Memory Binding Test and Its Associations With Hippocampal Volume Across the Cognitive Continuum Preceding Dementia

Innovative memory paradigms have been introduced to capture subtle memory changes in early Alzheimer’s disease (AD). We aimed to examine the associations between different indexes of the challenging Memory Binding Test (MBT) and hippocampal volume (HV) in a sample of individuals with subjective cognitive decline (SCD; n = 50), amnestic mild cognitive impairment (aMCI) due to AD ( n = 31), and cognitively normal (CN) older adults ( n = 29) recruited from the Czech Brain Aging Study, in contrast to traditional verbal memory tests. Both MBT free and cued recall scores in immediate and delayed recall conditions were associated with lower HV in both SCD and aMCI due to AD, whereas in traditional verbal memory tests only delayed recall scores were associated with lower HV. In SCD, the associations with lower HV in the immediate recall covered specific cued recall indexes only. In conclusion, the MBT is a promising test for detecting subtle hippocampal-associated memory decline during the predementia continuum.

The Sleep Benefit in Episodic Memory: An Integrative Review and a Meta-Analysis

People recall more information after sleep than after an equally long period of wakefulness. This sleep benefit in episodic memory has been documented in almost a century of research. However, an integrative review of hypothesized underlying processes, a comprehensive quantification of the benefit, and a systematic investigation of potential moderators has been missing so far. Here, we address these issues by analyzing 823 effect sizes from 271 independent samples that were reported in 177 articles published between 1967 and 2019. Using multilevel meta-regressions with robust variance estimates, we found a moderate overall sleep benefit in episodic memory (g = 0.44). Moderator analyses revealed four important findings: First, the sleep benefit is larger when stimuli are studied multiple times instead of just once. Second, for word materials, the effect size depends on the retrieval procedure: It is largest in free recall, followed by cued recall and recognition tasks. Third, the sleep benefit is stronger in pre-post difference measures of retention than in delayed memory tests. Fourth, sleep benefits are larger for natural sleep and nighttime naps than foralternative sleep-study designs (e.g., SWS-deprived sleep, daytime naps). Although there was no obvious evidence for selective reporting, it is a potential threat to the validity of the results. When accounting for selective reporting bias, the overall effect of sleep on episodic memory is reduced but still significant (g = 0.28). We argue that our results support an integrative, multi-causal theoretical account of sleep-induced episodic memory benefits and provide guidance to increase their replicability.

Rate of forgetting is independent of initial degree of learning

It is commonly assumed that the rate of forgetting depends on initial degree of learning. Hence, comparison of forgetting across groups is usually carried out equating initial performance. However, these matching procedures add confounding variables. In four experiments, following Slamecka and McElree (1983, Exp 3), we challenge this assumption through manipulating initial acquisition by varying the number of presentations of the material and studying the effect on rate of subsequent forgetting. A set of 36 sentences was presented either visually or auditorily. Different participants were exposed to the material two, four or six times. Forgetting was measured by means of a cued recall test at three time-intervals (30 s, 1 day and 1 week in experiments 1 and 2; 30 s, 1 day, and 3 days in experiments 3 and 4). A different subset of 12 sentences was tested at each delay. The outcome of these experiments showed that the initial acquisition depends on number of learning trials. However, the rate of forgetting proved to be independent of initial acquisition. This pattern remains constant across modalities of presentation and of the number of learning trials. The conclusion is that forgetting does not depend on initial acquisition.

