Differential constraints on the working memory and reading abilities of individuals with learning difficulties and typically developing children

This study examined the factors that constrain the working memory span performance and reading ability of individuals with generalized learning difficulties. In the study, 50 individuals with learning difficulties (LD) and 50 typically developing children (TD) matched for reading age completed two working memory span tasks. Participants also completed independent measures of the processing and storage operations involved in each working memory span task and Raven's Coloured Progressive Matrices. The results showed that despite an equivalent level of working memory span, the relative importance of the constraints on working memory differed between the groups. In addition, working memory span was not closely related to word recognition or sentence comprehension performance in the LD group. These results suggest that the working memory span performance of LD and TD individuals may reflect different working memory limitations and that individuals with generalized learning difficulties may approach cognitive tasks in a qualitatively different way from that of typically developing individuals.     

The academic outcomes of working memory and metacognitive strategy training in children: A double‐blind randomized controlled trial

Working memory training has been shown to improve performance on untrained working memory tasks in typically developing children, at least when compared to non‐adaptive training; however, there is little evidence that it improves academic outcomes. The lack of transfer to academic outcomes may be because children are only learning skills and strategies in a very narrow context, which they are unable to apply to other tasks. Metacognitive strategy interventions, which promote metacognitive awareness and teach children general strategies that can be used on a variety of tasks, may be a crucial missing link in this regard. In this double‐blind randomized controlled trial, 95 typically developing children aged 9–14 years were allocated to three cognitive training programmes that were conducted daily after‐school. One group received Cogmed working memory training, another group received concurrent Cogmed and metacognitive strategy training, and the control group received adaptive visual search training, which better controls for expectancy and motivation than non‐adaptive training. Children were assessed on four working memory tasks, reading comprehension, and mathematical reasoning before, immediately after, and 3 months after training. Working memory training improved working memory and mathematical reasoning relative to the control group. The improvements in working memory were maintained 3 months later, and these were significantly greater for the group that received metacognitive strategy training, compared to working memory training alone. Working memory training is a potentially effective educational intervention when provided in addition to school; however, future research will need to investigate ways to maintain academic improvements long term and to optimize metacognitive strategy training to promote far‐transfer. A video abstract of this article can be viewed at https://youtu.be/-7MML48ZFgw     

Short-Term Memory Deficits Are Not Uniform in Down and Williams Syndromes

Neuropsychological investigation of the development of the mnesic function in mental retardation has primarily focused on evaluating short-term memory (STM). Studies have often documented a reduced verbal short-term memory span in individuals with mental retardation and with Down syndrome in particular, compared to groups of mental age-matched controls. However, recent evidence suggests that verbal short-term memory is not equally impaired in all individuals with mental retardation. Findings in children with Williams syndrome are particularly relevant in this regard. Also, data concerning STM for visual information suggest that visual-object and visual-spatial working memory may be differently compromised in people with mental retardation. In particular, individuals with Williams syndrome exhibit specific difficulties in visual-spatial but not in visual-object working memory tasks compared to typically-developing children matched for mental age. Instead, people with Down syndrome show reduced performance in both visual-spatial and visual-object tests. Taken together, these results reinforce the view that intellectual disability is not a unitary condition characterized by homogeneous slowness of cognitive development but a variety of conditions in which some cognitive functions may be more disrupted than others. The finding that the working memory deficit in individuals with Williams and Down syndrome may be qualitatively differentiated also supports the hypothesis that it is not simply a manifestation of general cognitive impairment but, rather, the expression of a specific deficit of a discrete cognitive ability.     

Validity of the Rey Visual Design Learning Test in Primary and Secondary School Children

Studies on adults have revealed a disadvantageous effect of negative emotional stimuli on executive functions (EF), and it is suggested that this effect is amplified in children. The present study’s aim was to assess how emotional facial expressions affected working memory in 9- to 12-year-olds, using a working memory task with emotional facial expressions as stimuli. Additionally, we explored how degree of internalizing and externalizing symptoms in typically developing children was related to performance on the same task. Before employing the working memory task with emotional facial expressions as stimuli, an independent sample of 9- to 12-year-olds was asked to recognize the facial expressions intended to serve as stimuli for the working memory task and to rate the facial expressions on the degree to which the emotion was expressed and for arousal to obtain a baseline for how children during this age recognize and react to facial expressions. The first study revealed that children rated the facial expressions with similar intensity and arousal across age. When employing the working memory task with facial expressions, results revealed that negatively valenced expressions impaired working memory more than neutral and positively valenced expressions. The ability to successfully complete the working memory task increased between 9 to 12 years of age. Children’s total problems were associated with poorer performance on the working memory task with facial expressions. Results on the effect of emotion on working memory are discussed in light of recent models and empirical findings on how emotional information might interact and interfere with cognitive processes such as working memory.     

