Working memory and second language development: A complex, dynamic future?

Developmental research provides considerable evidence of a strong relationship between verbal and visuospatial working memory (WM) and mathematics ability across age groups. However, little is known about how components of WM (i.e., short-term storage, processing speed, the central executive) might relate to mathematics sub-categories and how these change as children develop. This study aimed to identify developmental changes in relationships between components of verbal and visuospatial WM and specific mathematics abilities. Children (n = 117) were recruited from four UK schools across three age groups (7-8 years; 9-10 years; and 14-15 years). Children's verbal and visuospatial short-term storage, processing speed, and central executive abilities were assessed. Age-based changes in the contributions from these abilities to performance on mathematics sub-categories were examined. When WM was examined both as an amalgamation of its component parts, and individually, relationships with mathematics were more evident in younger children compared to the middle and older age groups. However, when unique variance was examined for each WM predictor (controlling for the other components), many of those relationships disappeared. Relationships with processing speed and the central executive were found to be more evident in the older age groups. The WM-mathematics relationship changes dependent on age and mathematical sub-component. Overlap in individual WM abilities in younger children, compared to reliance on the central executive and processing speed in older children, suggests a set of fluid resources important in mathematics learning in younger children but separating out as children grow older.

By administering Simon, Simon switching, and operation-span working memory tasks to Cantonese-English bilingual children who varied in their first-language (L1, Cantonese) and second-language (L2, English) proficiencies, as quantified by standardized vocabulary test performance, the current study examined the effects of L1 and L2 proficiency on attentional control performance. Apart from mean performance, we conducted ex-Gaussian analyses to capture the modal and positive-tail components of participants' reaction time distributions in the Simon and Simon switching tasks. Bilinguals' L2 proficiency was associated with higher scores in the operation span task, and a shift of reaction time distributions in incongruent trials, relative to congruent trials (Simon effect in μ), and the tail size of reaction time distributions (τ) regardless of trial types in the Simon task. Bilinguals' L1 proficiency, which was strongly associated with participants' age, showed similar results, except that it was not associated with the Simon effect in μ. In contrast, neither bilinguals' L1 nor L2 proficiency modulated the global switch cost or local switch cost in the Simon switching task. After taking into account potential cognitive maturation by partialling out the participants' age, only (a) scores in the working memory task and (b) RT in incongruent trials and (c) Simon effect in μ in the Simon task could still be predicted by bilinguals' L2 proficiency. Overall, the current findings suggest that bilingual children's L2 proficiency was associated with their conflict resolution and working memory capacity, but not goal maintenance or task-set switching, when they performed the cognitive tasks that demanded attentional control. This was not entirely consistent with the findings of college-age bilinguals reported in previous studies.

The aim of this review is to systematically examine the literature concerning multicomponent working memory (WM)—comprising a central executive (CE), two storage components (phonological loop, PL and visuo-spatial sketchpad, VSSP), and episodic buffer (EB)—in pediatric traumatic brain injury (TBI). Electronic searches were conducted of MEDLINE, PsychINFO and EMBASE up to October 2014 with the inclusion criteria of children and adolescents with TBI, and quantitative methods to assess at least one component of WM. Meta-analytic procedures calculated pooled effect sizes for WM outcomes. Of the studies examined, 27 met the inclusion criteria. Children with TBI exhibited deficits in the CE and PL, but not in the VSSP, and no study could be found which examined the EB. Qualitative analysis found that greater TBI severity was associated with poorer CE functioning in five out of nine studies. Differences in patterns of brain activation were evident in four out of five fMRI studies that examined WM in TBI children and controls. Deficits in CE were associated with poorer mathematical skills in the only study that examined relations between WM and academic deficits. Notwithstanding the heterogeneity of the studies reviewed, TBI places children at risk of WM deficits. Moreover, this meta-analysis suggests that various components of WM have differential vulnerability to pediatric TBI, with significant deficits found in the CE and PL, but not in the VSSP (although the VSSP has rarely been examined to date). Future studies should be theoretically driven, employ tasks assessing all components of the WM model and examine the functional ramifications (including academic outcomes) of WM deficits in this population.

