Disruption of the serial position effect as an early marker of Alzheimer's disease in Spanish-English bilinguals.

OBJECTIVES: The present study examined if disruption of serial position effects in list recall could serve as an early marker of Alzheimer's disease (AD) in Spanish-English bilinguals. METHODS: We tested 20 participants initially diagnosed as cognitively normal or with mild cognitive impairment who declined and eventually received a diagnosis of AD (decliners), and 37 who remained cognitively stable (controls) over at least 2 years. Participants were tested on the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Word List Learning Test in English or Spanish as part of an annual neuropsychological evaluation. RESULTS: Compared to controls, decliners exhibited significantly reduced recall including reduced primacy scores (i.e., items recalled from the first three list items on Trial 1), whereas recency scores (i.e., items recalled from the last 3 list items on Trial 1) were equivalent in decliners and controls. Further analyses suggested that the sensitivity of the primacy effect to preclinical AD was initially stronger in participants tested in Spanish, a surprising finding given that the CERAD was developed for English speakers. However, in the subsequent year of testing, primacy scores declined to the same level regardless of language of testing. CONCLUSIONS: Several list learning measures may facilitate early diagnosis of AD in Spanish-English bilinguals, possibly including the relatively understudied primacy effect. Additional studies are needed to investigate the possibility that linguistic or demographic variables might modulate sensitivity of list learning tests to preclinical AD, which could lead to broader improvements in their utility for early diagnosis of AD in all populations.

Intentional and incidental odour-colour binding in working memory.

The question of how features are bound together in working memory has become a topic of much research in recent years. However, this is typically focused on visual and/or auditory stimuli. The purpose of this study is to apply established feature binding procedures to investigate odour binding in working memory. Across three experiments, memory for intentionally and incidentally formed odour-colour pairings was tested. Experiment 1 showed that following explicit instruction to remember the odour-colour combinations, young adults can recall lists of 3-pairings at levels above that of chance and exhibit a recency advantage for the last pairing. In Experiment 2 participants were asked to prioritise the first pairing in the list or treat all pairings equally. We observed only limited evidence of prioritisation affecting the serial position function. Experiment 3 explored incidental odour-colour binding. Using a yes/no recognition procedure, accuracy did not differ for positive test probes presented in the same (bound) or different (unbound) colour to encoding. This study is one of the first to examine odour-colour binding in working memory and, taking the evidence together, suggests that odour-colour bindings can be formed in working memory; however, functionality may be limited compared to that of visual feature binding.

How retrieval practice and semantic generation affect subsequently studied material: an analysis of item-level effects.

The forward testing effect (FTE) refers to the finding that retrieval practice of previously studied material can facilitate recall of newly studied (critical) material. Such interim retrieval practice can also lead to a differential FTE, i.e., a more pronounced FTE for items at early than later serial positions in the critical material. The present study examined whether this differential FTE also holds with interim semantic generation of extra-list items, and whether it is influenced by study material. Consistent with prior work, the results of two experiments showed that both interim retrieval practice and interim semantic generation induce the general (list-level) FTE when unrelated study lists are applied, whereas retrieval practice only creates the effect with categorised study lists. Critically, however, the differential FTE was present in response to retrieval practice but absent in response to semantic generation. This pattern held regardless of which material was studied, thus experimentally dissociating the general (list-level) from the differential (item-level) FTE. The findings may suggest that retrieval practice, but not semantic generation, induces a reset of the encoding process which promotes attentional encoding such that a more pronounced FTE arises for early than middle and late serial positions in the critical list.

Metacognitive control, serial position effects, and effective transfer to self-paced study.

Serial position effects involve the differential recall of information based on its temporal order at encoding. Previous research indicates that learners may be aware of these effects under certain encoding conditions, but it is unclear whether metacognitive control is sensitive to serial position effects. The current study examined whether there are serial position effects in participants' study time and whether they can learn about serial position effects under fixed encoding conditions and then transfer what they have learned to self-paced study conditions. Specifically, participants were given lists of to-be-remembered words and studied each word for a fixed duration on initial lists, but self-paced their study time on later lists. Results revealed that self-paced study times oppositely mirrored serial position effects (i.e., briefer study times in the beginning and end of each list), and serial position effects were reduced in self-paced study conditions, particularly in participants initially studying under fixed conditions before self-pacing their study time. Specifically, participants may have monitored their output and, based on observations of forgetting middle items, transferred their learning of serial position effects from prior lists. Thus, participants may use forgetting and serial position information to guide encoding, indicating that fundamental properties of the memory system can be incorporated into the processes that guide metacognitive control.