Targeted Memory Reactivation during Mind-Wandering in Younger and Older Adults

Mind-wandering (MW) is a universal cognitive process that is estimated to comprise ~30% of our everyday thoughts. Despite its prevalence, the functional utility of MW remains a scientific blind spot. The present study sought to investigate whether MW serves a functional role in cognition. Specifically, we investigated whether MW contributes to memory consolidation processes, and if age differences in the ability to reactivate episodic memories during MW may contribute to age-related declines in episodic memory. Younger and older adults encoded paired associates, received targeted reactivation cues during an interval filled with a task which promotes MW, and were tested on their memory for the cued and uncued stimuli from the initial encoding task. Thought probes were presented during the retention (MW) interval to assess participants’ thought contents. Across three experiments, we compared the effect of different cue modalities (i.e., auditory, visual) on cued recall performance, and examined both correct retrieval response times as well as accuracy. Across experiments, there was evidence that stimuli that were cued during the MW task were correctly retrieved more quickly than uncued stimuli and that this effect was more robust for younger adults than older adults. Additionally, the more MW a participant reported during the retention interval, the stronger the cueing effect they produced during retrieval. The results from these experiments are interpreted within a retrieval facilitation framework wherein cues serve to reactivate the earlier traces during MW, and this reactivation benefits retrieval speed for cued items as compared to uncued items.

You won’t guess that: On the limited benefits of guessing when learning a foreign language

Guessing the meaning of a foreign word before being presented with the right answer benefits recognition performance for the translation compared to reading the full translation outright. However, guessing does not increase memory for the foreign-word-to-translation associations, which is crucial for language acquisition. In this study, we aimed to investigate whether this disadvantage of guessing for performance in cued-recall tests would be eliminated if a restudy phase was added. In Experiments 1–3, we consistently demonstrated that guessing resulted in lower cued-recall performance compared to reading, both before and after restudy. Even for items for which participants successfully recalled their initial guesses on the cued-recall test, accuracy levels did not exceed those from the reading condition. In Experiment 4, we aimed to generalize our findings concerning restudy to a different set of materials – weakly associated word pairs. Even though this time guessing led to better performance than reading, consistent with previous studies, this guessing benefit was not moderated by adding a restudy phase. Our results thus underscore the importance of the initial learning phase for future learning and retention, while undermining the usefulness of the learning-through-guessing strategy for acquiring foreign language vocabulary.

Neuropsychiatric Profile as a Predictor of Cognitive Decline in Mild Cognitive Impairment

Introduction: Mild cognitive impairment is often associated with affective and other neuropsychiatric symptoms (NPS). This co-occurrence might have a relevant impact on disease progression, from MCI to dementia.Objective: The aim of this study was to explore the trajectories of cognitive decline in an MCI sample from a memory clinic, taking into consideration a perspective of isolated cognitive functions and based on NPS clusters, accounting for the different comorbid symptoms collected at their baseline visit.Methods: A total of 2,137 MCI patients were monitored over a 2.4-year period. Four clusters of NPS (i.e., Irritability, Apathy, Anxiety/Depression and Asymptomatic) were used to run linear mixed models to explore the interaction of cluster with time on cognitive trajectories using a comprehensive neuropsychological battery (NBACE) administered at baseline and at the three subsequent follow-ups.Results: A significant interaction between cluster and time in cognitive decline was found when verbal learning and cued-recall were explored (p = 0.002 for both memory functions). For verbal learning, the Irritability cluster had the largest effect size (0.69), whereas the Asymptomatic cluster showed the smallest effect size (0.22). For cued-recall, the Irritability cluster had the largest effect size among groups (0.64), and Anxiety/Depression had the smallest effect size (0.21).Conclusions: In MCI patients, the Irritability and Apathy NPS clusters shared similar patterns of worsening in memory functioning, which could point to these NPS as risk factors of a faster cognitive decline, acting as early prognostic markers and helping in the diagnostic process.

The effects of different learning conditions on the development of collocational knowledge in a second language

