on changes in working memory performance when the arousal level of consciousness decreases. This study aimed to experimentally clarify the stages of consciousness necessary for optimal working memory function. In this experiment, the sedation levels were changed step-by-step using anaesthesia, and the performance accuracy during the execution of working memory was assessed using a dual-task paradigm. Participants were required to categorize and remember words in a specific target category. Categorization performance was measured across four different sedative phases: before anaesthesia (baseline), and deep, moderate and light stages of sedation. Short-delay recognition tasks were performed under these four sedative stages, followed by long-delay recognition tasks after participants recovered from sedation. The results of the short-delay recognition task showed that the performance was lowest at the deep stage. The performance of the moderate stage was lower than the baseline. In the long-delay recognition task, the performance under moderate sedation was lower than that under baseline and light sedation. In addition, the performance under light sedation was lower than that under baseline. These results suggest that task performance becomes difficult under half sedation and that transferring information to long-term memory is difficult even under one-quarter sedation.

Paradoxical boosting of weak and strong spatial memories by hippocampal dopamine uncaging.

The ability to remember changes in the surroundings is fundamental for daily life. It has been proposed that novel events producing dopamine release in the hippocampal CA1 region could modulate spatial memory formation. However, the role of hippocampal dopamine increase on weak or strong spatial memories remains unclear. We show that male mice exploring two objects located in a familiar environment for 5 minutes created a short-term memory (weak) that cannot be retrieved one day later, whereas 10 minutes exploration created a long-term memory (strong) that can be retrieved one day later. Remarkably, hippocampal dopamine elevation during the encoding of weak object location memories (OLMs) allowed their retrieval one day later but dopamine elevation during the encoding of strong OLMs promoted the preference for a familiar object location over a novel object location after 24 hours. Moreover, dopamine uncaging after the encoding of OLMs did not have effect on weak memories whereas on strong memories diminished the exploration of the novel object location. Additionally, hippocampal dopamine elevation during the retrieval of OLMs did not allow the recovery of weak memories and did not affect the retrieval of strong memory traces. Finally, dopamine elevation increased hippocampal theta oscillations, indicating that dopamine promotes the recurrent activation of specific groups of neurons. Our experiments demonstrate that hippocampal dopaminergic modulation during the encoding of OLMs depends on memory strength indicating that hyperdopaminergic levels that enhance weak experiences could compromise the normal storage of strong memories.Significance statement Increased levels of dopamine have been related to cognitive enhancement. Hippocampal dopamine elevation caused by novelty exposure has been proposed as a strategy to enhance memory based on the observation that surprising events create flashbulb memories that are remembered for long time. However, hyperdopaminergic levels could also underlie maladaptive memories, such as non-desired preservation of traumatic experiences. Our experiments show that dopamine elevation in the dorsal hippocampus during the encoding of spatial memories has paradoxical effects, while the enhancement of weak memories allows their retrieval, the dopaminergic modulation of strong memories limits the ability to modify preexisting spatial memories by changes in the environment. We conclude that cognitive enhancement through dopamine boosting must consider diverse aspects of memory formation.

Consolidation of emotional memory during waking rest depends on trait anxiety.

A short period of eyes-closed waking rest improves long-term memory for recently learned information, including declarative, spatial, and procedural memory. However, the effect of rest on emotional memory consolidation remains unknown. This preregistered study aimed to establish whether post-encoding rest affects emotional memory and how anxiety levels might modulate this effect. Participants completed a modified version of the dot-probe attention task that involved reacting to and encoding word stimuli appearing underneath emotionally negative or neutral photos. We tested the effect of waking rest on memory for these words and pictures by manipulating the state that participants entered just after this task (rest vs. active wake). Trait anxiety levels were measured using the State-Trait Anxiety Inventory and examined as a covariate. Waking rest improved emotional memory consolidation for individuals high in trait anxiety. These results suggest that the beneficial effect of waking rest on memory extends into the emotional memory domain but depends on individual characteristics such as anxiety.

A Simple Tube Escape Assay to Test Learning and Memory in Zebrafish with Minimized Habituation.

