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).

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.

Age-related differences in adults' ability to follow spoken instructions.

A growing body of research illustrates that working memory capacity is a crucial limiting factor in our ability to follow spoken instructions. Despite the ubiquitous nature of instruction following throughout the lifespan, how the natural ageing process affects the ability to do so is not yet fully understood. In this study, we investigated the consequences of action at encoding and recall on the ability to follow spoken instructions. Younger (< 30 y/o) and older (> 65 y/o) adults recalled sequences of spoken action commands under presentation and recall conditions that either did or did not involve their physical performance. Both groups showed an enacted-recall advantage, with superior recall by physical performance than oral repetition. When both encoding and recall were purely verbal, older adults' recall accuracy was comparable to that of their younger counterparts. When action was involved at either encoding or recall, however, the difference in performance between the two age groups became pronounced: enactment-based encoding significantly improved younger adults' ability to follow spoken instructions; there was no such advantage for older adults. These data show that spatial-motoric representations disproportionately benefit younger adults' memory performance. We discuss the practical implications of these findings in the context of lifelong learning.

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.

Outcomes versus intentions in fairness-related decision making: School-aged children's decisions are just like those of adults.

The notion of what constitutes fairness has been assumed to change during childhood, in line with a marked shift from outcome-based to intention-based moral reasoning. However, the precise developmental profile of such a shift is still subject to debate. This study sought to determine the age at which the perceived intentions of others begin to influence fairness-related decision making in children (aged 6-8 and 9-11 years) and adolescents (aged 14 and 15 years) in the context of the mini-ultimatum game. The mini-ultimatum game has a forced-choice design, whereby a proposer needs to select one of two predetermined offers that a responder can either accept or reject. Due to these constraints, the procedure measures sensitivity to unfair intentions in addition to unfair outcomes. Participants needed to make judgments about how likely they would be to reject various offers, how fair they judged these offers to be, and the emotion they experienced when thinking about the offers. Contrary to previous published reports, we found that even 6- to 8-year-olds employed a sophisticated notion of fairness that took into account the alternatives the proposer had available. Crucially, decision making did not differ as a function of age. A further, and novel, aim was to trace the developmental origins of temporal asymmetries in judgments ab out fairness by testing the implications of adopting a past or future temporal perspective. Across all ages, we found no evidence that fairness-based decision making varies as a function of temporal location.

Time Points: A Gestural Study of the Development of Space-Time Mappings.

Human languages typically employ a variety of spatial metaphors for time (e.g., "I'm looking forward to the weekend"). The metaphorical grounding of time in space is also evident in gesture. The gestures that are performed when talking about time bolster the view that people sometimes think about regions of time as if they were locations in space. However, almost nothing is known about the development of metaphorical gestures for time, despite keen interest in the origins of space-time metaphors. In this study, we examined the gestures that English-speaking 6-to-7-year-olds, 9-to-11-year-olds, 13-to-15-year-olds, and adults produced when talking about time. Participants were asked to explain the difference between pairs of temporal adverbs (e.g., "tomorrow" versus "yesterday") and to use their hands while doing so. There was a gradual increase across age groups in the propensity to produce spatial metaphorical gestures when talking about time. However, even a substantial majority of 6-to-7-year-old children produced a spatial gesture on at least one occasion. Overall, participants produced fewer gestures in the sagittal (front-back) axis than in the lateral (left-right) axis, and this was particularly true for the youngest children and adolescents. Gestures that were incongruent with the prevailing norms of space-time mappings among English speakers (leftward and backward for past; rightward and forward for future) gradually decreased with increasing age. This was true for both the lateral and sagittal axis. This study highlights the importance of metaphoricity in children's understanding of time. It also suggests that, by 6 to 7 years of age, culturally determined representations of time have a strong influence on children's spatial metaphorical gestures.

Adult age differences in the effects of processing on storage in working memory: A meta-analysis.