In the past decades, complex dynamic systems theory (CDST) has been used as an important framework for studying second language development. CDST is a metatheory of change and focuses on processes. Even though it has been broadly accepted as an inspiring dimension of research in psychology, sociology and second language development, some scholars have raised questions about the methodologies used, the interpretation of the data, and the nature of its claims. Specifically, Pallotti questioned whether CDST generates testable hypotheses, and criticized its position towards reductionism and generalizability, based on philosophical argumentations. The present article evaluates the issues addressed, reviews the work that has already been done, and looks ahead at future CDST applications to research in second language development, by exploring recent methodological developments in the field.

Working memory (WM) refers to ability to store and manipulate information for a period of time. There is evidence of a close relationship between WM and learning. The aim of this study was to investigate the relationship between WM, intelligence quotient (IQ) on school achievement. Individual neuropsychological assessment was conducted following a specific protocol. The study included 227 children aged 7 to 12 years (M = 9.87, SD = 1.34), of which 119 were females, from private and public schools in Salvador, Bahia, Brazil. The data analysis included descriptive and inferential statistics. Academic achievement was evaluated using the Academic Performance Test (TDE), with subtests in reading, writing and arithmetic. The components of WM were evaluated using backward and forward Digit Span tasks and the backward and forward Corsi block-tapping task. The estimated IQ was assessed using tasks vocabularies and block design of the Wechsler scales. The statistical tests used were linear regression analysis (stepwise) and Pearson correlation. The results showed that the best predictors of academic performance were Digit Span Forward, Corsi Block Backward and Digit Span Backward task. The hypothesis of non-multicollinearity was tested, and it was verified that the constructs were independent (VIF < 10 and Tolerance > 0.20). The variance in academic performance explained by WM model was ΔR = 0.36. High and significant correlations were observed between the components of WM and the TDE. The WM score (Digit Span Backward + Corsi Block Backward) and the TDE were correlated (r = 0.54**). These results indicate that WM is a good predictor of academic achievement than IQ and are consistent with other findings showing WM as a predictor of learning or the potential for learning. This result has important implications for education, particularly with respect to intervention.

This chapter builds on recent experimental findings to highlight the role of working memory in second language (L2) learning. It surveys the most commonly employed measures of working memory capacity, synthesizes trend-setting empirical evidence that links individual components of working memory to specific learning processes, and uses concrete examples of task features to highlight the impact that working memory can have on L2 performance. The approach here is to introduce the key concepts and connect them to the main research findings relevant to English language learners. Well-established components of working memory are defined, and explanations of their specific function provided, alongside illustrations from openly accessible working memory span tasks for L2 research. Crucially, these are combined with direct applicability in language classroom settings. This chapter centres on two working memory components, phonological and executive. It shows how they influence specific L2 performance (namely new vocabulary learning and grammatical inferencing) and suggests how working memory tests can be effectively integrated into the teaching process. An important message is to show how one component, phonological working memory, is tied more closely to the acquisition of words and semantic features, while a different component, executive working memory, supports attention regulation and self-monitoring during learning. This approach serves here as an encouragement to do classroom-based research on working memory and L2 development, with sensitivity to learners’ individual differences.

