Variability across subjects in free recall versus cued recall.

Memory scientists usually compare mean performance on some measure(s) (accuracy, confidence, latency) as a function of experimental condition. Some researchers have made within-subject variability in task performance a focal outcome measure (e.g., Yao et al., Journal of Clinical and Experimental Neuropsychology, 38, 227-237, 2016). Here, we explored between-subject variability in accuracy as a function of experimental conditions. This work was inspired by an incidental finding in a previous study, in which we observed greater variability in accuracy of memory performance on cued recall (CR) versus free recall (FR) of English animal/object nouns (Mah et al., Frontiers in Psychology, 14, 1146200, 2023). Here we report experiments designed to assess the reliability of that pattern and to explore its causes (e.g., differential interpretation of instructions, [un]relatedness of CR word pairs, encoding time). In Experiment 1 (N = 120 undergraduates), we replicated the CR:FR variability difference with a more representative set of English nouns. In Experiments 2A (N = 117 Prolific participants) and 2B (N = 127 undergraduates), we found that the CR:FR variability difference persisted in a forced-recall procedure. In Experiment 3 (N = 260 Prolific participants), we used meaningfully related word pairs and still found greater variability in CR than in FR performance. In Experiment 4 (N = 360 Prolific participants), we equated CR and FR study phases by having all participants study pairs and, again, observed greater variability in CR than FR. The same was true in Experiment 5 (N = 120 undergraduates), in which study time was self-paced. Comparisons of variability across subjects can yield insights into the mechanisms underlying task performance.

A direct replication and extension of Popp and Serra (2016, experiment 1): better free recall and worse cued recall of animal names than object names, accounting for semantic similarity.

Introduction: Free recall tends to be better for names of animate concepts such as animals than for names of inanimate objects. In Popp and Serra's 2016 article, the authors replicated this "animacy effect" in free recall but when participants studied words in pairs (animate-animate pairs intermixed with inanimate-inanimate pairs) and were tested with cued recall, performance was better for inanimate-inanimate pairs than for animate-animate pairs ("reverse animacy"). We tested the replicability of this surprising effect and one possible explanation for the effect (semantic similarity). Methods: Our Experiment 1 was a preregistered direct replication (N = 101) of Popp and Serra's Experiment 1 (mixed-lists condition). In a second preregistered experiment conducted in four different samples (undergraduate N = 153, undergraduate N = 143, online Prolific N = 101, online Prolific/English-as-a-first-language N = 150), we manipulated the within-category semantic similarity of animal and object wordlists. Results: AIn Experiment 1, just as in Popp and Serra, we observed an animacy effect for free recall and a reverse animacy effect for cued recall. Unlike Popp and Serra, we found that controlling for interference effects rendered the reverse animacy effect non-significant. We took this as evidence that characteristics of the stimulus sets (e.g., category structure, within-category similarity) may play a role in animacy and reverse animacy effects. In Experiment 2, in three out of our four samples, we observed reverse animacy effects when within-category similarity was higher for animals and when within-category similarity was equated for animals and objects. Discussion: Our results suggest that the reverse animacy effect observed in Popp and Serra's 2016 article is a robust and replicable effect, but that semantic similarity alone cannot explain the effect.

Transcranial Electrical Stimulation for Associative Memory Enhancement: State-of-the-Art from Basic to Clinical Research.

Associative memory (AM) is the ability to bind new information into complex memory representations. Noninvasive brain stimulation (NIBS), especially transcranial electric stimulation (tES), has gained increased interest in research of associative memory (AM) and its impairments. To provide an overview of the current state of knowledge, we conducted a systematic review following PRISMA guidelines covering basic and clinical research. Out of 374 identified records, 41 studies were analyzed-twenty-nine in healthy young adults, six in the aging population, three comparing older and younger adults, as well as two studies on people with MCI, and one in people with Alzheimer's dementia. Studies using transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS) as well as oscillatory (otDCS) and high-definition protocols (HD-tDCS, HD-tACS) have been included. The results showed methodological heterogeneity in terms of study design, stimulation type, and parameters, as well as outcome measures. Overall, the results show that tES is a promising method for AM enhancement, especially if the stimulation is applied over the parietal cortex and the effects are assessed in cued recall paradigms.