Normal adult aging is known to be associated with lower performance on tasks assessing the short-term storage of information. However, whether or not there are additional age-related deficits associated with concurrent storage and processing demands within working memory remains unclear. Methodological differences across studies are considered critical factors responsible for the variability in the magnitude of the reported age effects. Here we synthesized comparisons of younger and older adults' performance on tasks measuring storage alone against those combining storage with concurrent processing of information. We also considered the influence of task-related moderator variables. Meta-analysis of effect sizes revealed a small but disproportionate effect of processing on older adults' memory performance. Moderator analysis indicated that equating single task storage performance across age groups (titration) and the nature of the stimulus material were important determinants of memory accuracy. Titration of storage task difficulty was found to lead to smaller, and nonsignificant, age-differences in dual task costs. These results were corroborated by supplementary Brinley and state-trace analyses. We discuss these findings in relation to the extant literature and current working memory theory as well as possibilities for future research to address the residual heterogeneity in effect sizes. (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).

Following instructions in a dual-task paradigm: Evidence for a temporary motor store in working memory.

Evidence from dual-task studies suggests that working memory supports the retention and implementation of verbal instructions. One key finding that is not readily accommodated by existing models of working memory is that participants are consistently more accurate at physically performing rather than verbally repeating a sequence of commands. This action advantage has no obvious source within the multi-component model of working memory and has been proposed to be driven by an as yet undetected limited-capacity store dedicated to the temporary maintenance of spatial, motoric, and temporal features of intended movements. To test this hypothesis, we sought to selectively disrupt the action advantage with concurrent motor suppression. In three dual-task experiments, young adults' immediate memory for sequences of spoken instructions was assessed by both action-based and spoken recall. In addition to classic interference tasks known to tax the phonological loop and central executive, motor suppression tasks designed to impair the encoding and retention of motoric representations were included. These required participants to produce repetitive sequences of either fine motor gestures (Experiment 1, N = 16) or more basic ones (Experiments 2, N = 16, and 3, N = 16). The benefit of action-based recall was reduced following the production of basic gestures but remained intact under all other interference conditions. These results suggest that the mnemonic advantage of enacted recall depends on a cognitive system dedicated to the temporary maintenance of motoric representations of planned action sequences.

Following instructions from working memory: Why does action at encoding and recall help?

Two experiments investigated the consequences of action at encoding and recall on the ability to follow sequences of instructions. Children ages 7-9 years recalled sequences of spoken action commands under presentation and recall conditions that either did or did not involve their physical performance. In both experiments, recall was enhanced by carrying out the instructions as they were being initially presented and also by performing them at recall. In contrast, the accuracy of instruction-following did not improve above spoken presentation alone, either when the instructions were silently read or heard by the child (Experiment 1), or when the child repeated the spoken instructions as they were presented (Experiment 2). These findings suggest that the enactment advantage at presentation does not simply reflect a general benefit of a dual exposure to instructions, and that it is not a result of their self-production at presentation. The benefits of action-based recall were reduced following enactment during presentation, suggesting that the positive effects of action at encoding and recall may have a common origin. It is proposed that the benefits of physical movement arise from the existence of a short-term motor store that maintains the temporal, spatial, and motoric features of either planned or already executed actions.

Following instructions in a virtual school: Does working memory play a role?

Accumulating evidence that working memory supports the ability to follow instructions has so far been restricted to experimental paradigms that have greatly simplified the practical demands of performing actions to instructions in everyday tasks. The aim of the present study was to investigate whether working memory is involved in maintaining information over the longer periods of time that are more typical of everyday situations that require performing instructions to command. Forty-two children 7-11 years of age completed assessments of working memory, a real-world following-instructions task employing 3-D objects, and two new computerized instruction-following tasks involving navigation around a virtual school to complete a sequence of practical spoken commands. One task involved performing actions in a single classroom, and the other, performing actions in multiple locations in a virtual school building. Verbal working memory was closely linked with all three following-instructions paradigms, but with greater association to the virtual than to the real-world tasks. These results indicate that verbal working memory plays a key role in following instructions over extended periods of activity.