Listening comprehension plays a key role in language acquisition, yet little is known about the variables that contribute to the development of second language (L2) listening ability. This study sought to obtain empirical evidence for the impact of some of the learner variables and the degree to which they might predict success in L2 listening. The learner variables of interest included: first language (L1) listening ability, L1 vocabulary knowledge, L2 vocabulary knowledge, auditory discrimination ability, metacognitive awareness of listening, and working memory capacity. Data from 157 Grade Seven students in the first year of a French immersion program indicated a significant relationship among most of the variables and L2 listening ability. A number of path analyses were then conducted, based on hypothetical relationships suggested by current theory and research, in order to uncover relationships between the variables in determining L2 listening comprehension ability. The best fit to the data supported a model in which general skills (auditory discrimination and working memory) are initially important, leading to more specific language skills (L1 and L2 vocabulary) in determining L2 listening comprehension. In positing a provisional model, this study opens up useful avenues for further research on model building in L2 listening.

This study investigated working memory (WM) training for adolescents with perinatal HIV infection, since WM is negatively impacted by the virus, and adolescence is a time of considerable brain reorganization, during which WM functioning reaches maturation. We posed three main questions: 1) whether WM could be trained in adolescents living with HIV, and if so, whether these effects were maintained over a six-month period during which no further training was received; 2) whether there were differential effects of training on the components of WM (verbal and visuospatial storage, verbal and visuospatial processing); 3) whether the WM training transferred to cognate tasks, and if so, whether these transfer effects were maintained over six months. Sixty-three HIV+ adolescents (10–16 years) from two children’s homes were assigned to the training (n = 31) or control (n = 32) group. The training group received 32 hours of supervised training in an adaptive, computerized WM intervention, while the control group received a supervised, placebo computerized program for the same hours. Comprehensive WM and neuropsychological batteries were administered to both groups at pretest, immediately following the intervention, and six months later. Significant improvements were found in verbal WM for the training group, which were maintained six months later. Transfer effects were evident in attention, executive function, memory, language and fluid intelligence. There were no significant posttest improvements in visuospatial storage, and minimal changes in verbal storage and visuospatial WM. These findings represent an important step in exploring ways to improve cognitive functioning in an at-risk population.

Individuals differ in their ability to sustain attention. However, whether differences in sustained attention reflect differences in processes related to attentional control and working memory or long-term memory (LTM) remains underexplored. In Experiment 1, we conducted an online study (n = 136) measuring participants' sustained attention, attention control and working memory, and LTM. We measured sustained attention with an audiovisual continuous performance task in which participants responded to images while inhibiting responses to infrequent targets; attention control and working memory with flanker, change localization, and Simon tasks; and LTM with recognition and source memory tests. Factor analyses revealed that sustained attention formed a distinct factor from attention control and working memory and LTM. Individual differences in the Sustained attention factor robustly predicted individual differences in LTM and, to a lesser extent, attention control and working memory. In Experiment 2, to test how neural signatures of sustained attention related to attention control and working memory and LTM, we analyzed fMRI functional connectivity patterns collected as 20 participants performed the audiovisual continuous performance task. A pretrained connectome-based model of sustained attention predicted participants' performance on out-of-scanner LTM tasks, but not attention control and working memory tasks. Together, these results suggest that individual differences in sustained attention, although correlated with attention control and working memory, are more closely related to LTM.

The present study examines the development of second language (L2) vocabulary in writing comparing two different learning contexts, formal instruction (FI) at home followed by a 3-month stay abroad (SA). Data were obtained from a group of 30 Catalan/Spanish advanced learners of English before and after each learning period by means of a written composition. These compositions were analyzed quantitatively in terms of lexical measures in various domains, such as diversity, density, sophistication and accuracy. Baseline data from 29 native speakers of English, elicited through the same task, were also used for comparison purposes. Our results reveal that the different aspects of lexical proficiency in L2 writing do not develop in the same manner across the two learning contexts. While SA is particularly beneficial for lexical diversity, lexical accuracy seems to flourish after both FI and SA learning periods. Learners also achieve more native-like behaviour in terms of spelling and lexical sophistication after SA. These findings are interpreted together with the relevance of the selected measures used in the study.

