Working Memory and Cognitive Skills in Individuals with Down Syndrome

This work is aimed at analyzing working memory (WM) components and their relationships with other cognitive processes in individuals with Down syndrome (DS). Particular attention is given to examine whether a verbal WM deficit is due to difficulties in verbal abilities often showed by individuals with DS, or whether it is a deficit per se. A group of 20 individuals with DS was compared to a group of 20 typically developing (TD) children matched on vocabulary comprehension and to a group of 20 TD children matched on general verbal intelligence. The groups received a battery of 3 verbal and 3 visuospatial WM tasks requiring different degrees of control, and tests assessing verbal abilities (WPPSI verbal scale, PPVT), nonverbal skills (WPPSI performance scale), and logical thinking (LO). The results revealed that individuals with DS have deficits in both central executive (control) and verbal components of the WM system, and the latter one is independent of the general verbal abilities deficit. The data suggest that the development of central executive proceeds at a slower rate in individuals with DS and differently from TD children with comparable verbal abilities. The performance of individuals with DS on high-control WM tasks requires additional general resources that are strictly linked to intelligence.     

Verbal Working Memory as a Longitudinal Mechanism of Vocabulary Problems in Preschoolers with ADHD

Elucidation of early potential risk factors of Attention-Deficit/Hyperactivity Disorder (ADHD) is important to allow for early identification of ADHD and targeted early intervention for children with ADHD. Delayed language skills, particularly poor vocabulary, is an early-developing potential risk factor that is thought to be involved in developmental pathways to ADHD; however, mechanisms explaining the relationship between poor vocabulary skills and ADHD symptoms are unclear and warrant investigation. The present study examines the relationship between poor vocabulary skills and ADHD symptoms by testing cognitive mechanisms, namely verbal working memory (WM), that might account for this link. Participants were 109 young children between the ages of three and six and their primary caregivers. Diagnostic information on ADHD symptoms was available from parents and teachers/daycare providers via standardized rating forms. Vocabulary skills and WM were measured through child performance on laboratory tasks. Mediation analyses found poor verbal working memory significantly partially explained the vocabulary-ADHD association for both parent and teacher-rated ADHD symptoms. Further, effects of verbal WM on the association between poor vocabulary and increased ADHD symptoms largely held at one-year follow-up. Development of early interventions targeting verbal WM may be a promising new direction for early ADHD intervention work.     

Working Memory and Spoken Language Comprehension in Young Children

This study has two theoretical dimensions: (a) to explore which components of Baddeley's (1986) working memory model are associated with children's spoken language comprehension, and (b) to compare the extent to which measures of the components of this fractionated model and an index of a unitary model (listening span) are able to predict individual differences in spoken language comprehension. Correlational analyses revealed that within a group of 66 4– and 5-year-old children both listening span and phonological memory, but not visuospatial memory, were associated with vocabulary knowledge and spoken language comprehension. However, of the proposed measures of central executive function—dual task coordination, sustained attention, verbal fluency—only the latter was related to children's ability to understand spoken language. Hierarchical regression analyses indicated that variance in vocabulary knowledge was best explained by phonological memory skills, whereas individual differences in spoken language comprehension exhibited unique and independent associations with verbal fluency.     

Writing abilities and the role of working memory in children with symptoms of attention deficit and hyperactivity disorder

The writing abilities of children with ADHD symptoms were examined in a simple dictation task, and then in two conditions with concurrent verbal or visuospatial working memory (WM) loads. The children with ADHD symptoms generally made more spelling mistakes than controls, and the concurrent loads impaired their performance, but with partly different effects. The concurrent verbal WM task prompted an increase in the phonological errors, while the concurrent visuospatial WM task prompted more non-phonological errors, matching the Italian phonology, but not the Italian orthography. In the ADHD group, the children proving better able to cope with a concurrent verbal WM load had a better spelling performance too. The ADHD and control groups had a similar handwriting speed, but the former group’s writing quality was poorer. Our results suggest that WM supports writing skills, and that children with ADHD symptoms have general writing difficulties, but strength in coping with concurrent verbal information may support their spelling performance.     

Working memory resources in young children with mathematical difficulties

Kyttälä, M., Aunio, P. & Hautamäki, J. (2010). Working memory resources in young children with mathematical difficulties. Scandinavian Journal of Psychology, 51 , 1–15.
Working memory (WM) ( Baddeley, 1986, 1997 ) is argued to be one of the most important cognitive resources underlying mathematical competence ( Geary, 2004 ). Research has established close links between WM deficits and mathematical difficulties. This study investigated the possible deficits in WM, language and fluid intelligence that seem to characterize 4- to 6-year-old children with poor early mathematical skills before formal mathematics education. Children with early mathematical difficulties showed poor performance in both verbal and visuospatial WM tasks as well as on language tests and a fluid intelligence test indicating a thoroughly lower cognitive base. Poor WM performance was not moderated by fluid intelligence, but the extent of WM deficits was related to language skills. The educational implications are discussed.     