Various methods have been used in rodents to evaluate learning and memory. Although much less frequently used, the zebrafish emerges as an alternative model organism in this context. For example, it allows assessing potential behavioral deficits because of neurodevelopmental disorders or environmental neurotoxins. A variety of learning tasks have been employed in previous studies that required extensive habituation and training sessions. Here, we introduce a simpler and faster method to evaluate learning and memory of zebrafish with minimum habituation. A new apparatus, a transparent L-shaped tube, was developed in which we trained each zebrafish to swim through a long arm and measured the time to swim through this arm. We demonstrate that in this task, zebrafish could acquire both short-term (1 h) and long-term memory (4 days). We also studied learning and memory of a gene knockout (KO) zebrafish that showed social impairments related to autism. We found KO mutant zebrafish to show a quantitative impairment in habituation, learning, and memory performance compared with wild-type control fish. In conclusion, we established a novel learning apparatus and sensitive paradigm that allowed us to evaluate learning and memory of adult zebrafish that required only a brief habituation period and minimal training.

When Load is Low, Working Memory is Shielded From Long-Term Memory's Influence.

Previous studies found that episodic long-term memory (eLTM) enhances working memory (WM) performance when both novel and previously learnt word pairs must be retained on a short-term basis. However, there is uncertainty regarding how and when WM draws on eLTM. Three possibilities are (a) that people draw on eLTM only if WM capacity is exceeded; (b) that there is always a contribution of eLTM to WM performance, irrespective of whether prior knowledge is helpful or not; or (c) benefits of prior knowledge are specific to comparisons between conditions which are similarly ambiguous concerning whether LTM may be useful. We built on the assumption that under conditions of a contribution from LTM, these LTM traces of memoranda could benefit or hamper performance in WM tasks depending on the match between the traces stored in LTM and the ones to-be stored in WM in the current trial, yielding proactive facilitation (PF) and proactive interference (PI), respectively. Across four experiments, we familiarized participants with some items before they completed a separate WM task. In accordance with possibility (a) we show that there are indeed conditions in which only WM contributes to performance. Performance deteriorated with the addition of stimuli from eLTM when WM load was low, but not when it was high; and an exchange of information between LTM and WM occurred only when WM capacity was exceeded, with PI and PF effects affecting immediate memory performance in verbal and visual tasks only at higher set sizes.

Temporal multiplexing of perception and memory codes in IT cortex.

A central assumption of neuroscience is that long-term memories are represented by the same brain areas that encode sensory stimuli1. Neurons in inferotemporal (IT) cortex represent the sensory percept of visual objects using a distributed axis code2-4. Whether and how the same IT neural population represents the long-term memory of visual objects remains unclear. Here we examined how familiar faces are encoded in the IT anterior medialface patch (AM), perirhinal face patch (PR) and temporal pole face patch (TP). In AM and PR we observed that the encoding axis for familiar faces is rotated relative to that for unfamiliar faces at long latency; in TP this memory-related rotation was much weaker. Contrary to previous claims, the relative response magnitude to familiar versus unfamiliar faces was not a stable indicator of familiarity in any patch5-11. The mechanism underlying the memory-related axis change is likely intrinsic to IT cortex, because inactivation of PR did not affect axis change dynamics in AM. Overall, our results suggest that memories of familiar faces are represented in AM and perirhinal cortex by a distinct long-latency code, explaining how the same cell population can encode both the percept and memory of faces.

Behavioral signatures of the rapid recruitment of long-term memory to overcome working memory capacity limits.

