Quantifying resource sharing in working memory.

Several models of working memory (WM), the cognitive system devoted to the temporary maintenance of a small amount of information in view of its treatment, assume that these two functions of storage and processing share a common and limited resource. However, the predictions issued from these models concerning this resource-sharing remain usually qualitative, and at which precise extent these functions are affected by their concurrent implementation remains undecided. The aim of the present study was to quantify this resource sharing by expressing storage and processing performance during a complex span task in terms of the proportion of the highest level of performance each participant was able to reach (i.e., their span) in each component when performed in isolation. Two experiments demonstrated that, despite substantial dual-task decrements, participants managed to preserve half or more of their best performance in both components, testifying for a remarkable robustness of the human cognitive system. The implications of these results for the main WM models are discussed.

The visual familiarity effect on attentional working memory maintenance.

Attentional refreshing has been described as an attention-based, domain-general maintenance mechanism in working memory. It is thought to operate via focusing executive attention on information held in working memory, protecting it from temporal decay and interference. Although attentional refreshing has attracted a lot of research, its functioning is still debated. At least one conception of refreshing supposes that it relies on semantic long-term memory representations to reconstruct working memory traces. Although investigations in the verbal domain found evidence against this hypothesis, a different pattern could emerge in visuospatial working memory in which absence of refreshing evidence has been observed for stimuli with minimal associated long-term knowledge. In a series of four experiments, the current study investigated the hypothesis of an involvement of semantic long-term representations in the functioning of attentional refreshing in the visuospatial domain. Both cognitive and memory load effects have been proposed as indexes of attentional refreshing. Therefore, we investigated the interaction between the effects of visual familiarity (a long-term memory effect) and cognitive load on recall performance (Experiments 1A and 1B), as well as the interaction between the effects of visual familiarity and memory load on the response times in a concurrent processing task (Experiments 2A and 2B). Results were consistent across experiments and go against the hypothesis of the involvement of semantic long-term memory in the functioning of attentional refreshing in visuospatial working memory. As such, this study corroborates the results found in the verbal domain. Implications for attentional refreshing and working memory are discussed.

Time sharing in working memory processing.

Although working memory (WM) is usually defined as a cognitive system coordinating processing and storage in the short term, in most WM models, memory aspects have been developed more fully than processing systems, and many studies of WM tasks have tended to focus on memory performance. The present study investigated WM functioning without focusing exclusively on short-term memory performance by presenting participants with an n-back task on letters, n varying from 0 to 2, each letter being followed by a tone discrimination task involving from one to three tones. Predictions regarding the reciprocal effects of these tasks on each other were motivated by the time-based resource-sharing (TBRS) theoretical framework for WM that assumes the temporal sharing of attention between processing and memory. Although, as predicted, increasing the n value had a detrimental effect on tone discrimination in terms of accuracy and response times, and increasing the number of tones disrupted speed and accuracy on n-back performance, the overall pattern of results did not perfectly fit the TBRS predictions. Nonetheless, the main alternative models of WM do not seem to offer a complete account. The present findings point toward the need to use a larger range of tasks and situations in designing and testing models of WM. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Can children and adolescents with ADHD use attention to maintain verbal information in working memory?

Children and adolescents with attentional-deficit/hyperactivity disorder (ADHD) present deficits in working memory (WM), but accounts for this phenomenon are still lacking. In this study, we used two variations of a complex-span task to test whether a specific WM mechanism, attentional refreshing, causes these deficits. Attentional refreshing is a maintenance strategy based on the sequential switch of attention between maintaining and processing information in WM. Its use is evidenced by a decrease in recall performance proportional to the distraction of attention away from the memoranda. In this study, we designed two experiments requiring children and adolescents with ADHD symptoms to maintain sequences of letters for subsequent recall, while performing a distracting task. In Experiment 1, the distracting task consisted of reading digits aloud. In Experiment 2, it consisted in making spatial judgements. The pace of the distracting tasks was varied to manipulate the level of attentional distraction. We observed that recall in ADHD participants was higher in the distracting conditions that give attention more opportunity to refresh letters. Moreover, ADHD participants had a similar recall performance to their age-matched typically developing peers. This study shows first evidence that individuals with ADHD can use attention to maintain verbal information in WM and calls for more research to understand their WM development.

Is the Other-Race Effect in Working Memory Due to Attentional Refreshing?

