Academic outcomes 2 years after working memory training for children with low working memory: a randomized clinical trial

IMPORTANCE: Working memory training may help children with attention and learning difficulties, but robust evidence from population-level randomized controlled clinical trials is lacking.

OBJECTIVE: To test whether a computerized adaptive working memory intervention program improves long-term academic outcomes of children 6 to 7 years of age with low working memory compared with usual classroom teaching.

DESIGN, SETTING, AND PARTICIPANTS: Population-based randomized controlled clinical trial of first graders from 44 schools in Melbourne, Australia, who underwent a verbal and visuospatial working memory screening. Children were classified as having low working memory if their scores were below the 15th percentile on either the Backward Digit Recall or Mister X subtest from the Automated Working Memory Assessment, or if their scores were below the 25th percentile on both. These children were randomly assigned by an independent statistician to either an intervention or a control arm using a concealed computerized random number sequence. Researchers were blinded to group assignment at time of screening. We conducted our trial from March 1, 2012, to February 1, 2015; our final analysis was on October 30, 2015. We used intention-to-treat analyses.

INTERVENTION: Cogmed working memory training, comprising 20 to 25 training sessions of 45 minutes' duration at school.

MAIN OUTCOMES AND MEASURES: Directly assessed (at 12 and 24 months) academic outcomes (reading, math, and spelling scores as primary outcomes) and working memory (also assessed at 6 months); parent-, teacher-, and child-reported behavioral and social-emotional functioning and quality of life; and intervention costs.

RESULTS: Of 1723 children screened (mean [SD] age, 6.9 [0.4] years), 226 were randomized to each arm (452 total), with 90% retention at 1 year and 88% retention at 2 years; 90.3% of children in the intervention arm completed at least 20 sessions. Of the 4 short-term and working memory outcomes, 1 outcome (visuospatial short-term memory) benefited the children at 6 months (effect size, 0.43 [95% CI, 0.25-0.62]) and 12 months (effect size, 0.49 [95% CI, 0.28-0.70]), but not at 24 months. There were no benefits to any other outcomes; in fact, the math scores of the children in the intervention arm were worse at 2 years (mean difference, -3.0 [95% CI, -5.4 to -0.7]; P = .01). Intervention costs were A$1035 per child.

CONCLUSIONS AND RELEVANCE: Working memory screening of children 6 to 7 years of age is feasible, and an adaptive working memory training program may temporarily improve visuospatial short-term memory. Given the loss of classroom time, cost, and lack of lasting benefit, we cannot recommend population-based delivery of Cogmed within a screening paradigm.

Can improving working memory prevent academic difficulties? a school based randomised controlled trial

Background: Low academic achievement is common and is associated with adverse outcomes such as grade repetition, behavioural disorders and unemployment. The ability to accurately identify these children and intervene before they experience academic failure would be a major advance over the current ‘wait to fail’ model. Recent research suggests that a possible modifiable factor for low academic achievement is working memory, the ability to temporarily store and manipulate information in a ‘mental workspace’. Children with working memory difficulties are at high risk of academic failure. It has recently been demonstrated that working memory can be improved with adaptive training tasks that encourage improvements in working memory capacity. Our trial will determine whether the intervention is efficacious as a selective prevention strategy for young children at risk of academic difficulties and is cost-effective.

Methods/Design: This randomised controlled trial aims to recruit 440 children with low working memory after a school-based screening of 2880 children in Grade one. We will approach caregivers of all children from 48 participating primary schools in metropolitan Melbourne for consent. Children with low working memory will be randomised to usual care or the intervention. The intervention will consist of 25 computerised working memory training sessions, which take approximately 35 minutes each to complete. Follow-up of children will be conducted at 6, 12 and 24 months post-randomisation through child face-to-face assessment, parent and teacher surveys and data from government authorities. The primary outcome is academic achievement at 12 and 24 months, and other outcomes include child behaviour, attention, health-related quality of life, working memory, and health and educational service
utilisation.

Discussion: A successful start to formal learning in school sets the stage for future academic, psychological and economic well-being. If this preventive intervention can be shown to be efficacious, then we will have the potential to prevent academic underachievement in large numbers of at-risk children, to offer a ready-to-use intervention to the Australian school system and to build international research partnerships along the health education interface, in order to carry our further studies of effectiveness and generalisability.

Multitasking, working memory and remembering intentions

Multitasking refers to the performance of a range of tasks that have to be completed within a limited time period. it differs from dual task paradigms in that tasks are performed not in parallel, but by interleaving, switching from one to the other. it differs also from task switching paradigms in that the time scale is very much longer, multiple different tasks are involved, and most tasks have a clear end point. Multitasking has been studied extensively with particular sets of experts such as in aviation and in the military, and impairments of multitasking performance have been studied in patients with frontal lobe lesions. Much less is known as to how multitasking is achieved in healthy adults who have not had specific training in the necessary skills. This paper will provide a brief review of research on everyday multitasking, and summarise the results of some recent experiments on simulated everyday tasks chosen to require advance and on-line planning, retrospective memory, prospective memory, and visual, spatial and verbal short-term memory.