Working- and long-term memory are often studied in isolation. To better understand the specific limitations of working memory, effort is made to reduce the potential influence of long-term memory on performance in working memory tasks (e.g., asking participants to remember artificial, abstract items rather than familiar real-world objects). However, in everyday life we use working- and long-term memory in tandem. Here, our goal was to characterize how long-term memory can be recruited to circumvent capacity limits in a typical visual working memory task (i.e., remembering colored squares). Prior work has shown that incidental repetitions of working memory arrays often do not improve visual working memory performance - even after dozens of incidental repetitions, working memory performance often shows no improvement for repeated arrays. Here, we used a whole-report working memory task with explicit rather than incidental repetitions of arrays. In contrast to prior work with incidental repetitions, in two behavioral experiments we found that explicit repetitions of arrays yielded robust improvement to working memory performance, even after a single repetition. Participants performed above chance at recognizing repeated arrays in a later long-term memory test, consistent with the idea that long-term memory was used to rapidly improve performance across array repetitions. Finally, we analyzed inter-item response times and we found a response time signature of chunk formation that only emerged after the array was repeated (inter-response time slowing after two to three items); thus, inter-item response times may be useful for examining the coordinated interaction of visual working and long-term memory in future work.

The Preisach model of hysteresis: fundamentals and applications

Abstract The Preisach model is a well-known model of hysteresis in the modern nonlinear science. This paper provides an overview of works that are focusing on the study of dynamical systems from various areas (physics, economics, biology), where the Preisach model plays a key role in the formalization of hysteresis dependencies. Here we describe the input-output relations of the classical Preisach operator, its basic properties, methods of constructing the output using the demagnetization function formalism, a generalization of the classical Preisach operator for the case of vector input-output relations. Various generalizations of the model are described here in relation to systems containing ferromagnetic and ferroelectric materials. The main attention we pay to experimental works, where the Preisach model has been used for analytic description of the experimentally observed results. Also, we describe a wide range of the technical applications of the Preisach model in such fields as energy storage devices, systems under piezoelectric effect, models of systems with long-term memory. The properties of the Preisach operator in terms of reaction to stochastic external impacts are described and a generalization of the model for the case of the stochastic threshold numbers of its elementary components is given.

The role of culture and semantic organization in working memory updating

ABSTRACT Westerners tend to relate items in a categorical manner, whereas Easterners focus more on functional relationships. The present study extended research on semantic organization in long-term memory to working memory. First, Americans’ and Turks’ preferences for categorical versus functional relationships were tested. Second, working memory interference was assessed using a 2-back working memory paradigm in which lure items were categorically and functionally related to targets. Next, a mediation model tested direct effects of culture and semantic organization on working memory task behaviour, and the indirect effect, whether semantic organization mediated the relationship between culture and working memory interference. Whereas Americans had slower response times to correctly rejecting functional lures compared to categorical lures, conditions did not differ for Turks. However, semantic organization did not mediate cultural difference in working memory interference. Across cultures, there was evidence that semantic organization affected working memory errors, with individuals who endorsed categorical more than functional pairings committing more categorical than functional errors on the 2-back task. Results align with prior research suggesting individual differences in use of different types of semantic relationships, and further that literature by indicating effects on interference in working memory. However, these individual differences may not be culture-dependent.

Paradoxical Long-term Memory Augmentation following Temporal Pairing between "Limited" and "Extensive" Motor Sequence Training Experiences.

Consecutive training on two movement sequences often leads to retroactive interference-obstructing memory for the initially trained sequence but not for the second. However, in the context of hippocampal-system dependent memories, a poor learning experience, memory for which would soon decay, can be enhanced if temporally paired with a "strong," memory triggering experience. The synaptic tagging and capture hypothesis explains this paradoxical enhancement by suggesting that only strong experiences generate cellular resources necessary for synaptic remodeling. However, synapses engaged in a "weak" learning experience can capture and utilize plasticity-related resources generated for a subsequent strong learning experience. Here, we tested whether such "paradoxical" outcome would result in the context of motor (procedural) memory, if two movement sequences are unequally trained, consecutively. We show, in young adults (n = 100), that limited practice on a novel sequence of finger-to-thumb opposition movements led to different long-term outcomes, depending on whether and when (5 min, 5 hr) it was followed by extensive training on a different sequence. Five-minute pairing, only, resulted in overnight gains for the limited-trained sequence that were well-retained a week later; the overnight gains for the extensively trained sequence were compromised. Thus, consecutive training on different motor tasks can result in mnemonic interactions other than interference. We propose that the newly discovered mnemonic interaction provides the first-tier behavioral evidence in support of the possible applicability of notions stemming from the synaptic tagging and capture hypothesis in relation to human motor memory generation, specifically in relation to the practice-dependent consolidation of novel explicitly instructed movement sequences.