The other-race effect is the observation that faces from another ethnicity induce worst recall performance than faces from one's own ethnicity. This effect has been defined as a type of familiarity effect, with more familiar faces better recalled than less familiar faces. In this study, we tested the hypothesis that a working memory maintenance mechanism called attentional refreshing mediates the other-race effect and that faces from one's own ethnicity are refreshed more efficiently than faces from other ethnicities. In two experiments, face ethnicity was orthogonally manipulated with cognitive load of a concurrent processing task in a complex-span paradigm (Exp. 1) and with the memory load in a Brown-Peterson paradigm (Exp. 2). Both cognitive and memory load effects are indices of the functioning of attentional refreshing. Testing Caucasian young adults, Caucasian and East-Asian faces were contrasted. Results from both experiments were congruent and against our initial hypothesis. The other-race effect in working memory does not appear to be supported by attentional refreshing. Furthermore, the results are congruent with the idea that faces as a whole are not maintained in working memory via attentional refreshing.

Sleep as a protective factor of children's executive functions: A study during COVID-19 confinement.

Confinements due to the COVID-19 outbreak affected sleep and mental health of adults, adolescents and children. Already preschool children experienced acutely worsened sleep, yet the possible resulting effects on executive functions remain unexplored. Longitudinally, sleep quality predicts later behavioral-cognitive outcomes. Accordingly, we propose children's sleep behavior as essential for healthy cognitive development. By using the COVID-19 confinement as an observational-experimental intervention, we tested whether worsened children's sleep affects executive functions outcomes 6 months downstream. We hypothesized that acutely increased night awakenings and sleep latency relate to reduced later executive functions. With an online survey during the acute confinement phase we analyzed sleep behavior in 45 children (36-72 months). A first survey referred to the (retrospective) time before and (acute) situation during confinement, and a follow-up survey assessed executive functions 6 months later (6 months retrospectively). Indeed, acutely increased nighttime awakenings related to reduced inhibition at FOLLOW-UP. Associations were specific to the confinement-induced sleep-change and not the sleep behavior before confinement. These findings highlight that specifically acute changes of children's nighttime sleep during sensitive periods are associated with behavioral outcome consequences. This aligns with observations in animals that inducing poor sleep during developmental periods affects later brain function.

How does Working Memory Promote Traces in Episodic Memory?

A longstanding research question in cognitive psychology concerns how the underlying mechanisms of working memory impact long-term episodic memory. In this series of six experiments, we manipulated three different factors within a complex span task that interleaves memoranda and distractors to investigate the contribution of these factors to the creation of episodic traces: (1) the cognitive load of processing the distractors, (2) the number of distractors, and (3) the free time following the distractors. All three factors have been identified in the prior literature as important to maintenance in working memory and, consequently, later retrieval from episodic memory. Thus, it is important to understand their unique and joint effects to the long-term durability of memory traces. Across six experiments, delayed recall (i.e., episodic memory) of the items studied during the complex span tasks (i.e., working memory) was best accounted for by accumulated free time, whereas the effects of cognitive load and number of distractors were inconsistent or negligible. These results conflict with prior work suggesting that cognitive load and the number of distractors impact episodic memory. However, the current results replicate and extend those suggesting that time spent processing items in working memory promotes the creation of episodic memory traces.

Strategic adaptation to dual-task in verbal working memory: Potential routes for theory integration.

How working memory supports dual-task performance is the focus of a long-standing debate. Most previous research on this topic has focused on participant performance data. In three experiments, we investigated whether changes in participant-reported strategies across single- and dual-task conditions might help resolve this debate by offering new insights that lead to fruitful integration of theories rather than perpetuating debate by attempting to identify which theory best fits the data. Results indicated that articulatory suppression was associated with reduced reports of the use of rehearsal and clustering strategies but to an increase of the reported use of a visual strategy. Elaboration and clustering strategies were reported less for memory under dual task compared with single task. Under both dual task and articulatory suppression, more participants reported attempting to remember fewer memory items than were presented (memory reduction strategy). For arithmetic verification, articulatory suppression and dual task resulted in a reduction in reports of a counting strategy and an increase in reports of a retrieval strategy for arithmetic knowledge. It is argued that experimenters should not assume that participants perform the same task in the same way under different experimental conditions and that carefulty investigation of how participants change their strategies in response to changes in experimental conditions has considerable potential for resolving theoretical challenges. It is argued further that this approach points toward the value of attempting to integrate rather than proliferate theories of working memory. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Children's gist-based false memory in working memory tasks.