<p>Previous research has shown that incidental exposure to second-language collocations in reading texts can produce gains in declarative collocational knowledge. However, there is little evidence that incidental exposure leads to the acquisition of procedural collocational knowledge. One key study that investigated these two areas was Sonbul and Schmitt (2013). They found that advanced non-native speakers gained substantial declarative knowledge of low-frequency technical collocations after three exposures in two incidental reading conditions in one treatment session; typographic enhancement of the collocations produced more correct answers than no enhancement. However, the researchers found no evidence of procedural collocational knowledge in a primed lexical decision task. Experiment 1 in this thesis was a conceptual replication and extension of Sonbul and Schmitt (2013). In a counter-balanced learning and experimental condition, 62 advanced adult ESL speakers were exposed to nine occurrences of 15 low-frequency technical collocations in 500-word texts in three sessions on two consecutive days. (input flooding). Three incidental learning treatments were implemented: reading-only (typographically unenhanced), bolding-only and bolding-plus-glossing. Collocational knowledge was assessed in two tests of declarative knowledge: a cued-recall (gapfill) test and a form-recognition (multiple-choice) test. Procedural collocational knowledge was operationalised as a priming effect in a primed lexical decision task. The results of the immediate cued-recall and form-recognition post-tests corroborate Sonbul and Schmitt’s findings: multiple encounters with the collocations produced substantial declarative collocational knowledge, and more declarative knowledge was produced through exposure to typographically-enhanced collocations (with and without glosses) than to typographically-unenhanced collocations. Procedural knowledge was found, but, unexpectedly, only in the reading-only treatment. Experiment 2 focused on non-technical lexical (verb + noun) collocations and grammatical (preposition + noun) collocations. Two incidental learning conditions were used: bolding and no-bolding. Seventy-eight intermediate-to-upper-intermediate-level adult native speakers of Chinese were exposed to six occurrences of each of 48 non-technical English collocations as they read twelve 170-word treatment texts on two consecutive days. The immediate post-test session comprised a gapfill (cued-recall) test, for measuring declarative knowledge, and a self-paced reading task, for measuring procedural knowledge. The results show an increase in declarative knowledge in both learning conditions. Bolding produced more declarative knowledge of preposition + noun collocations than no bolding; however, bolding was no more effective than no bolding for verb + noun collocations. In the self-paced reading task, the absence of bolding of verb + noun collocations led to a tendency towards the development of procedural knowledge, but this was not the case for the typographically enhanced verb + noun collocations. For preposition + noun collocations (both unbolded and bolded) no evidence of procedural knowledge was found. The findings of both experiments indicate that input flooding of collocations in incidental learning conditions can produce declarative collocational knowledge, and that typographic enhancement may lead to more declarative knowledge than lack of typographic enhancement. Repeated exposure to typographically-unenhanced collocations in reading contexts may produce procedural knowledge of collocations more quickly than exposure to typographically-enhanced collocations. These findings indicate that declarative and procedural knowledge of MWUs are dissociated in the sense that they follow different developmental paths. In a teaching context, I predict that the knowledge of collocations may be acquired incidentally through the use of texts such as graded readers which contain multiple instances of collocations.</p>

The effects of different learning conditions on the development of collocational knowledge in a second language