Encoding dynamics in free recall: Examining attention allocation with pupillometry.

In four experiments pupillary responses were used to examine attention allocation and encoding dynamics in free recall. In Experiment 1, pupillary responses increased (and then decreased) across serial position suggesting that attention was increasingly allocated to items during learning until working memory was overloaded. In Experiment 2, manipulating presentation duration resulted in larger and more sustained pupillary responses with increased presentation duration, suggesting that participants were likely engaging in more elaborative and attention-demanding processes. In Experiment 3a, manipulating list-length resulted in decreased pupillary responses across serial position suggesting that participants were prioritizing early list items and less attention was allocated to later items. In Experiment 3b, when list-length was known, pupillary responses in the long-list length condition tended to decrease across serial position whereas pupillary responses in the short list-length condition tended to increase and decrease across serial positon. These results suggest that participants flexibly allocate attention to items during encoding depending on the nature of the task and the types of processes that are engaged in. These results further suggest the potential of utilizing pupillary responses to track attention allocation during learning.

How do recall requirements affect decision-making in free recall initiation? A linear ballistic accumulator approach.

Models of free recall describe free recall initiation as a decision-making process in which items compete to be retrieved. Recently, Osth and Farrell (Psychological Review, 126, 578-609, 2019) applied evidence accumulation models to complete RT distributions and serial positions of participants' first recalls in free recall, which resulted in some novel conclusions about primacy and recency effects. Specifically, the results of the modeling favored an account in which primacy was due to reinstatement of the start-of-the-list, and recency was found to be exponential in shape. In this work, we examine what happens when participants are given alternative recall instructions. Prior work has demonstrated weaker primacy and greater recency when fewer items are required to report (Ward & Tan, Memory & Cognition, 2019), and a key question is whether this change in instructions qualitatively changes the nature of the recall process, or merely changes the parameters of the recall competition. We conducted an experiment where participants studied six- or 12-item lists and were post-cued as to whether to retrieve a single item, or as many items as possible. Subsequently, we applied LBA models with various assumptions about primacy and recency, implemented using hierarchical Bayesian techniques. While greater recency was observed when only one item was required for output, the model selection did not suggest that there were qualitative differences between the two conditions. Specifically, start-of-list reinstatement and exponential recency functions were favored in both conditions.

The dynamics of memory for United States presidents in younger and older adults.

ABSTRACTSerial position effects are often observed within the free recall of unassociated words but also when recalling items from a semantic category like U.S. presidents. We investigated the dynamics of recall for U.S. presidents in younger and older adults to examine potential age-related differences in the organisation of retrieval from semantic long-term memory. Older adults recalled more presidents than younger adults and also demonstrated dual serial position effects such that, in addition to overall serial position effects, primacy (e.g., Eisenhower) and recency presidents (e.g., Obama) within older adults' lifetime were better recalled than presidents from the middle of their lives (e.g., Ford). Additionally, participants initiated recall with the most distinct presidents (highly familiar or memorable presidents like Washington, Obama, Trump), and conditional-response probabilities revealed that presidents from similar eras were recalled in close proximity, indicating that the retrieval of distinct presidents can facilitate memory for presidents from a similar era. Collectively, we demonstrate the potential interplay of the mechanisms that influence the organisation of retrieval such that distinctiveness and temporal contiguity effects may simultaneously impact recall. Specifically, semantic and temporal-contextual associations can drive semantic autobiographical memory and people likely organise retrieval from long-term memory according to familiarity and distinctiveness.

A Comparison of Serial Position Effects in Patients with Mild Cognitive Impairment due to Parkinson's Disease or to Alzheimer's Disease.