The development of children’s early memory skills

A multitask battery tapping nonverbal memory and language skills was used to assess 60 children at 18, 24, and 30 months of age. Analyses focused on the degree to which language, working memory, and deliberate memory skills were linked concurrently to children’s Elicited Imitation task performance and whether the patterns of association varied across the different ages. Language ability emerged as a predictor of immediate Elicited Imitation performance by 24 months of age and predicted delayed performance at each age. In addition to the contributions of language, children’s abilities to search for and retrieve toys in the deliberate memory task were associated with their immediate Elicited Imitation performance at each age. In addition to language, working memory was positively associated with aspects of both immediate and delayed performance at all ages. The extent to which it was possible to replicate and extend previous cross-sectional work in this longitudinal study is discussed.     

Representation and working memory in early arithmetic

Working memory has been implicated in the early acquisition of arithmetic skill, but the relations among different components of working memory, performance on different types of arithmetic problems, and development have not been explored. Preschool and Grade 1 children completed measures of phonological, visual-spatial, and central executive working memory, as well as nonverbal and verbal arithmetic problems, some of which included irrelevant information. For preschool children, accuracy was higher on nonverbal problems than on verbal problems, and the best and only unique predictor of performance on the standard nonverbal problems was visual-spatial working memory. This finding is consistent with the view that most preschoolers use a mental model for arithmetic that requires visual-spatial working memory. For Grade 1 children, performance was equivalent on nonverbal and verbal problems, and phonological working memory was the best predictor of performance on standard verbal problems. For both age groups, problems with added irrelevant information were substantially more difficult than standard problems, and in some cases measures of the central executive predicted performance. Assessing performance on different components of working memory in conjunction with different types of arithmetic problems provided new insights into the developing relations between working memory and how children do arithmetic.     

工作记忆模型的第四个组成部分——情景缓冲器

工作记忆的提出迄今已有30多年的历史了,随着实验方法和技术的发展对工作记忆的研究取得了很大的突破,但在很多问题上仍存在争议,特别是在工作记忆与长时记忆、语音回路与视空间模板的联结上的解释还有许多不足.基于此,Baddeley于2000年提出了工作记忆模型的第四个组成部分--情景缓冲器(episodic buffer).情景缓冲器是一个容量有限的暂时贮存多种编码信息的装置,它受中央执行系统的控制,而中央执行系统能够通过意识觉察从存贮中提取信息,反映信息,在必要的时候能够修正信息.新的工作记忆模型更加完整,更加有解释力.     

The relationship between sleep problems and working memory in children born very preterm

In two studies, the relationship between sleep and working memory performance was investigated in children born very preterm (i.e., gestation less than 32 weeks) and the possible mechanisms underlying this relationship. In Study 1, parent-reported measures of snoring, night-time sleep quality, and daytime sleepiness were collected on 89 children born very preterm aged 6 to 7 years. The children completed a verbal working memory task, as well as measures of processing speed and verbal storage capacity. Night-time sleep quality was found to be associated with verbal working memory performance over and above the variance associated with individual differences in processing speed and storage capacity, suggesting that poor sleep may have an impact on the executive component of working memory. Snoring and daytime sleepiness were not found to be associated with working memory performance. Study 2 introduced a direct measure of executive functioning and examined whether sleep problems would differentially impact the executive functioning of children born very preterm relative to children born to term. Parent-reported sleep problems were collected on 43 children born very preterm and 48 children born to term (aged 6 to 9 years). Problematic sleep was found to adversely impact executive functioning in the very preterm group, while no effect of sleep was found in the control group. These findings implicate executive dysfunction as a possible mechanism by which problematic sleep adversely impacts upon cognition in children born very preterm, and suggest that sleep problems can increase the cognitive vulnerability already experienced by many of these children.     