Relationship between verbal working memory and the SCAN-C in children with specific language impairment

Purpose: An ongoing concern with the evaluation of auditory processing disorders is the extent that assessment instruments are influenced by higher order cognitive functions. This study examined the relationship between verbal working memory and performance on the Test for Auditory Processing Disorders in Children--Revised (SCAN-C; Keith, 2000b) in children with specific language impairment (SLI) and typically developing (TD) children.

Method: Sixteen children with SLI and 16 TD children ages 8/4 to 11 years participated in the study. The children were presented with the SCAN-C and tests measuring verbal working memory.

Results: Initial comparisons revealed that the SLI group obtained significantly lower scores than the TD group on the SCAN-C. However, after controlling for verbal working memory, significant differences between the 2 groups were no longer observed. Correlational analyses revealed that the composite score from the SCAN-C was related to all tests assessing verbal working memory.

Conclusions: Performance on the SCAN-C may be related to working memory functioning. As a consequence, it is unclear whether difficulty on this task should be viewed as a problem with auditory processing or a problem with verbal working memory.

Malondialdehyde plasma concentration correlates with declarative and working memory in patients with recurrent depressive disorder

Oxidative stress has been implicated in the cognitive decline, especially in memory impairment. The purpose of this study was to determine the concentration of malondialdehyde (MDA) in patients with recurrent depressive disorders (rDD) and to define relationship between plasma levels of MDA and the cognitive performance. The study comprised 46 patients meeting criteria for rDD. Cognitive function assessment was based on: The Trail Making Test , The Stroop Test, Verbal Fluency Test and Auditory-Verbal Learning Test. The severity of depression symptoms was assessed using the Hamilton Depression Rating Scale (HDRS). Statistically significant differences were found in the intensity of depression symptoms, measured by the HDRS on therapy onset versus the examination results after 8 weeks of treatment (P < 0.001). Considering the 8-week pharmacotherapy period, rDD patients presented better outcomes in cognitive function tests. There was no statistically significant correlation between plasma MDA levels, and the age, disease duration, number of previous depressive episodes and the results in HDRS applied on admission and on discharge. Elevated levels of MDA adversely affected the efficiency of visual-spatial and auditory-verbal working memory, short-term declarative memory and the delayed recall declarative memory. 1. Higher concentration of plasma MDA in rDD patients is associated with the severity of depressive symptoms, both at the beginning of antidepressants pharmacotherapy, and after 8 weeks of its duration. 2. Elevated levels of plasma MDA are related to the impairment of visual-spatial and auditory-verbal working memory and short-term and delayed declarative memory.

The impact of working memory load on task execution and online plan adjustment during multitasking in a virtual environment

Three experiments investigated the impact of working memory load on online plan adjustment during a test of multitasking in young, nonexpert, adult participants. Multitasking was assessed using the Edinburgh Virtual Errands Test (EVET). Participants were asked to memorize either good or poor plans for performing multiple errands and were assessed both on task completion and on the extent to which they modified their plans during EVET performance. EVET was performed twice, with and without a secondary task loading a component of working memory. In Experiment 1, articulatory suppression was used to load the phonological loop. In Experiment 2, oral random generation was used to load executive functions. In Experiment 3, spatial working memory was loaded with an auditory spatial localization task. EVET performance for both good- and poor-planning groups was disrupted by random generation and sound localization, but not by articulatory suppression. Additionally, people given a poor plan were able to overcome this initial disadvantage by modifying their plans online. It was concluded that, in addition to executive functions, multiple errands performance draws heavily on spatial, but not verbal, working memory resources but can be successfully completed on the basis of modifying plans online, despite a secondary task load.

Age-related changes to the neural correlates of working memory which emerge after midlife

Previous research has indicated that the neural processes which underlie working memory change with age. Both age-related increases and decreases to cortical activity have been reported. This study investigated which stages of working memory are most vulnerable to age-related changes after midlife. To do this we examined age-differences in the 13 Hz steady state visually evoked potential (SSVEP) associated with a spatial working memory delayed response task. Participants were 130 healthy adults separated into a midlife (40-60 years) and an older group (61-82 years). Relative to the midlife group, older adults demonstrated greater bilateral frontal activity during encoding and this pattern of activity was related to better working memory performance. In contrast, evidence of age-related under activation was identified over left frontal regions during retrieval. Findings from this study suggest that after midlife, under-activation of frontal regions during retrieval contributes to age-related decline in working memory performance. © 2014 Macpherson, White, Ellis, Stough, Camfield, Silberstein and Pipingas.