<p>Previous research has shown that incidental exposure to second-language collocations in reading texts can produce gains in declarative collocational knowledge. However, there is little evidence that incidental exposure leads to the acquisition of procedural collocational knowledge. One key study that investigated these two areas was Sonbul and Schmitt (2013). They found that advanced non-native speakers gained substantial declarative knowledge of low-frequency technical collocations after three exposures in two incidental reading conditions in one treatment session; typographic enhancement of the collocations produced more correct answers than no enhancement. However, the researchers found no evidence of procedural collocational knowledge in a primed lexical decision task. Experiment 1 in this thesis was a conceptual replication and extension of Sonbul and Schmitt (2013). In a counter-balanced learning and experimental condition, 62 advanced adult ESL speakers were exposed to nine occurrences of 15 low-frequency technical collocations in 500-word texts in three sessions on two consecutive days. (input flooding). Three incidental learning treatments were implemented: reading-only (typographically unenhanced), bolding-only and bolding-plus-glossing. Collocational knowledge was assessed in two tests of declarative knowledge: a cued-recall (gapfill) test and a form-recognition (multiple-choice) test. Procedural collocational knowledge was operationalised as a priming effect in a primed lexical decision task. The results of the immediate cued-recall and form-recognition post-tests corroborate Sonbul and Schmitt’s findings: multiple encounters with the collocations produced substantial declarative collocational knowledge, and more declarative knowledge was produced through exposure to typographically-enhanced collocations (with and without glosses) than to typographically-unenhanced collocations. Procedural knowledge was found, but, unexpectedly, only in the reading-only treatment. Experiment 2 focused on non-technical lexical (verb + noun) collocations and grammatical (preposition + noun) collocations. Two incidental learning conditions were used: bolding and no-bolding. Seventy-eight intermediate-to-upper-intermediate-level adult native speakers of Chinese were exposed to six occurrences of each of 48 non-technical English collocations as they read twelve 170-word treatment texts on two consecutive days. The immediate post-test session comprised a gapfill (cued-recall) test, for measuring declarative knowledge, and a self-paced reading task, for measuring procedural knowledge. The results show an increase in declarative knowledge in both learning conditions. Bolding produced more declarative knowledge of preposition + noun collocations than no bolding; however, bolding was no more effective than no bolding for verb + noun collocations. In the self-paced reading task, the absence of bolding of verb + noun collocations led to a tendency towards the development of procedural knowledge, but this was not the case for the typographically enhanced verb + noun collocations. For preposition + noun collocations (both unbolded and bolded) no evidence of procedural knowledge was found. The findings of both experiments indicate that input flooding of collocations in incidental learning conditions can produce declarative collocational knowledge, and that typographic enhancement may lead to more declarative knowledge than lack of typographic enhancement. Repeated exposure to typographically-unenhanced collocations in reading contexts may produce procedural knowledge of collocations more quickly than exposure to typographically-enhanced collocations. These findings indicate that declarative and procedural knowledge of MWUs are dissociated in the sense that they follow different developmental paths. In a teaching context, I predict that the knowledge of collocations may be acquired incidentally through the use of texts such as graded readers which contain multiple instances of collocations.</p>

The hippocampus as the switchboard between perception and memory

Adaptive memory recall requires a rapid and flexible switch from external perceptual reminders to internal mnemonic representations. However, owing to the limited temporal or spatial resolution of brain imaging modalities used in isolation, the hippocampal–cortical dynamics supporting this process remain unknown. We thus employed an object-scene cued recall paradigm across two studies, including intracranial electroencephalography (iEEG) and high-density scalp EEG. First, a sustained increase in hippocampal high gamma power (55 to 110 Hz) emerged 500 ms after cue onset and distinguished successful vs. unsuccessful recall. This increase in gamma power for successful recall was followed by a decrease in hippocampal alpha power (8 to 12 Hz). Intriguingly, the hippocampal gamma power increase marked the moment at which extrahippocampal activation patterns shifted from perceptual cue toward mnemonic target representations. In parallel, source-localized EEG alpha power revealed that the recall signal progresses from hippocampus to posterior parietal cortex and then to medial prefrontal cortex. Together, these results identify the hippocampus as the switchboard between perception and memory and elucidate the ensuing hippocampal–cortical dynamics supporting the recall process.

Long Retention Intervals Impair the Confidence-Accuracy Relationship for Eyewitness Recall

A growing body of research suggests that confidence judgements can provide a useful indicator of memory accuracy under some conditions. One factor known to affect eyewitness accuracy, yet rarely examined in the confidence-accuracy literature, is retention interval. Using calibration analyses, we investigated how retention interval affects the confidence-accuracy relationship for eyewitness recall. In total, 611 adults watched a mock crime video and completed a cued-recall test either immediately, after 1 week, or after 1 month. Long (1 month) delays led to lower memory accuracy, lower confidence judgements, and impaired the confidence-accuracy relationship compared to shorter (immediate and 1 week) delays. Long-delay participants who reported very high levels of confidence tended to be over-confident in the accuracy of their memories compared to other participants. Self-rated memory ability, however, did not predict eyewitness confidence or the confidence-accuracy relationship. We discuss the findings in relation to cue-utilization theory and a retrieval-fluency account.