The role of rehearsal and reminding in the recall of categorized word lists.

Most theories of free recall emphasize the importance of retrieval in explaining temporal and semantic regularities in recall; rehearsal mechanisms are often absent or limit rehearsal to a subset of what was last rehearsed. However, in three experiments using the overt rehearsal method, we show clear evidence that just-presented items act as retrieval cues during encoding (study-phase retrieval) with prior related items rehearsed despite well over a dozen intervening items. Experiment 1 examined free recall of categorized and uncategorized lists of 32 words. In Experiments 2 and 3, we presented categorized lists of 24, 48, and 64 words for free recall or cued recall, with the category exemplars blocked in successive list positions (Experiment 2) or randomized throughout the list (Experiment 3). The probability of rehearsing a prior word was affected by its semantic similarity to the just-presented item, and the frequency and recency of its prior rehearsals. These rehearsal data suggest alternative interpretations to well-known recall phenomena. With randomized designs, the serial position curves were reinterpreted by when words were last rehearsed (which contributed to the list length effects), and semantic clustering and temporal contiguity effects at output were reinterpreted by whether words were co-rehearsed during study. The contrast with the blocked designs suggests that recall is sensitive to the relative (not absolute) recency of targeted list items. We discuss the benefits of incorporating rehearsal machinery into computational models of episodic memory, and suggest that the same retrieval processes that generate the recalls are used to generate the rehearsals.

The benefit of retrieval practice on cued recall under stress depends on item difficulty.

Retrieval practice, the act of recalling previously studied information, yields greater memory retention than repeated studying (retrieval practice effect). Retrieval practice can also protect memories against the negative effects of stress at retrieval in free recall tests. In cued-recall tests, however, retrieval practice may not provide complete protection against stress-related memory impairments. Here we ask whether these conflicting results may be explained by the relative difficulty of the study materials. Participants (59 men) first studied 40 Swahili-Portuguese word pairs. Half of the pairs were then repeatedly studied while the other half were repeatedly recalled. In each condition, half of the pairs were easy to remember (high in memorability) while the other half were more difficult to remember (low in memorability). Participants returned 1 week later for a final cued-recall test. Half of the participants underwent a stress-induction protocol (modified Socially Evaluated Cold Pressor Test) 25 min before the final test for all 40-word pairs; the other half underwent a control condition. Salivary cortisol and questionnaire responses were used to assess the efficacy of stress induction. Participants recalled more word pairs learned via retrieval practice than via repeated study, replicating previous research. More importantly, the results revealed an interaction such that stress decreased recall for easy items, but increased recall for difficult items that had been successfully retrieved during encoding (conditional analysis). The results suggest that the impact of stress on cued recall depends both on the learning strategy and on the intrinsic difficulty of the to-be-learned materials.

Development of the neural correlates of recollection.

Recollection of past events has been associated with the core recollection network comprising the posterior medial temporal lobe and parietal regions, as well as the medial prefrontal cortex (mPFC). The development of the brain basis for recollection is understudied. In a sample of adults (n = 22; 18-25 years) and children (n = 23; 9-13 years), the present study aimed to address this knowledge gap using a cued recall paradigm, known to elicit recollection experience. Successful recall was associated with activations in regions of the core recollection network and frontoparietal network. Adults exhibited greater successful recall activations compared with children in the precuneus and right angular gyrus. In contrast, similar levels of successful recall activations were observed in both age groups in the mPFC. Group differences were also seen in the hippocampus and lateral frontal regions. These findings suggest that the engagement of the mPFC in episodic retrieval may be relatively early maturing, whereas the contribution to episodic retrieval of more posterior regions such as the precuneus and angular gyrus undergoes more protracted maturation.

Within-pair factors might explain the inconsistent effects of animacy on paired-associates recall.