OBJECTIVE: The first (primacy region) and last (recency region) items of a word list are generally better memorized than items from the middle region. The recency effect depends on short-term memory (STM) and the primacy effect on long-term memory (LTM), where verbal information is transferred from STM into LTM by maintenance rehearsal. We compared the serial position effects (SPE) between patients with mild cognitive impairment (MCI) due to Parkinson's disease (PD), i.e., PD-MCI, and patients with MCI due to Alzheimer's disease (AD-MCI), and evaluated the influence of SPE and frontostriatal deficits on verbal memory recall. METHODS: Four similar groups of subjects participated in the study: 26 PD-MCI patients, 26 cognitively normal patients with PD (PD-CN), 26 AD-MCI patients, and 26 normal controls (NC). Verbal episodic memory, verbal span, attentional capacity, executive functions, and verbal working memory performance were assessed. Measures for primacy and recency regions were defined at the first trial of a 16-items word list. Hierarchical regression models were used to investigate the contribution of frontostriatal deficits beyond SPE on verbal memory recall performance ("long-delay free recall") in PD and AD patients. RESULTS: Primacy effects were significantly diminished in both PD-MCI and AD-MCI patients relative to NC and PD-CN (all p < 0.01). Compared to PD-MCI patients, AD-MCI patients exhibited significantly worse "delayed-recall 'savings'." Reduced primacy effect was predictive for decreased recall performance in PD and AD. The conducted hierarchical regression model revealed that in PD, but not in AD patients, performance of attention and executive function significantly increased the prediction of free recalled words. CONCLUSIONS: Reduced recall performance is likely due to impaired transition of newly learned material from STM into LTM in AD and in PD. Whereas AD-MCI patients suffer from a storage deficit, the similarly reduced recall performance found in patients with PD-MCI may additionally be related to deficient attentional and executive capacity.

Incidental learning of list membership is affected by serial position in the list.

Cowan, Donnell, and Saults [(2013). A list-length constraint on incidental item-to-item associations. Psychonomic Bulletin & Review, 20, 1253-1258] examined incidental memory of whether two words had occurred in the same list or different lists, after the lists had been presented with an orienting task that did not require memorisation. Performance was superior for 3-word lists compared to 6- or 9-word lists, with memory for the longer lists near chance levels. Here we re-examine this phenomenon with methodological modifications to ensure that learning was incidental: we removed potential clues that a memory test would follow, eliminated trials with special mnemonic cues related to the orienting task, eliminated participants who suspected a memory test according to a post-experimental questionnaire, used signal detection measures to distinguish between memory sensitivity and bias, and tested list length with the relative serial position controlled. Incidental memory formed primarily for the most recent part of each list, an effect that was stronger than that of list length. The new evidence helps to constrain theories about the relation between working memory and incidental learning. A capacity-limited approach to the incidental-learning process still is possible but must be modified compared to Cowan et al., and the evidence is favourable to other theoretical approaches as well.

Serial position-dependent false memory effects.

Evidence for false recognition within seconds of encoding suggests that semantic-associative influences are not restricted to long-term memory, consistent with unitary memory accounts but contrary to dual store models. The present study sought further relevant evidence using a modified free recall converging associates task where participants studied 12-item lists composed of 3 semantically distinct quartets (sublists) related to a separate, non-presented theme word (i.e., words 1-4/theme1, 5-8/theme2, and 9-12/theme3). This list construction permits assessment of false recall errors from each sublist, and, particularly, the primacy and recency sublists that have been linked to long- and short-term memory stores. Experiment 1 tested immediate free recall for items. Associative false memories were evident from all sublists, however, significantly less so from the recent sublist, which also showed the highest levels of veridical memory. By inserting a brief (3 s) distractor prior to recall, Experiment 2 selectively reduced veridical memory and increased false memory for the recent sublist while leaving the primacy sublist unaffected. These recall results converge with prior evidence indicating the immediacy of false recognition, and can be understood within a unitary framework where the differential availability of verbatim features and gist-based cues affect memory for primacy and recency sublists.

Similarities between the irrelevant sound effect and the suffix effect.