False memories are well established episodic memory phenomena. Recent research in young adults has shown that semantically related associates can be falsely remembered as studied items in working memory (WM) tasks for lists of only a few items when a short 4-second interval was given between study and test. The present study reported two experiments yielding similar effects in 4- (n = 32 and 33, 18 and 14 females, respectively) and 8-year-old children (n = 33 and 34, respectively, 19 females in both). Short lists of semantically related items specifically tailored for young children were retained over a brief interval. Whether or not the interval was filled with a concurrent task that impeded or not WM maintenance, younger children were as prone to falsely recognize related distractors as their older counterparts in an immediate recognition test, and also in a delayed test. In addition, using the conjoint recognition model of the fuzzy-trace theory, we demonstrated that the retrieval of gist traces of the list themes was responsible for the occurrence of short-term false memories in 4- and 8-year-old children. Gist memory also underpinned the occurrence of false recognition in the delayed test. These findings suggest that young children are as likely to make gist-based false memories as older children in working memory tasks. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Attentional Orienting in Working Memory in Children with ADHD.

Children with attentional-deficit/hyperactivity disorder (ADHD) have impairments in working memory (WM) functioning. Impaired orienting of visual attention during encoding and/or maintenance is hypothesized as the cause of poor performance in visuospatial WM in 10-to-16-year-olds. We used a color-recognition task with valid location cues before encoding (pre-cues) and during maintenance (retro-cues). If ADHD children have an orienting deficit during these processing stages, they should not benefit from the cues. We observed strong pre- and retro-cueing benefits both for ADHD and typically developing controls, with no differences between the groups. This strengthens findings showing that ADHD is not characterized by deficits in orienting attention and provides evidence of retro-cue benefits in this population.

Role of attention in the associative relatedness effect in verbal working memory: Behavioral and chronometric perspectives.

Long-term semantic memory (LTM) is known for affecting recall during working memory (WM) tasks. However, the way LTM intervenes in WM remains unknown. Moreover, the available findings are incongruent concerning how attention modulates the impact of LTM on WM. To examine this issue, the involvement of LTM representations in a complex span task was manipulated through variations of the associative relatedness of memory items, while the attentional demand of the concurrent task was varied. Children and young adults were also compared, because children are less efficient in using refreshing for maintenance than adults. Despite the impact of the three main factors on recall performance, which was better for related than unrelated words, with the low rather than the high demanding concurrent task and for adults than children, there was no interaction between associative relatedness and attentional demand, neither in children nor in adults. We replicated these results in a second experiment with a more attention-demanding concurrent task. Moreover, analyses of recall latency showed that adults were faster than children at recalling words and both age groups were faster for related (vs. unrelated) words, but there was no effect of the concurrent attentional demand on recall latency and no interaction. Finally, errors were mostly omissions and transpositions, both more prevalent under high concurrent attentional demand. The present findings suggest that the availability of attention does not modulate the effect of LTM on WM. We discuss how WM models can account for this finding and how LTM can act on WM functioning. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Do goal cue and motor activity impact preschoolers' working memory?

Preschoolers are well known for their poor working memory (WM) performance. This could result from goal neglect, which would hamper the setting of maintenance strategies. Previous studies have shown that preschoolers' WM performance can be improved in game-like tasks, because they provide cues to support goal maintenance. However, in these studies, it was unclear what features of the task (either the main toy or the motor activity required by the game) provide efficient cues. The aim of the present study was to disentangle the two features to examine cue effects in 5- to 7-year-old children. No improvement of WM performance was observed when the toy was a potential goal cue, whereas the motor activity had a detrimental effect in all age groups. The latter effect could result from a distraction of attention from attention-based maintenance activities. Hence, preschoolers' poor WM performance would not be fundamentally due to goal neglect.

Play First Before Doing Your Exercise: Does Acting in a Game-Like Task Improve 5-Year-Olds' Working Memory Performance?

