Spaced practice in declarative memory tasks consistently yields greater learning than massed practice, but spacing effects are less consistently observed for motor skills. This study evaluates factors that may determine spacing effects on motor skill learning, including: (1) extant theories of declarative spacing effects, (2) reactive inhibition, which transiently impairs performance and may also impair learning, and (3) the micro-consolidation hypothesis, which posits that motor skill learning takes place exclusively during brief performance breaks. Across two experiments, we varied the number of correct sequences per trial and the length of breaks during training, while keeping the total correct sequence count constant, using a widely studied motor sequence task. A pronounced performance advantage was observed for the spaced groups by the end of training. However, on a later test in which the task conditions were equated, group performance was statistically indistinguishable. Hence, spaced practice yielded no or minimal learning advantage and the large reactive inhibition effect in the massed group appears to be a transient performance phenomenon without consequence for learning. Furthermore, we found no evidence for the most straightforward micro-consolidation account, which predicts greater learning with more breaks. Our results are consistent with a simple account advanced by Gupta and Rickard1,2, according to which learning occurs entirely online (i.e., concurrently with performance) and is independent of spacing and reactive inhibition. Finally, our findings indicate that proposed mechanisms for declarative spacing effects, such as memory reactivation and contextual variability, do not generalize to motor learning, highlighting fundamental differences between the two learning systems.

Retrieval practice (i.e., practice testing) enhances recall relative to other study methods, but it is still unclear when it helps most. Here, we ask if testing is more beneficial for weakly or strongly related word pairs. Participants studied word pairs with either low or high semantic relatedness, then practiced them using either test-with-feedback or restudy. We gave a final cued-recall test 24 hours later. Rather than relying on an ANOVA interaction on proportion correct, which can be hard to interpret when the link between latent memory strength and accuracy is unknown, we evaluated performance using a principled reference model and used cumulative distribution matching. Testing improved recall in both groups, but its benefit was 26% smaller for highly related pairs. This pattern was not explained by ceiling constraints, either across participants or at the item level. The model's characteristic quadratic relation between test and restudy performance held, but the high-relatedness data showed a systematic reduction in the incremental gain from testing. One interpretation consistent with the model is that study and test memory strengths become positively correlated for highly related materials. These results clarify how semantic structure shapes the testing effect and when practice testing is likely to pay off most.

Motor skill learning and performance is driven by the interplay between declarative and nondeclarative systems, which can complement or interfere with one another depending on task demands. In this study, we investigated whether an intervening declarative cued-recall task impairs motor skill performance in a finger-tapping-task and assessed three hypotheses: the consolidation disruption hypothesis, the shared resource hypothesis, and the breakdown of inhibition hypothesis. Intervening declarative tasks placed late in training failed to affect motor performance. In contrast, when introduced early in training (Experiment 3), motor performance appears to have been transiently impaired. Despite this impairment, there was no association between the intervening declarative task performance and motor impairment. We discuss the ramifications of these findings with regard to other motor skill tasks and intervening declarative tasks.

The present study investigated the cognitive processing architecture of dual(-memory) retrieval from a single cue across two distinct age groups: younger and older adults. Previous research has shown that younger adults can exhibit learned parallel retrieval, but only if they synchronize response execution. This phenomenon has not been demonstrated with older adults. Experiment 1 functioned as an extension of previous studies to assess whether the finding of learned retrieval parallelism in younger adults could be observed in older adults as well. The experiment used a dual retrieval task that involved the retrieval of two responses, one vocal and one keypress, from a single cue. Experiment 2 further assessed whether the cognitive processing architecture underlying the occurrence of learned retrieval parallelism in dual memory retrieval could be influenced by the number of cues in single-retrieval practice. The results of both experiments showed that learned retrieval parallelism occurs in older as well as younger adults and that the processing mechanisms involved in dual memory retrieval are relatively stable across age groups.

Two hypotheses have been advanced for when motor sequence learning occurs: offline between bouts of practice or online concurrently with practice. A third possibility is that learning occurs both online and offline. A complication for differentiating between those hypotheses is a process known as reactive inhibition, whereby performance worsens over consecutively executed sequences, but dissipates during breaks. We advance a new quantitative modeling framework that incorporates reactive inhibition and in which the three learning accounts can be implemented. Our results show that reactive inhibition plays a far larger role in performance than is appreciated in the literature. Across four groups of participants in which break times and correct sequences per trial were varied, the best overall fits were provided by a hybrid model. The version of the offline model that does not account for reactive inhibition, which is widely assumed in the literature, had the worst fits. We discuss implications for extant hypotheses and directions for future research.