Working memory, reading, and mathematical skills in children with developmental coordination disorder

The aim of the present study was investigate the relationship between working memory and reading and mathematical skills in 55 children diagnosed with developmental coordination disorder (DCD). The findings indicate a pervasive memory deficit in all memory measures. In particular, deficits observed in visuospatial short-term and working memory tasks were significantly worse than in the verbal short-term memory ones. On the basis of these deficits, the sample was divided into high and low visuospatial memory ability groups. The low visuospatial memory group performed significantly worse on the attainment measures compared to the high visuospatial memory group, even when the contribution of IQ was taken into account. When the sample was divided into high and low verbal working memory ability groups, verbal working memory skills made a unique contribution to attainment only when verbal IQ was taken into account, but not when performance IQ was statistically controlled. It is possible that the processing demands of the working memory tasks together with the active motor component reflected in the visuospatial memory tasks and performance IQ subtest both play a crucial role in learning in children with DCD.     

工作记忆训练提升幼儿流体智力表现

目前已有许多研究证据表明, 工作记忆训练能提高成人、儿童的流体智力成绩, 然而这种训练是否能够提高幼儿的流体智力表现, 更为重要的是, 如果训练确有成效, 那么这种训练效果能否长期保持？为此, 本研究选择了幼儿园4~5岁幼儿进行工作记忆训练任务, 考察工作记忆训练对流体智力的提升及保持效应。实验中设立3个组：实验组、控制1组和控制2组。实验组采用单个空间n-back的工作记忆游戏程序进行训练, 控制1组采用“水果忍者”的游戏程序进行训练, 两组进行游戏训练的时间均为14天, 每天15 min; 控制2组不进行任何训练。结果发现, 训练后实验组幼儿被试的流体智力成绩明显优于两个控制组, 在6个月后再进行测试, 这种优势仍然保持。本研究结果表明, n-back工作记忆训练可以提高幼儿的流体智力成绩, 并且这种训练效果具有持续的稳定性。     

Development of navigational working memory: Evidence from 6‐ to 10‐year‐old children

The ability to learn complex environments may require the contribution of different types of working memory. Therefore, we investigated the development of different types of working memory (navigational, reaching, and verbal) in 129 typically developing children. We aimed to determine whether navigational working memory develops at the same rate as other types of working memory and whether the gender differences reported in adults are already present during development. We found that navigational working memory is less developed than both verbal and reaching working memory and that gender predicts performance only for navigational working memory. Our results are in line with reports that children made significantly more errors in far space than adults, showing that near space representation develops before far space representation.     

Working memory updating and the development of rule-guided behavior

The transition from middle childhood into adolescence is marked by both increasing independence and also extensive change in the daily requirements of familial demands, social pressures, and academic achievement. To manage this increased complexity, children must develop the ability to use abstract rules that guide the choice of behavior across a range of circumstances. Here, we tested children through adults in a task that requires increasing levels of rule abstraction, while separately manipulating competition among alternatives in working memory. We found that age-related differences in rule-guided behavior can be explained in terms of improvement in rule abstraction, which we suggest involves a working memory updating mechanism. Furthermore, family socioeconomic status (SES) predicted change in rule-guided behavior, such that higher SES predicted better performance with development. We discuss these results within a working memory gating framework for abstract rule-guided behavior.     

A comparison of working memory profiles in children with ADHD and DCD

The main objective of present study was to investigate whether the patterns of working memory performance differ as a function of attention and motor difficulties, and whether children with ADHD and DCD could be reliably discriminated on the basis of their memory deficits. A related aim was to investigate the link between their working memory profiles and academic attainment. Fifty children with ADHD-Combined, 55 children with DCD, and an age-matched group of 50 typically developing children with average working memory were assessed on standardized measures of working memory, IQ, and academic attainment (reading, spelling, comprehension, and math). The normal controls performed significantly better than both clinical groups on all working memory tests. Specific patterns emerged in the memory profile of the clinical groups: The children with DCD had a depressed performance in all working memory tests, with particularly low scores in visuospatial memory tasks; children with ADHD performed within age-expected levels in short-term memory but had a pervasive working memory deficit that impacted both verbal and visuospatial domains. The clinical groups could reliably be discriminated on the basis of their short-term memory scores. Their learning profiles were similar. It is possible that the working memory profiles of the children with ADHD and DCD are influenced by distinct underlying cognitive mechanisms, rather than a general neurodevelopmental delay. Despite these distinctive patterns of memory performance, both clinical groups performed similarly on academic attainments, suggesting that memory may underlie learning difficulties, independent of related clinical disorders.     

