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.

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.

Associative asymmetry of the recognition without cued-recall effect in thematic relations.

In the present study, two experiments were conducted to examine whether thematic relation can produce recognition without cued-recall effect and whether the direction of the association has an influence on this effect. The participants provided higher familiarity ratings for studied items than for unstudied items during target retrieval failure. Additionally, the thematic relation-elicited recognition without cued-recall effect was larger in the forward association than in the backward association. Collectively, these results indicated that thematic relations can elicit the recognition without cued-recall effect, and this effect is asymmetrical. The current findings support the features overlap hypothesis described in the global match model.

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.

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.

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.

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.

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.

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.

Recallable but not recognizable: The influence of semantic priming in recall paradigms.

When people can successfully recall a studied word, they should be able to recognize it as having been studied. In cued-recall paradigms, however, participants sometimes correctly recall words in the presence of strong semantic cues but then fail to recognize those words as actually having been studied. Although the conditions necessary to produce this unusual effect are known, the underlying neural correlates have not been investigated. Across five experiments, involving both behavioral and electrophysiological methods (EEG), we investigated the cognitive and neural processes that underlie recognition failures. Experiments 1 and 2 showed behaviorally that assuming that recalled items can be recognized in cued-recall paradigms is a flawed assumption, because recognition failures occur in the presence of cues, regardless of whether those failures are measured. With event-related potentials (ERPs), Experiments 3 and 4 revealed that successfully recalled words that are recognized are driven by recollection at recall and then by a combination of recollection and familiarity at ensuing recognition. In contrast, recognition failures did not show that memory signature and may instead be driven by semantic priming at recall and followed at recognition stages by negative-going ERP effects consistent with implicit processes, such as repetition fluency. These results demonstrate that recall - long-characterized as predominantly reflecting recollection-based processing in episodic memory - may at times also be served by a confluence of implicit cognitive processes.

Episodic Memory Impairment in Parkinson's Disease: Disentangling the Role of Encoding and Retrieval.

OBJECTIVE: The source of episodic memory (EM) impairment in Parkinson's disease (PD) is still unclear. In the present study, we sought to quantify specifically encoding, consolidation, and retrieval process deficits in a list-learning paradigm by a novel method, the item-specific deficit approach (ISDA). METHODS: We applied the ISDA method to the Free and Cued Selective Reminding Test (FCSRT) in a sample of 15 PD patients and 15 healthy participants. RESULTS: The results revealed differences in free recall performance between PD patients and controls. These patients, however, benefited from cues as much as controls did, and total recall did not differ between groups. When analyzing the ISDA indices for encoding, consolidation, and retrieval deficits, the results showed a general memory deficit, but with a clear focus on encoding and retrieval, as revealed by the sensitivity values. Moreover, controlling for initial learning did not eliminate group effects in retrieval. CONCLUSIONS: Our findings reveal a mixed pattern in PD patients, with deficits in both encoding and retrieval processes in memory. Also, despite the fact that an encoding dysfunction may explain some of the deficits observed at retrieval, it cannot fully account for the differences, highlighting that both encoding and retrieval factors are necessary to understand memory deficits in PD.

Construing events first-hand: Gesture viewpoints interact with speech to shape the attribution and memory of agency.

Beyond conveying objective content about objects and actions, what can co-speech iconic gestures reveal about a speaker's subjective relationship to that content? The present study explores this question by investigating how gesture viewpoints can inform a listener's construal of a speaker's agency. Forty native English speakers watched videos of an actor uttering sentences with different viewpoints-that of low agency or high agency-conveyed through both speech and gesture. Participants were asked to (1) rate the speaker's responsibility for the action described in each video (encoding task) and (2) complete a surprise memory test of the spoken sentences (recall task). For the encoding task, participants rated responsibility near ceiling when agency in speech was high, with a slight dip when accompanied by gestures of low agency. When agency in speech was low, responsibility ratings were raised markedly when accompanied by gestures of high agency. In the recall task, participants produced more incorrect recall of spoken agency when the viewpoints expressed through speech and gesture were inconsistent with one another. Our findings suggest that, beyond conveying objective content, co-speech iconic gestures can also guide listeners in gauging a speaker's agentic relationship to actions and events.

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.

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.

Multimodal Integration and Vividness in the Angular Gyrus During Episodic Encoding and Retrieval.

Much evidence suggests that the angular gyrus (AnG) is involved in episodic memory, but its precise role has yet to be determined. We examined two possible accounts within the same experimental paradigm: the "cortical binding of relational activity" (CoBRA) account (Shimamura, 2011), which suggests that the AnG acts as a convergence zone that binds multimodal episodic features, and the subjectivity account (Yazar et al., 2012), which implicates AnG involvement in subjective mnemonic experience (such as vividness or confidence). fMRI was used during both encoding and retrieval of paired associates. During study, female and male human participants memorized picture-pairs of common objects (in the unimodal task) or of an object-picture and an environmental sound (in the crossmodal task). At test, they performed a cued-recall task and further indicated the vividness of their memory. During retrieval, BOLD activation in the AnG was greatest for vividly remembered associates, consistent with the subjectivity account. During encoding, the same effect of vividness was found, but this was further modulated by task: greater activations were associated with subsequent recall in the crossmodal than the unimodal task. Therefore, encoding data suggest an additional role to the AnG in crossmodal integration, consistent with its role at retrieval proposed by CoBRA. These results resolve some of the puzzles in the literature and indicate that the AnG can play different roles during encoding and retrieval as determined by the cognitive demands posed by different mnemonic tasks.SIGNIFICANCE STATEMENT We offer new insights into the multiplicity of processes that are associated with angular gyrus (AnG) activation during encoding and retrieval of newly formed memories. We used fMRI while human participants learned and subsequently recalled pairs of objects presented to the same sensory modality or to different modalities. We were able to show that the AnG is involved when vivid memories are created and retrieved, as well as when encoded information is integrated across different sensory modalities. These findings provide novel evidence for the contribution of the AnG to our subjective experience of remembering alongside its role in integrative processes that promote subsequent memory.