Although articulatory suppression abolishes the effect of irrelevant sound (ISE) on serial recall when sequences are presented visually, the effect persists with auditory presentation of list items. Two experiments were designed to test the claim that, when articulation is suppressed, the effect of irrelevant sound on the retention of auditory lists resembles a suffix effect. A suffix is a spoken word that immediately follows the final item in a list. Even though participants are told to ignore it, the suffix impairs serial recall of auditory lists. In Experiment 1, the irrelevant sound consisted of instrumental music. The music generated a significant ISE that was abolished by articulatory suppression. It therefore appears that, when articulation is suppressed, irrelevant sound must contain speech for it to have any effect on recall. This is consistent with what is known about the suffix effect. In Experiment 2, the effect of irrelevant sound under articulatory suppression was greater when the irrelevant sound was spoken by the same voice that presented the list items. This outcome is again consistent with the known characteristics of the suffix effect. It therefore appears that, when rehearsal is suppressed, irrelevant sound disrupts the acoustic-perceptual encoding of auditorily presented list items. There is no evidence that the persistence of the ISE under suppression is a result of interference to the representation of list items in a postcategorical phonological store.

Tactile Ranschburg effects: facilitation and inhibitory repetition effects analogous to verbal memory.

The present paper examines the effect of within-sequence item repetitions in tactile order memory. Employing an immediate serial recall procedure, participants reconstructed a six-item sequence tapped upon their fingers by moving those fingers in the order of original stimulation. In Experiment 1a, within-sequence repetition of an item separated by two-intervening items resulted in a significant reduction in recall accuracy for that repeated item (i.e., the Ranschburg effect). In Experiment 1b, within-sequence repetition of an adjacent item resulted in significant recall facilitation for that repeated item. These effects mirror those reported for verbal stimuli (e.g., Henson, 1998a . Item repetition in short-term memory: Ranschburg repeated. Journal of Experimental Psychology: Learning, Memory, and Cognition, 24(5), 1162-1181. doi:doi.org/10.1037/0278-7393.24.5.1162). These data are the first to demonstrate the Ranschburg effect with non-verbal stimuli and suggest further cross-modal similarities in order memory.

Recalling visual serial order for verbal sequences.

We report three experiments in which participants performed written serial recall of visually presented verbal sequences with items varying in visual similarity. In Experiments 1 and 2 native speakers of Japanese recalled visually presented Japanese Kanji characters. In Experiment 3, native speakers of English recalled visually presented words. In all experiments, items varied in visual similarity and were controlled for phonological similarity. For Kanji and for English, performance on lists comprising visually similar items was overall poorer than for lists of visually distinct items across all serial positions. For mixed lists in which visually similar and visually distinct items alternated through the list, a clear "zig-zag" pattern appeared with better recall of the visually distinct items than for visually similar items. This is the first time that this zig-zag pattern has been shown for manipulations of visual similarity in serial-ordered recall. These data provide new evidence that retaining a sequence of visual codes relies on similar principles to those that govern the retention of a sequence of phonological codes. We further illustrate this by demonstrating that the data patterns can be readily simulated by at least one computational model of serial-ordered recall, the Primacy model (Page and Norris, Psychological Review, 105(4), 761-81, 1998). Together with previous evidence from neuropsychological studies and experimental studies with healthy adults, these results are interpreted as consistent with two domain-specific, limited-capacity, temporary memory systems for phonological material and for visual material, respectively, each of which uses similar processes that have evolved to be optimal for retention of serial order.

Serial position effects are sensitive predictors of conversion from MCI to Alzheimer's disease dementia.

BACKGROUND: It is unclear whether the predictive strength of established cognitive variables for progression to Alzheimer's disease (AD) dementia from mild cognitive impairment (MCI) varies depending on time to conversion. We investigated which cognitive variables were best predictors, and which of these variables remained predictive for patients with longer times to conversion. METHODS: Seventy-five participants with MCI were assessed on measures of learning, memory, language, and executive function. Relative predictive strengths of these measures were analyzed using Cox regression models. RESULTS: Measures of word-list position-namely, serial position scores-together with Short Delay Free Recall of word-list learning best predicted conversion to AD dementia. However, only serial position scores predicted those participants with longer time to conversion. CONCLUSIONS: Results emphasize that the predictive strength of cognitive variables varies depending on time to conversion to dementia. Moreover, finer measures of learning captured by serial position scores were the most sensitive predictors of AD dementia.