Recall from episodic memory has been shown to enhance learning of both the retrieved information (e.g., relative to a restudy control condition; the testing effect, or TE) and subsequently studied materials (the forward testing effect, or FTE). The TE paradigm may be subject to an FTE confound when training phase testing precedes restudy, attenuating TE magnitude. Across one new cued-recall experiment and five large n cued-recall datasets from the literature, we provide evidence for that confounding effect. We further show that the predictions of the dual-memory model of TE can hold when there is and is not a confounding FTE. If there is no FTE confound, the model equation can successfully predict proportion correct in the test condition across the entire cumulative distribution. When there is an FTE confound, that prediction holds only for the lower portion of the cumulative distribution (i.e., for participants with relatively low task ability or motivation), but we show that the model can still account for proportion correct across the full distribution, provided that the prediction is based on restudy proportion correct for a matched control group that is not subject to the FTE confound. An account of the FTE confound effect is proposed, according to which a difficult test promotes more effective strategy use, particularly among higher ability participants, during subsequent restudy. Implications for testing effect theory and application are discussed. Given the greater information that the cumulative distribution analysis provides, we recommend that approach as a routine supplement to mean proportion correct.

Understanding the complex relationship between sleep and memory consolidation is a major challenge in cognitive neuroscience and psychology. Many studies suggest that sleep triggers off-line memory processes, resulting in less forgetting of declarative memory and performance stabilization in non-declarative memory. However, the role of sleep in human memory consolidation is still under considerable debate, and numerous contradictory and non-replicable findings have been reported. Methodological issues related to experimental designs, task characteristics and measurements, and data-analysis practices all influence the effects that are observed and their interpretation. In this Perspective, we review methodological issues in sleep and memory studies and suggest constructive solutions to address them. We believe that implementing these solutions in future sleep and memory research will substantially advance the field and improve understanding of the specific role of sleep in memory consolidation. Studies of the effect of sleep on learning and memory sometimes reveal conflicting or unreliable results. In this Perspective, Nemeth and colleagues review methodological challenges and make recommendations for improving the reliability of research in this field.

Recall from episodic memory has been shown to enhance both memory for the retrieved information (e.g., relative to a restudy control condition; the testing effect, or TE) and memory for different, subsequently studied materials (the forward testing effect, or FTE). Hence, the TE may be subject to an FTE confound when training in a TE experiment involves either testing prior to restudy or when restudied and tested items are randomly mixed. Across two cued-recall TE experiments, we show that (1) a potent FTE confound exists in the test-first but not the mixed training design, (2) there are no other learning related interactions between restudied and tested items across three frequently used training phase task orderings, and (3) the predictions of the dual-memory model of test-enhanced learning hold both when there is and is not a confounding FTE. Further, our results yielded no evidence for two accounts of the FTE (the proactive interference and reset of encoding hypotheses) as applied to cued recall but are consistent with two alternative accounts (the strategy change and increasing effort hypotheses). Through distribution analyses we identify a novel and potent individual differences effect for the FTE that is consistent with the latter accounts. Finally, we show that at least three large-n individual difference studies are confounded by the FTE, compromising conclusions in those papers about the efficacy of the TE across individuals in applied contexts.

Several recent papers have advanced the hypothesis that motor sequence learning occurs during breaks between performance trials rather than during performance itself. Here, we advance an alternative hypothesis in which motor learning occurs concurrently with performance and that reactive inhibition – which has a progressive slowing effect on performance during each trial but dissipates during breaks – operates with equivalent magnitude across trials, yielding the illusion that learning occurs during breaks across the range of early training trials on which analyses were conducted in the recent studies. We advance a quantitative model of motor sequence practice effects that embodies our assumptions and provides a close fit to data at the grain-size of sequences within-trials. Our modeling approach supports a level of predictive precision and theoretical transparency that in our view should be the standard in future work on this topic.

Understanding the complex relationship between sleep and memory is a major challenge in neuroscience. Many studies on memory consolidation in humans suggest that sleep triggers offline memory processes, resulting in less forgetting of declarative memory and performance stabilization in non-declarative memory. However, an increasing number of contradictory findings reveal potential issues with how research is conducted in this field and call into question the reliability and interpretation of the results. All scientific disciplines face similar challenges. In this regard, research on the relationship between sleep and memory is still very fortunate. Yet, there is a constant need to fine-tune the methodology. In this article, we describe four behavioral methodological issues in human sleep and memory research that should be improved: non-optimal experimental designs, task complexity, fatigue effects in repetitive tasks, and inappropriate data analysis practices. We then offer solutions to each of these issues. We believe that implementing these solutions in future sleep and memory research will lead to more reliable results and significantly advance our understanding in this field.

