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.

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).

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).

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).

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).

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).

Are small additions solved by direct retrieval from memory or automated counting procedures? A rejoinder to Chen and Campbell (2018).

Contrary to the longstanding and consensual hypothesis that adults mainly solve small single-digit additions by directly retrieving their answer from long-term memory, it has been recently argued that adults could solve small additions through fast automated counting procedures. In a recent article, Chen and Campbell (Psychonomic Bulletin & Review, 25, 739-753, 2018) reviewed the main empirical evidence on which this alternative hypothesis is based, and concluded that there is no reason to jettison the retrieval hypothesis. In the present paper, we pinpoint the fact that Chen and Campbell reached some of their conclusions by excluding some of the problems that need to be considered for a proper argumentation against the automated counting procedure theory. We also explain why, contrary to Chen and Campbell's assumption, the network interference model proposed by Campbell (Mathematical Cognition, 1, 121-164, 1995) cannot account for our data. Finally, we clarify a theoretical point of our model.

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.

On some of the main criticisms of the modal model: Reappraisal from a TBRS perspective.

The model developed by Atkinson and Shiffrin describes memory as a flow of information that enters and leaves a short-term storage and that in some cases consolidates into a long-term store. Their model has stimulated 50 years of memory research and, like every model, has also received several criticisms. It has been argued that a single short-term store in charge of both maintaining memory items and processing other cognitive tasks is not plausible. Some authors have evaluated the proposal of a rehearsal process as the unique way to transfer information into long-term memory as not being likely. Finally, the idea that information decays from the short-term store in the absence of rehearsal maintaining the memory traces has been and is still debated in the working memory literature. In this article, we reconsider these criticisms and show why they are not totally legitimate. We describe a recent working memory model, the time-based resource-sharing (TBRS) model (Barrouillet, P., & Camos, V. (2015). Working memory: Loss and reconstruction. Hove, UK: Psychology Press), that shares several theoretical assumptions with the model initially proposed by Atkinson and Shiffrin, assumptions supported by empirical findings. Consequently, the model proposed by Atkinson and Shiffrin in 1968 may be far from outdated and still provide an inspiring framework for memory study.

Choking under experimenter's presence: Impact on proactive control and practical consequences for psychological science.

Evidence accumulated for more than a century on audience effects shows that being watched by others typically impairs performance on difficult tasks. However, recent research under the label of « choking under pressure ¼ suggests that this performance impairment is, ironically, specific to the individuals who are the most qualified to succeed-those with a high working memory capacity (WMC). Here, we predicted and found that being watched by evaluative others such as the experimenter undermines proactive control on which the high-WMC individuals rely the more. These results refine our understanding of both audience and choking effects, and lead to innovative, practical recommendations for psychological science.

Is working memory storage intrinsically domain-specific?

It has recently been claimed that working memory (WM) storage is intrinsically domain-specific because the concurrent maintenance of an auditory and a visuospatial memory set did not involve any dual-task cost (Fougnie, Zughni, Godwin, & Marois, 2015). Using the same paradigm, we asked participants to concurrently maintain verbal auditory memory sets of 2, 4, or 6 letters along with visuospatial memory sets of 1, 3, or 5 dots in spatial locations. Whereas using the probe-recognition procedure used by Fougnie, Zughni, Godwin, and Marois (2015) replicated the absence of dual-task cost, a recall procedure revealed systematic interference between auditory-verbal and visuospatial WM. Increasing verbal WM load had a detrimental effect on the recall of visuospatial information, and vice versa, whether or not the task was performed under concurrent articulation. These between-domain interference effects proved to be non-negligible in magnitude when compared with within-domain effects in both the verbal (letters and digits) and visuospatial (spatial locations and movements) domains. The implication of these findings for our understanding of the structure and functioning of WM as well as the potential impact of the methods used to assess WM storage (i.e., recognition vs. recall) are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Storage and processing in working memory: Assessing dual-task performance and task prioritization across the adult lifespan.