The tendency for people to have better memory for animate (living) concepts than inanimate (nonliving) concepts in memory tasks involving free recall and recognition suggests that animacy status can be an important predictor of memory. To date, however, the effect of animacy on paired-associates recall has been mixed: Some studies have found an animacy advantage, some have found an animacy disadvantage, and some have found no difference by animacy. We tested the hypothesis that the within-pair relationship of the two words in a pair matters more for cued recall than animacy itself. In two experiments, college students studied animate and inanimate English word pairs for a cued-recall test. We varied whether the pairs involved two typical exemplars from the same category (e.g., SALMON-TROUT; FORK-SPOON), one typical and one atypical exemplar from the same category (e.g., DOCTOR-SCIENTIST; HOUSE-IGLOO), or two unrelated words from different categories (e.g., SERGEANT-COBRA; MAGAZINE-PLIERS). Respectively, these pair types produced an animacy disadvantage, an animacy advantage, and no difference by animacy in both experiments. We then examined several measures of within-pair similarity for the items. All were positively associated with paired-associates recall, but animacy had no effect on cued recall above and beyond the relationship of these measures to recall. These results suggest that the within-pair relationship matters more for cued recall than does animacy. Uneven variation in within-pair relationships for animate versus inanimate pairs-rather than animacy itself-might therefore produce the apparently inconsistent effects of animacy on paired-associates recall.

A modified Cued Recall Test for detecting prodromal AD in adults with Down syndrome.

Introduction: The development of valid methods to diagnose prodromal Alzheimer's disease (AD) in adults with Down syndrome (DS) is one of the many goals of the Alzheimer's Biomarkers Consortium-Down Syndrome (ABC-DS). Methods: The diagnostic utility of a modified Cued Recall Test (mCRT) was evaluated in 332 adults with DS ranging from 25 to 81 years of age. Total recall was selected a priori, as the primary indicator of performance. Multiple regression and receiver-operating characteristic (ROC) analyses were used to compare diagnostic groups. Results: Performance on the mCRT, as indicated by the total recall score, was highly sensitive to differences between diagnostic groups. ROC areas under the curve (AUCs) ranging from 0.843 to 0.955, were observed. Discussion: The mCRT has strong empirical support for its use in clinical settings, as a valuable tool in studies targeting biomarkers of AD, and as a potential outcome measure in clinical trials targeting AD in this high-risk population.

Time-of-day effects on eyewitness reports in morning and evening types.

Our performance varies throughout the day as a function of alignment with our circadian rhythms. The current experiment tested whether similar performance patterns can be observed in eyewitness memory performance. One-hundred-and-three morning-type and evening-type participants watched a stimulus event, provided a free report and answered cued questions in the morning and the evening hours, respectively. We expected eyewitness reports to be more detailed and more accurate at participants' circadian peaks than at circadian troughs. Contrary to our predictions, time of testing did not significantly affect quantity and accuracy of eyewitness statements. Future studies might investigate whether matching chronotype with time of day would be beneficial when encoding or retrieval conditions are suboptimal or when eyewitnesses are vulnerable.

Characterization of memory profile in idiopathic REM sleep behavior disorder.

OBJECTIVE: The present study aims to examine whether declarative memory dysfunction relates to impaired core memory mechanisms or attentional and executive dysfunction in idiopathic REM Sleep Behavior Disorder (iRBD). METHOD: In this observational, cross-sectional study, were enrolled 82 individuals with the diagnosis of iRBD according to the International Classification of Sleep Disorders and 49-matched healthy controls fulfilling inclusion criteria. All participants underwent two memory tasks, namely the Rey Auditory Verbal Learning Test (RAVLT) and Memory Binding Test (MBT), which include conditions of varying degrees of dependence on executive functioning, as well as different indicators of core memory processes (e.g., learning, retention, relational binding). RESULTS: We used Bayesian multivariate generalized linear model analysis to evaluate the effect of iRBD on memory performance controlled for effects of age and sex. Individuals with iRBD displayed worse memory performance in the delayed free recall task (b = -0.37, 95% PPI [-0.69, -0.05]), but not on delayed recognition of the same material. Their performance in cued recall tasks both in immediate and delayed conditions was in comparison to controls relatively spared. Moreover, the deficit in delayed free recall was mediated by attention/processing speed. CONCLUSIONS: In iRBD, we replicated findings of reduced free recall based on inefficient retrieval (retrieval deficit), which was small in terms of effect size. Importantly, the memory profile across measures does not support the presence of core memory dysfunction, such as poor learning, retention or associative binding.