Working memory prioritisation effects in tactile immediate serial recall.

There is a growing body of evidence that higher-value information can be prioritised for both visual and auditory working memory. The present study examines whether valuable items can similarly be prioritised for the tactile domain. Employing an immediate serial recall procedure (ISR), participants reconstructed a 6-item tactile sequence by moving their fingers in the order of original stimulation. Participants were informed either that one serial position was worth notionally more points (prioritisation condition) or that all items were of equal value (control condition). For Experiment 1 (N = 48), significant boosts in correct recall were evident when serial positions 4 or 5 were more valuable (i.e., prioritisation effects). Experiment 2 (N = 24) demonstrated that the prioritisation effect persisted with concurrent articulation, suggesting that task performance was not a function of verbal recoding and rehearsal of the tactile information. Importantly, a significant recall cost for low-value (non-prioritised) items within the sequence was evident for both experiments. Taken together, these findings demonstrate that (1) prioritisation effects transfer to the tactile domain and (2) finite attentional resources can be deliberately and strategically redistributed to specific items within a sequence, dependent upon the prevailing task demands.

Short-term memory for serial order supports vocabulary development: new evidence from a novel word learning paradigm.

Although recent studies suggest a strong association between short-term memory (STM) for serial order and lexical development, the precise mechanisms linking the two domains remain to be determined. This study explored the nature of these mechanisms via a microanalysis of performance on serial order STM and novel word learning tasks. In the experiment, 6- and 7-year-old children were administered tasks maximizing STM for either item or serial order information as well as paired-associate learning tasks involving the learning of novel words, visual symbols, or familiar word pair associations. Learning abilities for novel words were specifically predicted by serial order STM abilities. A measure estimating the precision of serial order coding predicted the rate of correct repetitions and the rate of phoneme migration errors during the novel word learning process. In line with recent theoretical accounts, these results suggest that serial order STM supports vocabulary development via ordered and detailed reactivation of the novel phonological sequences that characterize new words.

Using serial position effects to investigate memory dysfunction in homeless and precariously housed persons.

Background: Homeless and precariously housed persons exhibit significant memory impairment, but the component processes underlying memory dysfunction have not been explored. We examined the serial position profile (i.e., primacy and recency effects) of verbal memory and its neuroanatomical correlates to identify the nature of memory difficulties in a large cohort of homeless and precariously housed adults. Method: The sample included 227 community-dwelling homeless and precariously housed adults. Serial position scores (primacy, middle, recency) were computed using the Hopkins Verbal Learning Test-Revised. Paired sample t-tests were used to compare percent recall from each word list region. Age-adjusted correlations assessed associations between serial position scores and other cognitive domains (attention, processing speed, executive functioning). Regression analyses were conducted to examine regional brain volumes of interest (hippocampus, entorhinal cortex, dorsolateral prefrontal cortex [DLPFC]) and their differential associations with serial position scores. Results: The serial position profile was characterized by a diminished recency effect in relation to the primacy effect. Serial position scores positively correlated with sustained attention and cognitive control. Larger hippocampal volume was associated with better primacy item recall. DLPFC volume was not associated with serial position recall after adjustment for false discovery rate. There were no associations between regional brain volumes and recency item recall. Conclusion: Our results suggest that commonly reported memory difficulties in homeless and precariously housed adults are likely secondary to a core deficit in executive control due to compromised frontal lobe functioning. These findings have implications for cognitive rehabilitation in this complex and vulnerable group.

The recency ratio assessed by story recall is associated with cerebrospinal fluid levels of neurodegeneration biomarkers.