In three experiments we investigated how the level of study-based, episodic knowledge influences the efficacy of subsequent retrieval practice (testing) as a learning event. Possibilities are that the efficacy of a test, relative to a restudy control, decreases, increases, or is independent of the degree of prior study-based learning. The degree of study-based learning was manipulated by varying the number of item repetitions in the initial study phase between one and eight. Predictions of the dual-memory model of test-enhanced learning for the case of one study-phase repetition were used as a reference. Results support the hypothesis that the advantage of testing over restudy is independent of the degree of prior episodic learning, and they suggest that educators can apply cued-recall testing with the expectation that its efficacy is similar across varying levels of prior content learning. Implications for testing effect theory are discussed.

The prevailing hypothesis for observed post-rest motor reaction time improvements is offline consolidation. In the present study, we present evidence for an alternate account involving the accrual and dissipation of reactive inhibition. Four groups of participants (N=159) performed a finger tapping task involving either massed (30 s per trial) or spaced (10 s per trial) training, and with one of two break intervals between each trial: 10 s or 30 s. After 360 s of training in each group, there was a 300 s rest period followed by a final test on the same task. The results show that the smaller the ratio of break time to on-task trial time during training, the larger the improvement in reaction time after the rest period. Those results are fully consistent with a model that assumes no facilitating offline consolidation, but rather learning that is concurrent with performance and reactive inhibition that builds during performance and dissipates during breaks.

We explored the possibility of publication bias in the sleep and explicit motor sequence learning literature by applying precision effect test (PET) and precision effect test with standard errors (PEESE) weighted regression analyses to the 88 effect sizes from a recent comprehensive literature review (Pan & Rickard, 2015). Basic PET analysis indicated pronounced publication bias; that is, the effect sizes were strongly predicted by their standard error. When variables that have previously been shown to both moderate the sleep gain effect and substantially reduce unaccounted for effect size heterogeneity were included in that analysis, evidence for publication bias remained strong. The estimated postsleep gain was negative, suggesting forgetting rather than facilitation, and it was statistically indistinguishable from the estimated postwake gain. In a qualitative review of a smaller group of more recent studies we observed that (a) small sample sizes-a major factor behind the publication bias-are still the norm, (b) use of demonstrably flawed experimental design and analysis remains prevalent, and (c) when authors conclude in favor of sleep-dependent consolidation, they frequently do not cite the articles in which those methodological flaws have been demonstrated. We conclude that there is substantial publication bias, that there is no consolidation-based, absolute performance gain following sleep, and that strong conclusions regarding the hypothesis of less forgetting after sleep than after wakefulness should await further research. Recommendations are made for reducing publication bias in future work. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

A century ago, spelling skills were highly valued and widely taught in schools using traditional methods, such as weekly lists, drill exercises, and low- and high-stakes spelling tests. That approach was featured in best-selling textbooks such as the Horn-Ashbaugh Speller of 1920. In the early 21st century, however, skepticism as to the importance of spelling has grown, some schools have deemphasized or abandoned spelling instruction altogether, and there has been a proliferation of non-traditional approaches to teaching spelling. These trends invite a reevaluation of the role of spelling in modern English-speaking societies and whether the subject should be explicitly taught (and if so, what are research-supported methods for doing so). In this article, we examine the literature to address whether spelling skills are still important enough to be taught, summarize relevant evidence, and argue that a comparison of common approaches to spelling instruction in the early 20th century versus more recent approaches provides some valuable insights. We also discuss the value of explicit spelling instruction and highlight potentially effective ways to implement such instruction, including the use of spelling tests. Overall, our goals are to better characterize the role of spelling skills in today’s society and to identify several pedagogical approaches—some derived from traditional methods and others that are more recent—that hold promise for developing such skills in efficient and effective ways.

Understanding the complex relationship between sleep and memory is a major challenge in neuroscience. Thousands of studies on memory consolidation in humans suggest that sleep triggers offline memory processes, resulting in less forgetting of declarative memory and performance stabilization in non-declarative memory. However, an increasing number of contradictory findings reveal potential issues with how research is conducted in this field and call into question the reliability and interpretation of the results. In this consensus paper, we describe four sets of prevalent methodological pitfalls in human sleep and memory research: (i) non-optimal experimental designs, (ii) task complexity, (iii) fatigue effects in repetitive tasks, and (iv) inappropriate data analysis practices. We then offer solutions to each of these pitfalls. We believe that implementing these solutions in future research of sleep and memory will lead to more reliable results and significantly advance our understanding in this field.