It has been shown that acting in a game-like task improves preschoolers' working memory when tested in a reconstruction task. The game context and the motor activity during the game would provide goal cues bringing support to the memory processes. The aim of the present study was to test this hypothesis by examining preschoolers' working memory performance in a game-like task compared to an exercise-like task, which offers less goal cues. In the present study, 5-year-olds had to maintain a series of fruits and vegetables while acting in a game-like task or remaining static during the same task presented in a school-exercise context (within-subject factor). Memory performance was tested either through oral recall or reconstruction of the series of memory items (between-subject factor). Despite the fact that memory performance did not differ between the two conditions (game vs. exercise) whatever the type of memory tests, performance was worst in the game-like than in the exercise condition when the exercise was presented first. No difference emerged between conditions when the game condition was performed first. This result suggests that preschoolers were able to take advantage of acting in the game-like condition to integrate some task requirements, which were beneficial for performing the exercise condition.

Exploring the influence of temporal factors on age differences in working memory dual task costs.

Working memory is defined by many as the system that allows us to simultaneously store information over brief time periods while engaging in other information processing activities. In a previous study (Rhodes, Jaroslawska et al. (2019) Journal of Experimental Psychology: General, 148, 1204-1227.) we found that retention of serially presented letters was disrupted by the introduction of an arithmetic processing task during a 10 second delay period. Importantly, the magnitude of this dual task disruption increased with age from 18 to 81. The demands of each task were adjusted prior to dual task so that age differences did not reflect baseline differences in single task performance. Motivated by these findings, theories of working memory, and additional analyses of processing reaction times from this previous experiment, we report two experiments, using the same tasks and adjustment procedure, attempting to modulate the magnitude of age differences in dual task effects via manipulations focused on time for encoding to-be-remembered material. Providing a delay prior to processing activities, to facilitate switching between the two tasks, did not modulate age differences. Neither did separating the to-be-remembered material temporally, to allow for the creation of more distinct representations. These findings provide two replications of our initial finding and suggest that age differences in working memory dual tasking are not due to limitations in the speed of encoding. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Severe effects of the COVID-19 confinement on young children's sleep: A longitudinal study identifying risk and protective factors.

The COVID-19 confinement has dramatically altered daily routines, causing decreased sleep quality in adults. This necessitates careful observation, as sleep plays a crucial role in brain maturation and poor sleep increases the risk of psychopathology, particularly in the young population. Through an online survey with one baseline (April 2020) and two follow-up assessments (May and June 2020), we examined the effect of confinement on sleep quality in 452 babies (0-35 months) and 412 preschool children (36-71 months) from several, mainly European, countries. An acute decrease in sleep quality was found in both groups of children. However, at follow-up assessments, this effect rebounded to the level reported for the period before the confinement. Importantly, caregiver's stress level was identified as a substantial risk factor determining lower sleep quality in both groups of children across assessments. Protective factors conserving children's sleep quality included caregiver's engagement in mindfulness techniques or childcare, and the presence of siblings and pets. In the near future, we may repeatedly experience the circumstances of abruptly enforced confinement. Our findings reveal promising pathways of action to protect young children's sleep, with which to essentially mitigate the long-term consequences of the pandemic on brain development and mental health.

What affects the magnitude of age-related dual-task costs in working memory? The role of stimulus domain and access to semantic representations.

Although there is evidence that the effect of including a concurrent processing demand on the storage of information in working memory is disproportionately larger for older than younger adults, not all studies show this age-related impairment, and the critical factors responsible for any such impairment remain elusive. Here we assess whether domain overlap between storage and processing activities, and access to semantic representations, are important determinants of performance in a sample of younger and older adults (N = 119). We developed four versions of a processing task by manipulating the type of stimuli involved (either verbal or non-verbal) and the decision that participants had to make about the stimuli presented on the screen. Participants either had to perform a spatial judgement, in deciding whether the verbal or non-verbal item was presented above or below the centre of the screen, or a semantic judgement, in deciding whether the stimulus refers to something living or not living. The memory task was serial-ordered recall of visually presented letters. The study revealed a large increase in age-related memory differences when concurrent processing was required. These differences were smaller when storage and processing activities both used verbal materials. Dual-task effects on processing were also disproportionate for older adults. Age differences in processing performance appeared larger for tasks requiring spatial decisions rather than semantic decisions. We discuss these findings in relation to three competing frameworks of working memory and the extant literature on cognitive ageing.

Is the cognitive system much more robust than anticipated? Dual-task costs and residuals in working memory.