Mechanisms of output interference in cued recall.

The primary aim of this paper is to elucidate the mechanisms governing output interference in cued recall. Output interference describes the phenomenon where accuracy decrease over the course of an episodic memory test. Output inference in cued recall takes the form of a decrease in correct and intrusion responses and an increase in failures to response across the test. This pattern can only be accounted for by a model with two complementary mechanisms: learning during retrieval and a response filter that prevents repeated recall of the same item. We investigate how a retrieval filter might operate by manipulating the similarity of words. The data are consistent with a retrieval filter that does not operate by a global match of a potential target to previously recalled items. Results are discussed within the search of associative memory theory.

Reversing the testing effect by feedback is a matter of performance criterion at practice.

Retrieval practice is generally considered to be one of the most effective long-term learning strategies and is presumed to be more favorable than repeated study. However, a few recent studies have demonstrated that repetitive feedback at final recall can reverse the long-term advantage of testing over restudy. The result that feedback at long-term tests can dramatically decrease the relative effectiveness of retrieval-based learning could be important for both theoretical and practical reasons. Considering that these earlier studies administered low retrieval success at retrieval practice, we investigated whether the effect of feedback on the testing effect is modulated by the level of retrieval success during practice. In three experiments the level of success at retrieval practice was manipulated by multiple pre-practice learning trials, and multiple tests with feedback were applied after a 1-week retention interval at final recall. Our results have demonstrated that a feedback-induced reversed testing effect was present only at low retrieval success during practice (Experiment 1), whereas with moderate (Experiment 2) and high retrieval success (Experiment 3) during practice a significant testing effect emerged and no reversed testing effect was found even after repeated cycles of feedback. These results point to the conclusion that the level of retrieval success was the key factor in reversing the testing effect in earlier studies. Application of high retrieval success during practice can produce long-lasting accessible memories even in learning settings applying multiple tests with feedback.

Affect enhances object-background associations: evidence from behaviour and mathematical modelling.

In recognition memory paradigms, emotional details are often recognised better than neutral ones, but at the cost of memory for peripheral details. We previously provided evidence that, when peripheral details must be recalled using central details as cues, peripheral details from emotional scenes are at least as likely to be recalled as those from neutral scenes. Here we replicated and explicated this result by implementing a mathematical modelling approach to disambiguate the influence of target type, scene emotionality, scene valence, and their interactions. After incidentally encoding scenes that included neutral backgrounds with a positive, negative, or neutral foreground objects, participants showed equal or better cued recall of components from emotional scenes compared to neutral scenes. There was no evidence of emotion-based impairment in cued recall in either of two experiments, including one in which we replicated the emotion-induced memory trade-off in recognition. Mathematical model fits indicated that the emotionality of the encoded scene was the primary driver of improved cued-recall performance. Thus, even when emotion impairs recognition of peripheral components of scenes, it can preserve the ability to recall which scene components were studied together.

Performance on an Associative Memory Test Decreases 8 hr After Cardiovascular Exercise.

This study was designed to assess the effects of acute exercise on performance of a paired associate learning (PAL) test, an operationalization of hippocampal-dependent associative memory. Participants performed a PAL test and then ran on a treadmill (exercise group, n = 52) or solved Sudoku puzzles (control group, n = 54). Participants returned 2, 5, or 8 hr later to perform a second, different, PAL test. PAL scores for the control group did not change over time. Similarly, scores on tests taken 2 and 5 hr after exercise were not different from baseline or control data. Scores on tests taken 8 hr after exercise, however, fell significantly below baseline (by 8.6%) and control (by 9.8%) scores. These data demonstrate that acute exercise can negatively affect the encoding and retrieval of new information even hours after the exercise bout, which should be a consideration when designing exercise programs to enhance, and not hinder, learning.

Normative data for Chinese-English paired associates.

Paired-associate learning is one of the most commonly used paradigms to study human memory. In many of these studies, participants are typically told to learn foreign language-English translations, such as Swahili-English or Lithuanian-English pairs. One limitation of these currently available foreign language-English translation norms is that their foreign languages are based on the alphabetic writing system, thereby preventing researchers from generalizing their findings to languages based on logographic writing systems. In the present study we collected normative data for 160 Chinese-English word pairs. Participants completed three study-test cycles, followed by metacognitive judgments on their learning experience. For each pair, we report recall performance, recall latency, ease of learning, and judgments of learning. A simultaneous multiple regression analysis with frequency (of both the English word and the Chinese character), word length (English), and number of strokes (Chinese) as predictors revealed that a greater number of strokes (or higher visual complexity) for the Chinese characters predicted lower target recall.