A comparison of working memory profiles in school-aged children with Specific Language Impairment,Attention Deficit/Hyperactivity Disorder,Comorbid SLI and ADHD and their typically developing peers

The association between specific language impairment (SLI), attention deficit/hyperactivity disorder (ADHD), and working memory (WM) was examined. WM has been implicated in language acquisition and models of ADHD; however, evidence for WM deficits in SLI and ADHD has been inconsistent. The components of Baddeley's WM model were investigated in 18 children with SLI, 16 children with ADHD, 11 children with comorbid SLI+ADHD, and 24 typically developing (TD) children. The presence of SLI resulted in deficits in more components of WM than the presence of ADHD indicating that children with SLI are more vulnerable to WM deficits than those with ADHD.     

A comparison of working memory profiles in school-aged children with Specific Language Impairment, Attention Deficit/Hyperactivity Disorder, Comorbid SLI and ADHD and their typically developing peers

The association between specific language impairment (SLI), attention deficit/hyperactivity disorder (ADHD), and working memory (WM) was examined. WM has been implicated in language acquisition and models of ADHD; however, evidence for WM deficits in SLI and ADHD has been inconsistent. The components of Baddeley's WM model were investigated in 18 children with SLI, 16 children with ADHD, 11 children with comorbid SLI+ADHD, and 24 typically developing (TD) children. The presence of SLI resulted in deficits in more components of WM than the presence of ADHD indicating that children with SLI are more vulnerable to WM deficits than those with ADHD.     

Effects of impoverished environmental conditions on working memory performance

This cross-cultural study investigates the impact of background experience on four verbal and visuo-spatial working memory (WM) tasks. A total of 84 children from low-income families were recruited from the following groups: (1) Portuguese immigrant children from Luxembourg impoverished in terms of language experience; (2) Brazilian children deprived in terms of scholastic background; (3) Portuguese children from Portugal with no disadvantage in either scholastic or language background. Children were matched on age, gender, fluid intelligence, and socioeconomic status and completed four simple and complex span tasks of WM and a vocabulary measure. Results indicate that, despite large differences in their backgrounds and language abilities, the groups exhibited comparable performance on the visuo-spatial tasks dot matrix and odd-one-out and on the verbal simple span task digit recall. Group differences emerged on the verbal complex span task counting recall with children from Luxembourg and Portugal outperforming children from disadvantaged schools in Brazil. The study suggests that whereas contributions of prior knowledge to digit span, dot matrix, and odd-one-out are likely to be minimal, background experience can affect performance on counting recall. Implications for testing WM capacity in children growing up in poverty are discussed.     

Auditory lexical decisions in children with specific language impairment

This study examined spoken‐word recognition in children with specific language impairment (SLI) and normally developing children matched separately for age and receptive language ability. Accuracy and reaction times on an auditory lexical decision task were compared. Children with SLI were less accurate than both control groups. Two subgroups of children with SLI, distinguished by performance accuracy only, were identified. One group performed within normal limits, while a second group was significantly less accurate. Children with SLI were not slower than the age‐matched controls or language‐matched controls. Further, the time taken to detect an auditory signal, make a decision, or initiate a verbal response did not account for the differences between the groups. The findings are interpreted as evidence for language‐appropriate processing skills acting upon imprecise or underspecified stored representations.     

What Part of Working Memory is not Working in ADHD? Short-Term Memory, the Central Executive and Effects of Reinforcement

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.     

Predictors of reading fluency in Italian orthography: Evidence from a cross-sectional study of primary school students

This study investigates the role of linguistic and visuospatial attentional processes in predicting reading fluency in typical Italian readers attending primary school. Tasks were administered to 651 children with reading fluency z scores > ?1.5 standard deviation to evaluate their phonological awareness, rapid automatized naming (RAN), verbal short-term memory, vocabulary, visual search skills, verbal-visual recall, and visual-spatial attention. Hybrid models combining confirmatory factor analysis and path analysis were used to evaluate the data obtained from younger (first and second grade) and older (third–fifth grade) children, respectively. The results showed that phonological awareness and RAN played a significant role among younger children, while also vocabulary, verbal short-term memory, and visuospatial attention were significant factors among older children.     