Deficits in Working Memory (WM) are related to symptoms of Attention-Deficit/Hyperactivity Disorder (ADHD). In children with ADHD visuospatial WM is most impaired. WM is composed of Short-Term Memory (STM) and a Central Executive (CE). Therefore, deficits in either or both STM and the CE may account for WM impairments in children with ADHD. WM-component studies investigating this find deficits in both STM and the CE. However, recent studies show that not only cognitive deficits, but also motivational deficits give rise to the aberrant WM performance of children with ADHD. To date, the influence of these motivational deficits on the components of WM has not been investigated. This study examined the effects of a standard (feedback-only) and a high level of reinforcement (feedback + 10 euros) on the visuospatial WM-, visuospatial STM-, and the CE performance of 86 children with ADHD and 62 typically-developing controls. With standard reinforcement the STM, CE, and WM performance of children with ADHD was worse than that of controls. High reinforcement improved STM and WM performance more in children with ADHD than in controls, but was unable to normalize their performance. High reinforcement did not appear to improve the CE-related performance of children with ADHD and controls. Motivational deficits have a detrimental effect on both the visuospatial WM performance and the STM performance of children with ADHD. Aside from motivational deficits, both the visuospatial STM and the CE of children with ADHD are impaired, and give rise to their deficits in visuospatial WM.

Working memory, fluid intelligence, and science learning

Do executive functions predict the ability to learn problem-solving principles?

This study examined the independent effects of working memory (WM) and the interactive effects of WM/L2 proficiency and WM/task complexity on L2 written performance. The study followed a within–between-participant factorial design, with two levels of task complexity as the within-participant variable and L2 proficiency and WM as between-participants variables. The outcome measure was L2 writing performance as measured by CAF indices. Two groups of undergraduate students from a degree in English studies were invited to complete the simple and complex version of the “Fire-Chief” task. Task complexity was operationalized in terms of reasoning demands, and tasks were counterbalanced to avoid unwanted order effects. Participants also completed the Oxford Placement Test and a working memory test (n-back). Regarding independent effects, results show that WM did not have an effect on L2 writing performance. In contrast, L2 proficiency was the variable most connected to various dimensions of the text produced. As for interactive effects, no significant interaction between WM, proficiency, or task complexity was found. In contrast, L2 proficiency emerged as the sole significant predictor of L2 writing performance at both levels of task complexity.

Children with hearing loss (HL) have difficulty in performing the complex functions of language, especially in noisy environments. Cognitive processes such as working memory and short-term memory are effective on individual differences in language skills in children with HL. The present study aimed to evaluate the vocabulary and syntax skills in language development areas and working memory of children with HL and to compare these results with those of their peers with normal hearing (NH). In this study, a causal-comparative research model was used to measure vocabulary and syntax skills, which are among the working memory and language development skills of children with NH and those with HL. A total of 88 children, 44 children with HL aged 60 to 107 (months) and age- and gender-matched 44 children with NH, were included in the study. Evaluation was made in two sessions of 20 minutes for each participant. The language development and working memory of 44 children with HL and 44 children with NH were evaluated and the two groups were compared with each other. The Working Memory Scale (WMS) was used to evaluate the working memory of the participants and three subtests (vocabulary, sentence repetition, and sentence comprehension) of the Test of Language Development-Primary Fourth Edition: Turkish Version (TOLD-P:4) were used to evaluate language development. SPSS 23.0 program was used in the analysis of the data. Children with HL obtained lower scores than their peers with NH in all three TOLD-P subtests. Children with HL obtained significantly lower scores in WMS verbal memory and general WMS scores compared with NH children. A positive correlation was found between WMS Verbal Memory Scores and TOLD-P sentence comprehension and sentence repetition scores. WMS Visual Memory Scores predicted the group with HL and all TOLD-P scores and Verbal Memory Scores predicted the group with NH. Working memory skills are the predictor of language comprehension, reasoning, learning, literacy skills, and language development. Thus, including working memory skills as well as language skills in the education programs of children with HL contributes to the children's development.