Several working memory (WM) theories assume a resource sharing between the maintenance of information and its processing, whereas other theories suppose that these 2 functions of WM rely on different pools of resources. Studies that addressed this question by examining whether dual-task costs occur in tasks combining processing and storage have led to mixed results. Whereas some of them reported symmetric dual-task costs, others found no or negligible effects, while still others found a reduction in performance in memory but not in processing. In the present experiment, we tested whether these discrepancies in results might be due to participants strategically prioritizing one component of the task over the other. Thus, we asked participants to perform at their maximum level (i.e. span level) in one component of the dual-task and assessed performance on the other. In line with resource-sharing views, results indicated that performing at span on 1 task strongly degraded performance on the other, with symmetric costs. However, important residuals in both processing and storage suggested an unexpected resilience of the cognitive system that any resource-sharing theory must take into account. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Simple spans underestimate verbal working memory capacity.

Verbal working memory (WM) has been assumed to involve 2 different systems of maintenance, a phonological loop and a central attentional system. Though the capacity estimate for letters of each of these systems is about 4, the maximum number of letters that individuals are able to immediately recall, a measure known as simple span, is not about 8 but 6. We tested the hypothesis that, unaware of the dual structure of their verbal WM, individuals underuse it by trying to verbally rehearse too many items. In order to maximize the use of verbal WM, we designed a new procedure called the maxispan procedure. When performing an immediate serial recall task, participants were invited to cumulatively rehearse a limited number of letters, and to keep rehearsing these letters until the end of the presentation of the list in such a way that the following letters can no longer enter the phonological loop and must be stored in the attentional system. As we expected, in 3 successive experiments, the maxispan procedure resulted in a dramatic increase in spans compared with the traditional simple span procedure, with spans approaching 8 when the to-be-rehearsed letters were presented auditorily and the following letters visually. These results indicate that simple spans, which have been used for more than a century in intelligence tests and are assumed to measure the capacity of short-term memory (STM), actually reflect the complex interplay between different structures and cognitive processes. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

How Do Scientific Views Change? Notes From an Extended Adversarial Collaboration.

There are few examples of an extended adversarial collaboration, in which investigators committed to different theoretical views collaborate to test opposing predictions. Whereas previous adversarial collaborations have produced single research articles, here, we share our experience in programmatic, extended adversarial collaboration involving three laboratories in different countries with different theoretical views regarding working memory, the limited information retained in mind, serving ongoing thought and action. We have focused on short-term memory retention of items (letters) during a distracting task (arithmetic), and effects of aging on these tasks. Over several years, we have conducted and published joint research with preregistered predictions, methods, and analysis plans, with replication of each study across two laboratories concurrently. We argue that, although an adversarial collaboration will not usually induce senior researchers to abandon favored theoretical views and adopt opposing views, it will necessitate varieties of their views that are more similar to one another, in that they must account for a growing, common corpus of evidence. This approach promotes understanding of others' views and presents to the field research findings accepted as valid by researchers with opposing interpretations. We illustrate this process with our own research experiences and make recommendations applicable to diverse scientific areas.

Age-Related Changes in Verbal Working Memory Strategies.

Background/Study context: Maintenance in verbal working memory is thought to rely on two main systems: a phonological and a semantic system. The three objectives of the present study were to clarify how these systems are organized and interact, to examine whether their involvement in maintenance changes with aging, and to identify which underlying mechanism accounts for both age-related changes in the available set of mechanisms and immediate recall.Methods: To address these issues, we examined age-related changes in strategic aspects of maintenance of information in working memory. We collected trial-by-trial verbal reports of which strategy young and older adults used while accomplishing a verbal complex span task. In addition, individuals' speed of articulation was collected.Results: Results support the existence of separable systems (i.e., phonological and semantic systems) that participants combine to cope with increasing memory loads. We also found age-related differences (e.g., older individuals used more strategies than young individuals and used available strategies unequally often) and invariance (e.g., both age groups used strategies based on phonological and semantic processing) in strategic aspects of working memory maintenance. Importantly, articulation speed accounted for effects of both memory load and age on strategy distributions as well as for age-related differences in immediate recall.Conclusion: Our findings suggest that young and older adults' use of common and different sets of maintenance mechanisms stems for the constraints of the phonological loop in working memory, especially the speed of articulation, which slowed down with aging.