Language Development and Assessment in the Preschool Period

Most young children make significant progress in learning language during the first 4?years of life. Delays or differences in patterns of language acquisition are sensitive indicators of developmental problems. The dynamic, complex nature of language and the variability in the timing of its acquisition poses a number of challenges for the assessment of young children. This paper summarises the key developmental milestones of language development in the preschool years, providing a backdrop for understanding difficulties with language learning. Children with specific language impairment (SLI) are characterised illustrating the types of language difficulties they exhibit. Genetic evidence for language impairment suggests complex interactions among multiple genes of small effect. There are few consistent neurobiological abnormalities and currently there is no identified neurobiological signature for language difficulties. The assessment of young children??s language skills thus focuses on the evaluation of their performances in comparison to typically developing peers. Assessment of language abilities in preschool children should involve an evaluation of both expressive and receptive skills and should include an evaluation of more than one dimension of language. The use of a single measure of a language component, such as vocabulary, is considered inadequate for determining whether preschool children have typical language or language impairment. Available evidence supports the inclusion of measures of phonological short-term memory in the assessment of the language abilities of preschool children. Further study of genetic, neurobiological and early behavioural correlates of language impairments in preschool children is needed.     

Working memory and vocabulary development in Greek preschool and primary school children

The present research investigated the relative contributions of verbal short-term memory (STM) and working memory (WM) to vocabulary development in the early years among Greek-speaking children. Participants were 5.5-, 7.5-, 8.5- and 9.5-year-old (N = 216) native speakers of Greek, a language differing from English in which most investigations have been conducted. Children were assessed with a receptive vocabulary task, four verbal STM measures (word, digit, and non-word list recall, as well as word list matching), and three verbal WM tasks (listening, counting, and backward digit recall). Results offer support to the view that both STM and WM influence vocabulary development in early stages. Vocabulary was associated with verbal STM at 7.5 and 8.5 years, but only with verbal WM at 5.5 years. Associations declined with age (by 9.5 years), earlier than in English-speaking children. Findings are discussed in relation to Greek language characteristics, demonstrating the importance of cross-cultural investigations.     

Preschool language and visuospatial skills respectively predict multiplication and addition/subtraction skills in middle school children

A converging body of evidence from neuroimaging, behavioral, and neuropsychology studies suggests that different arithmetic operations rely on distinct neuro-cognitive processes: while addition and subtraction may rely more on visuospatial reasoning, multiplication would depend more on verbal abilities. In this paper, we tested this hypothesis in a longitudinal study measuring language and visuospatial skills in 358 preschoolers, and testing their mental calculation skills at the beginning of middle school. Language skills at 5.5 years significantly predicted multiplication, but not addition nor subtraction scores at 11.5 years. Conversely, early visuospatial skills predicted addition and subtraction, but not multiplication scores. These results provide strong support for the existence of a double dissociation in mental arithmetic operations, and demonstrate the existence of long-lasting links between language/visuospatial skills and specific calculation abilities.     

Imitation of body postures and hand movements in children with specific language impairment

Within the domain-general theory of language impairment, this study examined body posture and hand movement imitation in children with specific language impairment (SLI) and in their age-matched peers. Participants included 40 children with SLI (5 years 3 months to 6 years 10 months of age) and 40 children with typical language development (5 years 3 months to 6 years 7 months of age). Five tests were used to examine imitation and its underlying cognitive and motor skills such as kinesthesia, working memory, and gross motor coordination. It was hypothesized that children with SLI show a weakness in imitation of body postures and that this deficit is not equally influenced by the underlying cognitive and motor skills. There was a group effect in each cognitive and motor task, but only gross motor coordination proved to be a strong predictor of imitation in children with SLI. In contrast, hand movement imitation was strongly predicted by performance in the Kinesthesia task in typically developing children. Thus, the findings show not only that children with SLI performed more poorly on the imitation tasks than their typically developing peers but also that the groups’ performances showed qualitative differences. The results of the current study provide additional support to the view that the weaknesses in children with SLI are not limited to the verbal domain.     

Children's associations between space and pitch are differentially shaped by language

Musical properties, such as auditory pitch, are not expressed in the same way across cultures. In some languages, pitch is expressed in terms of spatial height (high vs. low), whereas others rely on thickness vocabulary (thick = low frequency vs. thin = high frequency). We investigated how children represent pitch in the face of this variable linguistic input by examining the developmental trajectory of linguistic and non-linguistic space-pitch associations in children who acquire Dutch (a height-pitch language) or Turkish (a thickness-pitch language). Five-year-olds, 7-year-olds, 9-year-olds, and 11-year-olds were tested for their understanding of pitch terminology and their associations of spatial dimensions with auditory pitch when no language was used. Across tasks, thickness-pitch associations were more robust than height-pitch associations. This was true for Turkish children, and also Dutch children not exposed to thickness-pitch vocabulary. Height-pitch associations, on the other hand, were not reliable—not even in Dutch-speaking children until age 11—the age when they demonstrated full comprehension of height-pitch terminology. Moreover, Turkish-speaking children reversed height-pitch associations. Taken together, these findings suggest thickness-pitch associations are acquired in similar ways by children from different cultures, but the acquisition of height-pitch associations is more susceptible to linguistic input. Overall, then, despite cross-cultural stability in some components, there is variation in how children come to represent musical pitch, one of the building blocks of music.