Swap errors in visual working memory are fully explained by cue-feature variability.

In cue-based recall from working memory, incorrectly reporting features of an uncued item may be referred to as a "swap" error. One account of these errors ascribes them to variability in memory for the cue features leading to erroneous selection of a non-target item, especially if it is similar to the target in the cue-feature dimension. However, alternative accounts of swap errors include cue-independent misbinding, and strategic guessing when the cued item is not in memory. Here we investigated the cause of swap errors by manipulating the variability with which either cue or report features (orientations in Exp 1; motion directions in Exp 2) were encoded. We found that swap errors increased with increasing variability in memory for the cue features, and their changing frequency could be quantitatively predicted based on recall variability when the same feature was used for report. These results are inconsistent with the hypothesis that swaps are a strategic response to forgotten items, and suggest that swap errors could be wholly accounted for by confusions due to cue-dimension variability. In a third experiment we examined whether spatial configuration of memory arrays in tasks with spatial cueing has an influence on swap error frequency. We observed a specific tendency to make swap errors to non-targets located precisely opposite to the cued location, suggesting that stimulus positions are partially encoded in a non-metric format.

Modified cued recall test in the French population with Down syndrome: A retrospective medical records analysis.

BACKGROUND: Adults with Down syndrome (DS) are at increased risk of developing Alzheimer's disease (AD) due to genetic predisposition. Identification of patients with AD is difficult since intellectual disabilities (ID) may confound diagnosis. The objective of this study was to evaluate the ability of the French version of the modified cued recall test (mCRT) to distinguish between subjects with and without AD in the adult DS population. METHODS: This was a retrospective, single-centre, medical records study including data between March 2014 and July 2020. Adults aged ≥30 years with DS who had at least one mCRT record available were eligible. Age, sex and ID level were extracted, and subjects were attributed to three groups: patients with AD, patients with co-occurring conditions that may impact cognitive function and subjects without AD. mCRT scores, adjusted by sex, age and ID level, were compared between groups. The optimal cut-off value to distinguish between patients with and without AD was determined using the receiver operating characteristic curve. The impact of age and ID level on mCRT scores was assessed. RESULTS: Overall, 194 patients with DS were included: 12 patients with AD, 94 patients with co-occurring conditions and 88 healthy subjects. Total recall scores were significantly lower (P < 0.0001) in patients with AD compared with healthy subjects. The optimal cut-off value to discriminate between patients with AD and healthy subjects was 22, which compares well with the cut-off value of 23 originally reported for the English version of the mCRT. Patients aged 30-44 years had higher mCRT total recall scores compared with patients aged ≥45 years (P = 0.0221). Similarly, patients with mild ID had higher mCRT scores compared with patients with severe ID (P < 0.0001). INTERPRETATION: The mCRT is a sensitive tool that may help in the clinical diagnosis of AD in subjects with DS. Early recognition of AD is paramount to deliver appropriate interventions to this vulnerable population.

Reactivity from judgments of learning is not only due to memory forecasting: evidence from associative memory and frequency judgments.