Verbal declarative memory impairments in specific language impairment are related to working memory deficits

This study examined verbal declarative memory functioning in SLI and its relationship to working memory. Encoding, recall, and recognition of verbal information was examined in children with SLI who had below average working memory (SLILow WM), children with SLI who had average working memory (SLIAvg. WM) and, a group of non-language impaired children with average working memory (TDAvg. WM). The SLILow WM group was significantly worse than both the SLIAvg. WM and TDAvg. WM groups at encoding verbal information and at retrieving verbal information following a delay. In contrast, the SLIAvg. WM group showed no verbal declarative memory deficits. The study demonstrates that verbal declarative memory deficits in SLI only occur when verbal working memory is impaired. Thus SLI declarative memory is largely intact and deficits are likely to be related to working memory impairments.

Schooling duration rather than chronological age predicts working memory between 6 and 7 years: memory maestros study

OBJECTIVE: Low working memory (WM) is strongly linked with poor academic outcomes. WM capacity increases across childhood but how exposure to school is associated with WM development is not known. We aimed to determine extent to which chronological age and schooling duration are associated with WM at the population level. METHODS: In 2012, children in Grade 1 (the second year of formal schooling in Victoria, Australia) from 44 schools in metropolitan Melbourne were recruited. Assessments occurred over the entire school year, with schools quasi-randomly allocated to one of the 4 school terms. WM (primary outcome) was measured using 2 subtests from the computerized Automated Working Memory Assessment: Backwards Digit Recall (verbal) and Mister X (visuospatial). Linear regression was used to examine relationships of WM with time in school and age. RESULTS: Of the 1765 who provided consent, 1727 children (97.9%) had WM assessed throughout the 2012 school year. WM scores became steadily higher over the course of the year. Thus, scores were .77 and .53 SDs higher in Term 4 than Term 1 for verbal and visuospatial WM, respectively (p values for trend for both scores <.001); conclusions were unchanged when adjusted for age and potential confounders. Conversely, age associations attenuated fully once adjusted for school duration. CONCLUSIONS: Our results demonstrate, for the first time, that the developmental increases in WM are strongly associated with time spent in the classroom, above and beyond chronological age.

The relation between receptive grammar and procedural, declarative, and working memory in specific language impairment

What memory systems underlie grammar in children, and do these differ between typically developing (TD) children and children with specific language impairment (SLI)? Whilst there is substantial evidence linking certain memory deficits to the language problems in children with SLI, few studies have investigated multiple memory systems simultaneously, examining not only possible memory deficits but also memory abilities that may play a compensatory role. This study examined the extent to which procedural, declarative, and working memory abilities predict receptive grammar in 45 primary school aged children with SLI (30 males, 15 females) and 46 TD children (30 males, 16 females), both on average 9;10 years of age. Regression analyses probed measures of all three memory systems simultaneously as potential predictors of receptive grammar. The model was significant, explaining 51.6% of the variance. There was a significant main effect of learning in procedural memory and a significant group × procedural learning interaction. Further investigation of the interaction revealed that procedural learning predicted grammar in TD but not in children with SLI. Indeed, procedural learning was the only predictor of grammar in TD. In contrast, only learning in declarative memory significantly predicted grammar in SLI. Thus, different memory systems are associated with receptive grammar abilities in children with SLI and their TD peers. This study is, to our knowledge, the first to demonstrate a significant group by memory system interaction in predicting grammar in children with SLI and their TD peers. In line with Ullman's Declarative/Procedural model of language and procedural deficit hypothesis of SLI, variability in understanding sentences of varying grammatical complexity appears to be associated with variability in procedural memory abilities in TD children, but with declarative memory, as an apparent compensatory mechanism, in children with SLI.

Short-term changes in endogenous estrogen levels and consumption of soy isoflavones affect working and verbal memory in young adult females

Estrogen is known to modulate certain cognitive functions, most notably improving working memory and verbal memory. Soy foods contain isoflavones, phytoestrogens structurally similar to estrogen that weakly bind to estrogen receptors.We investigated the effects of natural variations in estrogen levels and short-term dietary supplementation with soy isoflavones on cognitive function in 28 young women. Performance was examined across a range of cognitive tasks on three occasions during separate menstrual cycles: during a menses phase (low estrogen), during a luteal phase (highest estrogen), and once during a menses phase after a 3-day phytoestrogen-rich dietary intervention. Soy supplementation during menses led to an improvement in working memory and verbal memory. The menstrual cycle effects were mixed, with high estrogen improving performance on a verbal memory task but not on working memory. Our results suggest that soy phytoestrogens may improve working memory through estrogen-independent mechanisms.