Research Highlights

• Children from diverse cultures differ in their understanding of music vocabulary and in their nonlinguistic associations between spatial dimensions and auditory pitch.
• Height-pitch mappings are acquired late and require additional scaffolding from language, whereas thickness-pitch mappings are acquired early and are less susceptible to language input.
• Space-pitch mappings are not static from birth to adulthood, but change over development, suggesting music cognition is shaped by cross-cultural experience.

     

Individual differences in the shape bias in preschool children with specific language impairment and typical language development: theoretical and clinical implications

We investigated whether preschool children with specific language impairment (SLI) exhibit the shape bias in word learning: the bias to generalize based on shape rather than size, color, or texture in an object naming context (‘This is a wek; find another wek’) but not in a non‐naming similarity classification context (‘See this? Which one goes with this one?’). Fifty‐four preschool children (16 with SLI, 16 children with typical language [TL] in an equated control group, and 22 additional children with TL included in individual differences analyses but not group comparisons) completed a battery of linguistic and cognitive assessments and two experiments. In Experiment 1, children made generalization choices in object naming and similarity classification contexts on separate days, from options similar to a target object in shape, color, or texture. On average, TL children exhibited the shape bias in an object naming context, but children with SLI did not. In Experiment 2, we tested whether the failure to exhibit the shape bias might be linked to ability to detect systematicities in the visual domain. Experiment 2 supported this hypothesis, in that children with SLI failed to learn simple paired visual associations that were readily learned by children with TL. Analyses of individual differences in the two studies revealed that visual paired‐associate learning predicted degree of shape bias in children with SLI and TL better than any other measure of nonverbal intelligence or standard assessments of language ability. We discuss theoretical and clinical implications.     

Selective Association Between Tetris Game Play and Visuospatial Working Memory: A Preliminary Investigation

Recent experimental and clinical research has suggested that Tetris game play can disrupt maladaptive forms of mental imagery because Tetris competes for limited cognitive resources within visuospatial working memory (WM) that contribute to imagery. Whether or not Tetris performance is selectively associated with visuospatial WM remains to be tested. In this study, young adults (N = 46) completed six standardized measures indexing verbal and non‐verbal reasoning, verbal and visuospatial short‐term memory, and verbal and visuospatial WM. They also played Tetris. Consistent with the hypothesis that visuospatial WM resources support Tetris game play, there was a significant moderate positive relationship between Tetris scores and visuospatial WM performance but no association with other cognitive ability measures. Findings suggest that Tetris game play involves both storage and processing resources within visuospatial WM. These preliminary results can inform interventions involving computer games to disrupt the development of maladaptive visual imagery, for example, intrusive memories of trauma. © 2017 The Authors. Applied Cognitive Psychology Published by John Wiley & Sons Ltd.     

Oral language deficits in dyslexic children: weaknesses in working memory and verbal planning

This paper focuses on the relationships among language processing (word- and sentence-level), working memory, and verbal/nonverbal linguistic output. The study examined oral language abilities in a group of 26 French-speaking dyslexic children, compared to two control groups (26 normally developing age-matched children and 26 normally developing younger children). The experimental procedure consisted of tasks involving auditory memory skills (digit span, unfamiliar word repetition, sentence repetition), word retrieval (with semantic, phonological and grammatical criteria), and sentence processing (with verbal and act-out production). The major findings reveal that (a) compared with their age-mates, the dyslexic children exhibited a significant deficit affecting all tasks; and (b) the dyslexic children and the younger controls performed similarly on several tasks. The results are consistent with the processing limitation hypothesis and suggest that the core deficit is the formulation of cognitive plans from auditory input to verbal output.     

Prediction of fine motor skills of children having language and speech disorders

Relationships between the fine motor skills and linguistic abilities of 37 developmentally delayed children, ages 5 to 9 yr., were studied using a battery of expressive and receptive language tests, a measure of fine motor performance, a dichotic listening test, and individual intelligence tests. While IQs and MAs were not related to fine motor skills, both expressive and receptive language test scores showed moderate to moderately high correlations, the highest single relationship being the Test for the Auditory Comprehension of Language. In concert with CAs, a dichotic right-ear test score, the Auditory Comprehension Test, predicted fine motor-skill indices substantially; R = .80. Strong relationships appear between linguistic and fine motor skills in an age group not previously investigated and at higher levels than reported in studies of infants and very young children. Dichotic results were abnormal in a majority of the children.