There is a theoretical disagreement in the working memory literature, with some proposing that the storage and processing of information rely on distinct parts of the cognitive system and others who posit that they rely, to some extent, on a shared attentional capacity. This debate is mirrored in the literature on working memory and aging, where there have been mixed findings on the ability of older adults to perform simultaneous storage and processing tasks. We assess the overlap between storage and processing and how this changes with age using a procedure in which both tasks have been carefully adjusted to produce comparable levels of single-task performance across a sample (N = 164) of participants aged 18-81. By manipulating incentives to perform one task over the other, this procedure was also capable of disentangling concurrence costs (single- vs. dual-task performance) from prioritization costs (relative payoffs for storage vs. processing performance) in a theoretically meaningful manner. The study revealed a large general cost to serial letter recall performance associated with concurrent performance of an arithmetic verification processing task, a concurrence cost that increased with age. For the processing task, there was no such general concurrence cost. Rather, there was a prioritization effect in dual-task performance for both tasks, irrespective of age, in which performance levels depended on the relative emphasis assigned to memory versus processing. This prioritization effect was large, albeit with a large residual in performance. The findings place important constraints on both working memory theory and our understanding of how working memory changes across the adult lifespan. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Dual-task costs in working memory: An adversarial collaboration.

[Correction Notice: An Erratum for this article was reported in Vol 45(9) of Journal of Experimental Psychology: Learning, Memory, and Cognition (see record 2019-48991-001). In the article, the copyright attribution was incorrectly listed and should have published under the Creative Commons CC-BY license. The correct copyright is "© 2018 The Author(s)." All versions of this article have been corrected.] Theories of working memory often disagree on the relationships between processing and storage, particularly on how heavily they rely on an attention-based limited resource. Some posit separation and specialization of resources resulting in minimal interference to memory when completing an ongoing processing task, while others argue for a greater overlap in the resources involved in concurrent tasks. Here, we present four experiments that investigated the presence or absence of dual-task costs for memory and processing. The experiments were carried in an adversarial collaboration in which researchers from three opposing theories collaboratively designed a set of experiments and provided differential predictions in line with each of their models. Participants performed delayed recall of aurally and visually presented letters and an arithmetic verification task either as single tasks or with the arithmetic verification task between presentation and recall of letter sequences. Single- and dual-task conditions were completed with and without concurrent articulatory suppression. A consistent pattern of dual-task and suppression costs was observed for memory, with smaller or null effects on processing. The observed data did not fit perfectly with any one framework, with each model having partial success in predicting data patterns. Implications for each of the models are discussed, with an aim for future research to investigate whether some combination of the models and their assumptions can provide a more comprehensive interpretation of the pattern of effects observed here and in relevant previous studies associated with each theoretical framework. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Working memory consolidation: insights from studies on attention and working memory.

Working memory, the system that maintains a limited set of representations for immediate use in cognition, is a central part of human cognition. Three processes have recently been proposed to govern information storage in working memory: consolidation, refreshing, and removal. Here, we discuss in detail the theoretical construct of working memory consolidation, a process critical to the creation of a stable working memory representation. We present a brief overview of the research that indicated the need for a construct such as working memory consolidation and the subsequent research that has helped to define the parameters of the construct. We then move on to explicitly state the points of agreement as to what processes are involved in working memory consolidation.

Is memory better for objects than for separate single features? The temporal hypothesis.

Working memory, the system allowing for a simultaneous maintenance and processing of information, is typically conceived as a capacity limited system. A proposed method to transcend its standard maintenance capacity is to maintain multifeature objects, instead of isolated features. Several studies have shown that multifeature memory items are stored as objects instead of separate single features in working memory, this object-based maintenance being thought to result in an increase in the number of features that can be maintained. We present a series of 4 experiments that challenge the belief that object-based maintenance per se is at the origin of the better memory for features in case of multifeature item presentation. Instead, we propose an account based on the temporal parameters of the memory item's presentation, which explains memory performance in terms of the time available for encoding/consolidation per feature. (PsycINFO Database Record

On the sources of forgetting in working memory: The test of competing hypotheses.

Whether forgetting from working memory (WM) is only due to interference or is also caused by temporal decay is still a matter of debate. In the present study, this question was examined using complex span tasks in which each memory item was followed by a series of processing episodes, the duration and number of which were varied. It is known that recall performance in these tasks depends on the cognitive load ( CL) of concurrent processing conceived as the ratio between processing time and free time, higher CL resulting in lower spans. The decay-and-refresh hypothesis accounts for this effect by assuming that memory traces decay during processing but are refreshed during free time. This hypothesis predicts lower recall performance with longer processing episodes, but no effect of their number as long as CL remains constant. The interference-only hypothesis supposes that free time is used to alleviate the interference created by processing distractors. This hypothesis is potentially compatible with an effect of the duration of processing episodes through increased interference, but predicts a detrimental effect of their number. In three experiments, the recall pattern fitted the predictions of the decay-and-refresh hypothesis for verbal WM, but that of the interference-only hypothesis for visuospatial WM. Although the entire pattern of data is more easily accommodated by the decay-and-refresh hypothesis than by its interference-only contender, our results suggest that it is unwise to aim at identifying a unique source to a complex phenomenon like WM forgetting.