Research has shown that judgments of learning (JOLs) often produce a reactive effect on the learning of cue-target pairs in which target recall differs between participants who provide item-based JOLs at study versus those who do not. Positive reactivity, or the memory improvement found when JOLs are provided, is typically observed on related pairs, while no reactivity is commonly found on unrelated pairs. In four experiments, we examined JOL reactivity effects by comparing JOL and no-JOL groups to other groups who engaged in relational-type encoding/judgment tasks. Experiment 1 replicated positive JOL reactivity effects with related pairs with an extension to symmetrically related pairs. Next, Experiment 2 found that providing judgments of associative memory-a task that does not involve memory predictions-yielded equivalent reactivity patterns as JOLs. Experiment 3 replicated this reactivity pattern using a frequency of co-occurrence judgment task. Finally, In Experiment 4, a similar positive reactivity pattern was found using a relational encoding task when compared to a standard JOL. Collectively, our results suggest that previous JOL reactivity patterns are not solely due to memory forecasting processes via JOLs and likely reflect relational encoding that is strategically applied towards related, but not unrelated pairs. Supplementary Information: The online version contains supplementary material available at 10.1007/s11409-022-09301-2.

Effect of Whey-Derived Lactopeptide ß-Lactolin on Memory in Healthy Adults: An Integrated Analysis of Data from Randomized Controlled Trials.

CONTEXT: Epidemiological studies have shown that consumption of dairy products reduces the risk of dementia and cognitive decline in older individuals. Tryptophan-tyrosine-related ß-lactopeptides and their representative ß-lactolin of glycine-threonine-tryptophan-tyrosine tetra-peptide have been identified as agents in dairy products, which improve cognitive function as well as memory function via the activation of the dopaminergic system in a mouse model of amnesia. Previous clinical trials have shown that supplementation with ß-lactolin improves memory retrieval in healthy older adults. Specifically, ß-lactolin improved the scores in some neuropsychological tests. However, the effects of ß-lactolin on memory function have not been clarified. OBJECTIVES: The aim of this study was to evaluate the effect of ß-lactolin on memory function using statistical methods. DATA SOURCES: We searched the Web of Science, Cochrane Library, and JDream III until November 2021 to identify relevant randomized controlled trials for integrated analysis. DATA SYNTHESIS: Three randomized controlled trials evaluating the effect of ß-lactolin on memory in healthy adults were selected for the integrated analysis. The results showed that the score of cued recall among the neuropsychological tests in the ß-lactolin group was significantly higher than that in the placebo group (g=0.33; 95% CI: 0.10, 0.55). In addition, the total memory score was higher but this difference was not significant (g=0.17; 95% CI: -0.09, 0.43). CONCLUSIONS: Taken together, these results suggest that supplementation with ß-lactolin improves cued recall in healthy older adults.

The lrd package: An R package and Shiny application for processing lexical data.

Recall testing is a common assessment to gauge memory retrieval. Responses from these tests can be analyzed in several ways; however, the output generated from a recall study typically requires manual coding that can be time intensive and error-prone before analyses can be conducted. To address this issue, this article introduces lrd (Lexical Response Data), a set of open-source tools for quickly and accurately processing lexical response data that can be used either from the R command line or through an R Shiny graphical user interface. First, we provide an overview of this package and include a step-by-step user guide for processing both cued- and free-recall responses. For validation of lrd, we used lrd to recode output from cued, free, and sentence-recall studies with large samples and examined whether the results replicated using lrd-scored data. We then assessed the inter-rater reliability and sensitivity and specificity of the scoring algorithm relative to human-coded data. Overall, lrd is highly reliable and shows excellent sensitivity and specificity, indicating that recall data processed using this package are remarkably consistent with data processed by a human coder.

Prior episodic learning and the efficacy of retrieval practice.

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.

Norm Determination Study of Trail Making Test, Enhanced Cued Recall Test and Clock Drawing Test for Turkish Sample Between 6-18 Years of Age.