Long-Term Implicit Epigenetic Stress Information in the Enteric Nervous System and its Contribution to Developing and Perpetuating IBS.

Psychiatric and mood disorders may play an important role in the development and persistence of irritable bowel syndrome (IBS). Previously, we hypothesized that stress-induced implicit memories may persist throughout life via epigenetic processes in the enteric nervous system (ENS), independent of the central nervous system (CNS). These epigenetic memories in the ENS may contribute to developing and perpetuating IBS. Here, we further elaborate on our earlier hypothesis. That is, during pregnancy, maternal prenatal stresses perturb the HPA axis and increase circulating cortisol levels, which can affect the maternal gut microbiota. Maternal cortisol can cross the placental barrier and increase cortisol-circulating levels in the fetus. This leads to dysregulation of the HPA axis, affecting the gut microbiota, microbial metabolites, and intestinal permeability in the fetus. Microbial metabolites, such as short-chain fatty acids (which also regulate the development of fetal ENS), can modulate a range of diseases by inducing epigenetic changes. These mentioned processes suggest that stress-related, implicit, long-term epigenetic memories may be programmed into the fetal ENS during pregnancy. Subsequently, this implicit epigenetic stress information from the fetal ENS could be conveyed to the CNS through the bidirectional microbiota-gut-brain axis (MGBA), leading to perturbed functional connectivity among various brain networks and the dysregulation of affective and pain processes.

Verbal learning in frontal patients: area 9 is critical for employing semantic strategies.

Learning is a long-term memory process heavily influenced by the control processes implemented by working memory, including recognition of semantic properties of items by which subjects generate a semantic structure of engrams. The aim of this study is to investigate the verbal learning strategies of patients affected by a tumor in the left frontal lobe to highlight the role of area 9. Ten patients with frontal low-grade gliomas and ten healthy control subjects, matched for age, sex and education, were recruited and then evaluated with a two-part verbal learning test: multi-trial word list learning in free recall, and multi-trial word list learning preceded by an explicit semantic strategy cue. Frontal patients were divided into two groups: those either with frontal lesions involving or sparing area 9. In comparison to healthy control subjects, frontal patients with lesions involving area 9 memorized fewer words and displayed difficulty in using semantic strategies. When the strategy was suggested by the examiner, their performance improved, but to a lesser extent than the healthy control. Conversely, frontal patients with lesions sparing area 9 showed similar results to healthy control subjects. The results suggested that, while the identification of the categorical criterion requires the integrity of the entire dorsolateral prefrontal area, only area 9, and not the surrounding areas, could be responsible for the effective use of semantic strategies in learning tasks.

Deep Long and Short Term Memory with Tunicate Swarm Algorithm for Skin Disease Detection and Classification

The development and implementation of cost-effective and efficient screening technologies is important. To address these concerns, we have introduced a unique method to detect skin diseases. Each photo is first pre-processed and cropped to pixel size. Six square fields are used to split these pictures into pixels. Techniques for enlarging images, such as rotation, mirroring, and enhancement, are employed to minimize the quantity of parameters needed for further processes. An kernel-weighted fuzzy local information or the C-means clustering model (K-FCM) is used to properly segment cancer-affected regions. Texture and colour features are then extracted. Finally, a deep long-term and short-term memory (DLTM)-based tunicate group algorithm (TSA) is used to detect skin diseases and classify both normal and abnormal classes. The experiment was carried out using MATLAB, and photos were gathered from the Helllev University Hospital in Denmark. According to the comparative analysis results, the proposed DLSTM-TSA outperforms competing products in terms of F-score, sensitivity, and precision.