The fate of distractors in working memory: No evidence for their active removal.

Not all the information processed in working memory (WM) must be retained. Due to the strict limitations of its capacity, the mechanisms that prevent WM from being cluttered and choked by no longer relevant information are of paramount importance. The present study tested the hypothesis put forward by the SOB-CS model of an active and attention-demanding mechanism that would remove no-longer relevant items from WM. Such a mechanism has been advocated to account for the well-known fact that, in complex span tasks, processing distractors at a slower pace results in better recall of memory items. According to the SOB-CS model, slow pace would free more time for removing distractors, thus alleviating the interference they create on target items. In direct contradiction with this hypothesis, a first experiment demonstrated that distractors are not less, but more accessible at the end of complex span task trials in which they have been processed at a slow rather than a fast pace. Using the repetition priming effect occurring in a lexical decision task inserted as processing component within a complex span task, a second experiment established that distractors processed at a slower pace do not elicit weaker, but stronger repetition priming effects, indicating that they have not been removed. Along with previous findings, the present study not only shows that there is no trace of distractor removal in the long term, in the short term, nor immediately after processing, but demonstrates that memory traces of distractors are stronger in situations assumed to involve a more complete removal by the SOB-CS model. These empirical evidence suggests that distractors are not actively removed from working memory after having been processed.

Examining distinct working memory processes in children and adolescents using fMRI: Results and validation of a modified Brown-Peterson paradigm.

Verbal working memory (WM) comprises different processes (encoding, maintenance, retrieval) that are often compromised in brain diseases, but their neural correlates have not yet been examined in childhood and adolescence. To probe WM processes and associated neural correlates in developmental samples, and obtain comparable effects across different ages and populations, we designed an adapted Brown-Peterson task (verbal encoding and retrieval combined with verbal and visual concurrent tasks during maintenance) to implement during functional magnetic resonance imaging (fMRI). In a sample of typically developing children and adolescents (n = 16), aged 8 to 16 years, our paradigm successfully identified distinct patterns of activation for encoding, maintenance, and retrieval. While encoding activated perceptual systems in posterior and ventral visual regions, retrieval activated fronto-parietal regions associated with executive control and attention. We found a different impact of verbal versus visual concurrent processing during WM maintenance: at retrieval, the former condition evoked greater activations in visual cortex, as opposed to selective involvement of language-related areas in left temporal cortex in the latter condition. These results are in accord with WM models, suggesting greater competition for processing resources when retrieval follows within-domain compared with cross-domain interference. This pattern was found regardless of age. Our study provides a novel paradigm to investigate distinct WM brain systems with reliable results across a wide age range in developmental populations, and suitable for participants with different WM capacities.

Consolidation and restoration of memory traces in working memory.

Consolidation is the process through which ephemeral sensory traces are transformed into more stable short-term memory traces. It has been shown that consolidation plays a crucial role in working memory (WM) performance, by strengthening memory traces that then better resist interference and decay. In a recent study, Bayliss, Bogdanovs, and Jarrold (Journal of Memory and Language, 81, 34-50, 2015) argued that this process is separate from the processes known to restore WM traces after degradation, such as attentional refreshing and verbal rehearsal. In the present study, we investigated the relationship between the two types of processes in the context of WM span tasks. Participants were presented with series of letters for serial recall, each letter being followed by four digits for parity judgment. Consolidation opportunity was manipulated by varying the delay between each letter and the first digit to be processed, while opportunities for restoration were manipulated by varying the pace at which the parity task had to be performed (i.e., its cognitive load, or CL). Increasing the time available for either consolidation or restoration resulted in higher WM spans, with some substitutability between the two processes. Accordingly, when consolidation time was added to restoration time in the calculation of CL, the new resulting index, called extended CL, proved a very good predictor of recall performance, a finding also observed when verbal rehearsal was prevented by articulatory suppression. This substitutability between consolidation and restoration suggests that both processes may rely on the same mechanisms.