Delineation of a spatial working memory profile using a non-verbal eye-tracking paradigm in young children with autism and Williams syndrome

Working memory deficits profoundly inhibit children’s ability to learn. While deficits have been identified in disorders such as autism spectrum disorder (ASD) and Williams syndrome (WS), findings are equivocal, and very little is known about the nature of these deficits early in development. A major barrier to advances in this area is the availability of tasks suitable for young children with neurodevelopmental disorders who experience difficulties with following verbal instructions or who are distressed by formal testing demands. To address these issues, a novel eye-tracking paradigm was designed based on an adaptation of the classic A not B paradigm in order to examine the early foundations of spatial working memory capabilities in 26 developmentally delayed preschool children with ASD, 18 age- and IQ-matched children with WS, and 19 age-matched typically-developing (TD) children. The results revealed evidence that foundational spatial working memory performance in ASD and WS was comparable with that of TD children. Performance was associated with intellectual ability in the ASD and TD groups, but not in the WS group. Performance was not associated with adaptive behavior in any group. These findings are discussed in the context of previous research that has been largely limited to older and substantially less developmentally delayed children with these neurodevelopmental disorders.     

Cognitive Offloading: Structuring the Environment to Improve Children's Working Memory Task Performance

Research has shown that adults can engage in cognitive offloading, whereby internal processes are offloaded onto the environment to help task performance. Here, we investigate an application of this approach with children, in particular children with poor working memory. Participants were required to remember and recall sequences of colors by placing colored blocks in the correct serial order. In one condition the blocks were arranged to facilitate cognitive offloading (i.e., grouped by color), whereas in the other condition they were arranged randomly. Across two experiments (total N = 166) the ordered condition improved task performance for children with low working memory ability. In addition, participants in Experiment 2 rated the difficulty of the two arrangements and performed a further condition in which they were given an opportunity to freely arrange the blocks before completing the task. Despite performing better in the ordered condition, children with low working memory ability did not rate the ordered arrangement as easier, nor did they choose an ordered arrangement when given the opportunity to do so. This research shows that cognitive offloading can also be a useful process in populations other than typical adults, and the implications of this work for supporting children with poor working memory are discussed.     

Working memory and fine motor skills predict early numeracy performance of children with cerebral palsy

Early numeracy is an important precursor for arithmetic performance, academic proficiency, and work success. Besides their apparent motor difficulties, children with cerebral palsy (CP) often show additional cognitive disturbances. In this study, we examine whether working memory, non-verbal intelligence, linguistic skills, counting and fine motor skills are positively related to the early numeracy performance of 6-year-old children with CP. A total of 56 children (M = 6.0, SD = 0.61, 37 boys) from Dutch special education schools participated in this cross-sectional study. Of the total group, 81% of the children have the spastic type of CP (33% unilateral and 66% bilateral), 9% have been diagnosed as having diskinetic CP, 8% have been diagnosed as having spastic and diskinetic CP and 2% have been diagnosed as having a combination of diskinetic and atactic CP. The children completed standardized tests assessing early numeracy performance, working memory, non-verbal intelligence, sentence understanding and fine motor skills. In addition, an experimental task was administered to examine their basic counting performance. Structural equation modeling showed that working memory and fine motor skills were significantly related to the early numeracy performance of the children (β = .79 and p < .001, β = .41 and p < .001, respectively). Furthermore, counting was a mediating variable between working memory and early numeracy (β = .57, p < .001). Together, these findings highlight the importance of working memory for early numeracy performance in children with CP and they warrant further research into the efficacy of intervention programs aimed at working memory training.     