A century ago, spelling skills were highly valued and widely taught in schools using traditional methods, such as weekly lists, drill exercises, and low- and high-stakes spelling tests. That approach was featured in best-selling textbooks such as the Horn-Ashbaugh Speller of 1920. In the early 21st century, however, skepticism as to the importance of spelling has grown, some schools have deemphasized or abandoned spelling instruction altogether, and there has been a proliferation of non-traditional approaches to teaching spelling. These trends invite a reevaluation of the role of spelling in modern English-speaking societies and whether the subject should be explicitly taught (and if so, what are research-supported methods for doing so). In this article we examine the literature to address whether spelling skills are still important enough to be taught, summarize relevant evidence, and argue that a comparison of common approaches to spelling instruction in the early 20th century versus more recent approaches provides some valuable insights. We also discuss the value of explicit spelling instruction and highlight potentially effective ways to implement such instruction, including the use of spelling tests. Overall, our goals are to better characterize the role of spelling skills in today’s society and to identify several pedagogical approaches—some derived from traditional methods and others that are more recent—that hold promise for developing such skills in efficient and effective ways.

The dual-memory model of test-enhanced learning (Rickard & Pan, 2018, Psychonomic Bulletin & Review, 25[3], 847-869) provides empirically supported quantitative predictions about multiple core phenomena for the case of cued recall. That model has been evaluated to date only for mean proportion correct. However, it also makes predictions about the distribution over subjects for both test-condition proportion correct and testing-effect magnitude. As a consequence, it makes predictions about aggregate individual difference effects on learning through testing. The current paper evaluates those and other predictions, focusing on a data set of 509 subjects aggregated over multiple experiments that were conducted in my laboratory. Results show that the distribution predictions hold to a close approximation for materials ranging from paired associates to history facts, and for retention intervals ranging from 1 to 7 days. The distribution analyses also allow for a novel assessment of whether accuracy on a training test with feedback is a determinant of testing-effect magnitude, and the results suggest constraints on alternative models. Limitations and prospects are discussed.

In four experiments, we explored conditions under which learning due to retrieval practice (i.e., testing) transfers to the case in which the cue and response words are rearranged (e.g., a training test on gift, rose, ?, wherein the target is wine, and a final test on gift, ?, wine, wherein the answer is rose). In both Experiment 1 and a supplementary experiment, we observed divergent results for pairs and triplets: Relative to a restudy control condition, strong transfer was observed for pairs, but none for triplets. In Experiments 2 and 3, the theoretical basis of the specificity of learning for triplets was explored. The results rule out the possibilities that transfer is wholly absent for triplets and that transfer occurs only for the case of exact cue–response reversal on the final test. Rather, it appears that, for both pairs and triplets, transfer will occur unless both of the following conditions hold: (1) two or more independent cues are presented on the training test, and (2) the correct responses on the training and final tests are different. We show that the majority of the results can be explained by combining the dual-memory theory of the testing effect with an inclusive-OR representation that forms when two or more cues are presented on the training test. Follow-up analyses that were conditionalized on training test accuracy suggest that specificity of learning is greater on a correct than on an incorrect training test trial, although selection confounds and contradictory experimental results preclude a strong conclusion.

Repeatedly switching between a series of to-be-learned topics, also called interleaved practice (interleaving), can improve learning over traditional, one-topic-at-a-time blocked practice (blocking). We investigated whether interleaving’s benefits for foreign language learning are facilitated by random schedules, wherein training trials follow unpredictable patterns, or systematically alternating schedules, wherein trials are predictably sorted. Students learned to conjugate Spanish verbs in the preterite and imperfect tenses and then took a 48-hr. delayed verb conjugation test. A consistently random (Experiment 1) or systematically alternating schedule (Experiment 2) did not improve learning versus blocking. However, the combination of both types – systematic alternation for study trials and randomization for practice trials – enhanced learning (Experiments 3-4). Thus, neither interleaving schedule alone appears to be sufficient; for verb conjugation skills and likely other materials involving study followed by problem-solving practice, both are needed. Interleaving’s benefits are therefore impacted by the alignment between training schedule and task type.