Specific exercise patterns generate an epigenetic molecular memory window that drives long-term memory formation and identifies ACVR1C as a bidirectional regulator of memory in mice

Exercise has beneficial effects on cognition throughout the lifespan. Here, we demonstrate that specific exercise patterns transform insufficient, subthreshold training into long-term memory in mice. Our findings reveal a potential molecular memory window such that subthreshold training within this window enables long-term memory formation. We performed RNA-seq on dorsal hippocampus and identify genes whose expression correlate with conditions in which exercise enables long-term memory formation. Among these genes we found Acvr1c, a member of the TGF ß family. We find that exercise, in any amount, alleviates epigenetic repression at the Acvr1c promoter during consolidation. Additionally, we find that ACVR1C can bidirectionally regulate synaptic plasticity and long-term memory in mice. Furthermore, Acvr1c expression is impaired in the aging human and mouse brain, as well as in the 5xFAD mouse model, and over-expression of Acvr1c enables learning and facilitates plasticity in mice. These data suggest that promoting ACVR1C may protect against cognitive impairment.

Triune Nanomodulator Enables Exhausted Cytotoxic T Lymphocyte Rejuvenation for Cancer Epigenetic Immunotherapy.

Oncogene activation and epigenome dysregulation drive tumor initiation and progression, contributing to tumor immune evasion and compromising the clinical response to immunotherapy. Epigenetic immunotherapy represents a promising paradigm in conquering cancer immunosuppression, whereas few relevant drug combination and delivery strategies emerge in the clinic. This study presents a well-designed triune nanomodulator, termed ROCA, which demonstrates robust capabilities in tumor epigenetic modulation and immune microenvironment reprogramming for cancer epigenetic immunotherapy. The nanomodulator is engineered from a nanoscale framework with epigenetic modulation and cascaded catalytic activity, which self-assembles into a nanoaggregate with tumor targeting polypeptide decoration that enables loading of the immunogenic cell death (ICD)-inducing agent. The nanomodulator releases active factors specifically triggered in the tumor microenvironment, represses oncogene expression, and initiates the type 1 T helper (TH1) cell chemokine axis by reversing DNA hypermethylation. This process, together with ICD induction, fundamentally reprograms the tumor microenvironment and significantly enhances the rejuvenation of exhausted cytotoxic T lymphocytes (CTLs, CD8+ T cells), which synergizes with the anti-PD-L1 immune checkpoint blockade and results in a boosted antitumor immune response. Furthermore, this strategy establishes long-term immune memory and effectively prevents orthotopic colon cancer relapse. Therefore, the nanomodulator holds promise as a standalone epigenetic immunotherapy agent or as part of a combination therapy with immune checkpoint inhibitors in preclinical cancer models, broadening the array of combinatorial strategies in cancer immunotherapy.

The impact of working memory testing on long-term associative memory.

The long-term fate of to-be-remembered information depends in part on the conditions of initial learning, including mental operations engaged via working memory. However, the mechanistic role of working memory (WM) processes in subsequent episodic memory (EM) remains unclear. Does re-exposure to word-pairs during WM recognition testing improve EM for those associations? Are benefits from WM re-exposure greater after an opportunity for retrieval practice compared to mere re-exposure to the memoranda? These questions are addressed in three experiments (N = 460) designed to assess whether WM-based recognition testing benefits long-term associative memory relative to WM-based restudying. Our results show null or negative benefits of WM recognition testing minutes later when initial WM accuracy was not considered. An EM benefit of WM recognition testing only emerges when the analyses are limited to pairs responded to correctly during WM. However, even when compared with accurate WM recognition, restudying can lead to similar associative EM benefits in specific experimental conditions. Taken together, the present results suggest that while WM re-exposure to studied pairs is beneficial to long-term associative memory, successful retrieval on initial tests may be a necessary but insufficient condition for the emergence of a "WM-based testing effect." We consider these results in relation to several hypotheses proposed to explain the testing effect in long-term memory (LTM). In view of empirical parallels with the LTM testing effect, we propose that similar processes influence the benefits of practice tests administered within the canonical boundaries of WM, suggesting continuities in memory over the short and long term.