Time-based prospective memory difficulties in children with ADHD and the role of time perception and working memory

Time-based prospective memory (PM) is the ability to remember to perform an intended action at a given time in the future. It is a competence that is crucial for effective performance in everyday life and may be one of the main causes of problems for individuals who have difficulty in planning and organizing their life, such as children with attention deficit/hyperactivity disorder (ADHD). This study systematically examines different aspects of time-based PM performance in a task that involves taking an action at a given future time in a group of 23 children with ADHD who were compared with a matched group of typically-developing (TD) children. The children were asked to watch a cartoon and then answer a questionnaire about its content (ongoing task). They were also asked to press a key every 2 minutes while watching the cartoon (PM task). The relationships of time perception and verbal working memory with PM performance were examined by administering appropriate tasks. The results showed that the children with ADHD were less accurate than the TD children in the PM task and exhibited less strategic time-monitoring behavior. Time perception was found to predict PM accuracy, whereas working memory was mainly involved in time-monitoring behavior, but this applied more to the TD group than to the ADHD group, suggesting that children with ADHD are less able to use their cognitive resources when meeting a PM request.     

Individual differences in sentence memory

Results from an experiment with two parts are presented in this paper. In part one, participants listened to sentences containing two, three, four, or five clauses, and were asked questions about the content of the sentences. The results of part one demonstrate that an important unit of representation in sentence memory is the clause, and not some other component of discourse structure. In part two, the same group of participants performed eight different short-term storage/working memory tasks. A composite complex span score was computed for each participant based on three working memory tasks closely based on Daneman & Carpenter's (1980) reading span task. This working memory measure was significantly correlated with the participants' performance on the sentence memory task in part one. A second working memory measure—N-back—was also significantly correlated with the participants' performance on the sentence memory task, and there was no correlation between their performance on the complex span task and the N-back task. It is therefore concluded that (i) working memory consists of a number of dissociable components; and (ii) memory for sentences taps into more than one of these working memory components. Furthermore, the high correlations of sentence memory with the complex span and the N-back tasks (neither of which are language processing tasks) suggests that memory for sentences is not simply a result of linguistic experience; rather, it is likely that an independent working memory component contributes to participants' performance on the sentence memory task.     

Investigating the childhood development of working memory using sentences: New evidence for the growth of chunk capacity

Child development is accompanied by a robust increase in immediate memory. This may be due to either an increase in the number of items (chunks) that can be maintained in working memory or an increase in the size of those chunks. We tested these hypotheses by presenting younger and older children (7 and 12 years of age) and adults with different types of lists of auditory sentences: four short sentences, eight short sentences, four long sentences, and four random word lists, each read with a sentence-like intonation. Young children accessed (recalled words from) fewer clauses than did older children or adults, but no age differences were found in the proportion of words recalled from accessed clauses. We argue that the developmental increase in memory span was due to a growing number of chunks present in working memory with little role of chunk size.     

Working memory and behavioral inhibition in children with attention-deficit/hyperactivity disorder (ADHD): an examination of varied central executive demands,construct overlap,and task impurity

The stop-signal paradigm is the premier metric of behavioral inhibition in contemporary attention-deficit/hyperactivity disorder (ADHD) research. The stop-signal paradigm’s choice-reaction time component, however, arguably places greater demands on working memory processes (e.g., controlled-focused attention) relative to alternative inhibition metrics (i.e., go/no-go (GNG) tasks), and consequently obscures conclusions about inhibition and working memory deficits in affected children. The current study, therefore, aimed to determine whether shared variance between stop-signal behavioral inhibition and working memory performance in children with ADHD reflects overlap between the working memory and inhibition constructs or insufficient specificity of the stop-signal paradigm. Fifty-five children (8–12 years) with and without ADHD were administered established phonological (PH) and visuospatial (VS) working memory measures, as well as stop-signal and GNG tasks that vary with respect to demands on controlled-focused attention. Although working memory and GNG performance each uniquely predicted children’s inattention, stop-signal task performance was not a significant predictor of unique variance in inattention, above and beyond variance associated with working memory. Collectively, these findings suggest that performance on the stop-signal task, compared to the GNG task, is confounded by greater demands associated with working memory and consequently reflects an impure estimate of the inhibition construct.