Recency refers to the information learned at the end of a study list or task. Recency forgetting, as tracked by the ratio between recency recall in immediate and delayed conditions, i.e., the recency ratio (Rr), has been applied to list-learning tasks, demonstrating its efficacy in predicting cognitive decline, conversion to mild cognitive impairment (MCI), and cerebrospinal fluid (CSF) biomarkers of neurodegeneration. However, little is known as to whether Rr can be effectively applied to story recall tasks. To address this question, data were extracted from the database of the Alzheimer's Disease Research Center at the University of Wisconsin - Madison. A total of 212 participants were included in the study. CSF biomarkers were amyloid-beta (Aß) 40 and 42, phosphorylated (p) and total (t) tau, neurofilament light (NFL), neurogranin (Ng), and α-synuclein (a-syn). Story Recall was measured with the Logical Memory Test (LMT). We carried out Bayesian regression analyses with Rr, and other LMT scores as predictors; and CSF biomarkers (including the Aß42/40 and p-tau/Aß42 ratios) as outcomes. Results showed that models including Rr consistently provided best fits with the data, with few exceptions. These findings demonstrate the applicability of Rr to story recall and its sensitivity to CSF biomarkers of neurodegeneration, and encourage its inclusion when evaluating risk of neurodegeneration with story recall.

Serial position effects and mild cognitive impairment: a comparison of measures and scoring approaches.

INTRODUCTION: Serial position effects (SPEs) have shown promise as predictors of future cognitive decline and conversion from mild cognitive impairment (MCI) to Alzheimer's disease (AD), even when accounting for total learning and memory scores. However, conflicting results have been found in the literature, which may be at least partially related to the many ways in which SPEs are calculated. The current study aimed to address the discrepancies in the literature by examining whether one method of analyzing SPEs is more sensitive at distinguishing those with and without psychometrically defined MCI. METHOD: 86 older adult participants (57 healthy comparison, 29 MCI) completed the California Verbal Learning Test, Third Edition (CVLT3) and the Rey Auditory Verbal Learning Test (RAVLT), along with measures assessing multiple cognitive domains. Each participant completed two visits, between 3 and 9 days apart, with a different memory measure administered on each day. The standard scoring approach and the regional scoring approach to calculating SPEs were compared. RESULTS: Results showed that, when significant differences were found, SPEs were always reduced in the MCI group compared to the healthy comparison group when using regional scoring; however, results were not as consistent when using standard scoring. Further, lower primacy than recency scores were only consistently seen in the MCI group when using the RAVLT but not the CVLT3. ROC analyses showed that only regional scoring of SPEs from delayed recall of the RAVLT and the CVLT3 accurately discriminated between those with and without MCI. CONCLUSION: Regional scoring of SPEs may be more sensitive at identifying subtle cognitive decline compared to standard scoring. However, the specific measure that is used to analyze SPEs can impact the interpretation of findings.

Standardized item selection for alternate computerized versions of Rey Auditory Verbal Learning Test(-based) word lists.

INTRODUCTION: Despite an increasing need for new Rey Auditory Verbal Learning Test (RAVLT)-based word lists in computerized testing, no criteria or standardized procedures exist for its development. To lay a foundation for future development of new and alternate computerized RAVLT(-based) word lists, we present cross-lingual word criteria, developed new lists using the criteria and evaluated performance on the lists using online assessment. METHOD: Based on psycholinguistic literature, we identified relevant word selection criteria. To validate the criteria, we developed two new American-English word lists and one new Dutch list, and administered the RAVLT using visual presentation of the new or original list in an online American (n = 248) and Dutch sample (n = 246) of healthy people. We compared performance of the new and original word lists on trial scores and serial position effects using Bayesian correlations and analyses of variance. Additionally, we compared proportions of correct responses per item, corrected for serial position. RESULTS: We identified 13 relevant word selection criteria. The criteria led to two new highly comparable American-English word lists with lower trial scores compared to the original American-English list, indicating that the criteria helped to develop parallel lists with fewer associations between items. The new Dutch word list showed similar trial scores, serial position effects, and proportions of correct responses per item corrected for serial position compared to the original Dutch version. CONCLUSIONS: The systematic use of word selection criteria can facilitate development of new parallel word lists, including in new language areas. Future studies should evaluate the use of the word criteria for the other sections of the RAVLT (such as delayed recall and recognition), performance using original test modalities (auditory presentation and recall of words) as well as performance in clinical samples.