INTRODUCTION: The aim of this study was to determine the developmental stages-specific normative values of Trial Making Test (TMT), Enhanced Cued Recall Test (ECRT) and Clock Drawing Test (CDT) which are commonly used in adults for the evaluation of cognitive functions affected by psychiatric and neurological diseases and developmental disorders for a healthy Turkish sample between 6-18 years of age. METHOD: A total of 249 primary and secondary school students between 6-18 years of age and living in Ankara and educated in public and/or private schools participated in the study. Primary analysis was conducted by appropriate ANOVA and/or MANOVA for 2 (Developmental Stage: Middle-Late Childhood (6-11 years) and Adolescence (12-18 years)) x 2 (Gender: Female and Male) factorial design. In addition, another group of ANOVA and/or MANOVA analyses for 3 (Adolescence Sub-Stages) x 2 (Gender) was also performed for the adolescence stage that was sub-grouped as early (12-13 years), middle (14-15 years) and late (16+ years). RESULTS: Normative values were determined both for two different developmental stages and for the adolescence sub-stages. Comparisons indicated that main effect of gender and interactions were non-significant for all tests. On the other hand, the main effects of the developmental stage and adolescence sub-stages were significant for many of the test scores. CONCLUSION: As a result of the study, three neuropsychological tests and their normative values for children and adolescents were presented as available for use in future research.

Impaired performances on the category cued memory test in mild Alzheimer's disease and dementia with Lewy bodies: A comparative validity study.

Cued recall taps amnesia of "the hippocampal type" as typically found in Alzheimer's disease (AD). Studies investigating the validity of cued recall measures in AD have typically been conducted in research settings. The Category Cued Memory Test (CCMT-48) measures learning/memory using the same categories during encoding and acquisition. The aim of this study was to investigate how frequently impairments were found on the CCMT-48 mild AD patients from a memory clinic (N = 77). We used a case-oriented approach where individually observed scores were compared to expected scores derived from regressions-based normative data. We also investigated if CCMT-48 performances differed in patients with mild AD and Dementia with Lewy Bodies (DLB) (N = 90). The results showed a significantly higher frequency of impairment in the AD group as compared to the DLB group for scores below 10th percentile-estimate (impaired: AD 88%; DLB 69%) and 5th percentile-estimate (impaired: AD 82%; DLB 53%). In conclusion, a very high frequency of impairment of a picture-based cued recall test in AD patients (very high sensitivity) in a memory clinic setting. However, specificity is not optimal since impairments also frequently occurred in DLB where memory problems could be assumed to be part of attentional deficits and poor retrieval strategies.

Imagery-based strategies for memory for associations.

Cued recall of word pairs is improved by asking participants to combine items in an interactive image. Meanwhile, interactive images facilitate serial-recall (Link Method), but even better when each item is imagined alongside a previously learned peg-word (Peg List Method). We asked if a peg system could support memory for pairs, hypothesising it would outperform interactive imagery. Tested with cued recall, five study strategies were manipulated between-subjects, across two experiments: (1) Both words linked to one peg; (2) Each word linked to a different peg; (3) Peg list method but studying as a serial list; (4) Interactive imagery (within-pairs); (5) Link Method. Participants were able to apply peg-list strategies to pairs, as anticipated by mathematical modelling. Error-patterns spoke to mathematical models; peg lists exhibited distance-based confusability, characteristic of positional-coding models, and errors tended to preserve within-pair position, even for inter-item associative strategies, suggesting models of association should incorporate position. However, the peg list strategies came with a speed-accuracy tradeoff and did not challenge the superiority of the interactive imagery strategy. Without extensive practice with peg list strategies, interactive imagery remains superior for associations. Peg strategies may excel instead in tasks that primarily test serial order or with extensive training.

Self-referential encoding does not benefit memory for prior remembering across changing contexts.

Changes in context across instances of memory retrieval have been shown to impair memory for acts of prior remembering. The present study examined how self-referential encoding influences memory for prior remembering that occurred with or without context change. At encoding, participants processed each target in cue-target word pairs in relation to themselves or another person. During an initial cued-recall test, targets were tested with either the studied cues or semantically related, but previously unseen cues. During a second cued-recall test, all targets were tested with the studied cues, and participants judged whether they remembered retrieving each target during the first test. Regardless of self/other-reference, semantic context change across the two tests impaired memory for prior remembering. Furthermore, the magnitude of this impairment was larger for strongly self-associated vs. other-associated targets. Our findings suggest that self-referential encoding does not benefit memory for prior remembering in the face of contextual change.