A comparison of working memory skills and learning in children with developmental coordination disorder and moderate learning difficulties

The present study compared 6–11 years old with developmental coordination disorder (DCD) and those with moderate learning difficulties (MLD) on measures of memory (verbal short‐term and working memory, visuo‐spatial short‐term and working memory), literacy and numeracy, and IQ. The findings indicate that children with DCD appear to be impaired in all four areas of memory function; in particular they performed at significantly lower levels than children with MLD in measures of verbal short‐term memory, visuo‐spatial short‐term and working memory. In contrast, performance of children with MLD in the memory measures was within age‐expected levels, with deficits observed only in verbal working memory tasks. There were also differential links between memory and attainment between the two groups, and these were significant even after statistically accounting for the contribution of IQ. Reasons for why working memory contributes to learning in these two developmental groups are discussed. Copyright © 2006 John Wiley & Sons, Ltd.     

Learning a map of environment: The role of visuo‐spatial abilities in young and older adults

The present study examines age‐related differences between young and older adults in spatial mental representation derived from learning a realistic city map. A sample of 30 young (20–30‐years) and 30 older (60–72 years) adults learned a simplified map of a city; afterwards participants performed map‐drawing and pointing‐aligned and counter‐aligned tasks. Tasks measuring visuo‐spatial abilities were also administered to explore their relationship with map learning. Results showed an age‐related impairment in older adults in both map tasks, as well as in visuo‐spatial ones. Furthermore, performance on counter‐aligned pointing was poorer than on aligned pointing in young and older adults, and its relationship with visuo‐spatial abilities changed as a function of age group: The performance of counter‐aligned pointing in older adults was related to all visuo‐spatial abilities, and in young adults with perspective‐taking measures only. Copyright © 2011 John Wiley & Sons, Ltd.     

The structure of working memory abilities across the adult life span

The present study addresses three questions regarding age differences in working memory: (1) whether performance on complex span tasks decreases as a function of age at a faster rate than performance on simple span tasks; (2) whether spatial working memory decreases at a faster rate than verbal working memory; and (3) whether the structure of working memory abilities is different for different age groups. Adults, ages 20-89 (n = 388), performed three simple and three complex verbal span tasks and three simple and three complex spatial memory tasks. Performance on the spatial tasks decreased at faster rates as a function of age than performance on the verbal tasks, but within each domain, performance on complex and simple span tasks decreased at the same rates. Confirmatory factor analyses revealed that domain-differentiated models yielded better fits than models involving domain-general constructs, providing further evidence of the need to distinguish verbal and spatial working memory abilities. Regardless of which domain-differentiated model was examined, and despite the faster rates of decrease in the spatial domain, age group comparisons revealed that the factor structure of working memory abilities was highly similar in younger and older adults and showed no evidence of age-related dedifferentiation.     

The development of creative cognition across adolescence: distinct trajectories for insight and divergent thinking

We examined developmental trajectories of creative cognition across adolescence. Participants (N = 98), divided into four age groups (12/13 yrs, 15/16 yrs, 18/19 yrs, and 25–30 yrs), were subjected to a battery of tasks gauging creative insight (visual; verbal) and divergent thinking (verbal; visuo‐spatial). The two older age groups outperformed the two younger age groups on insight tasks. The 25–30‐year‐olds outperformed the two youngest age groups on the originality measure of verbal divergent thinking. No age‐group differences were observed for verbal divergent thinking fluency and flexibility. On divergent thinking in the visuo‐spatial domain, however, only 15/16‐year‐olds outperformed 12/13‐year‐olds; a model with peak performance for 15/16‐years‐old showed the best fit. The results for the different creativity processes are discussed in relation to cognitive and related neurobiological models. We conclude that mid‐adolescence is a period of not only immaturities but also of creative potentials in the visuo‐spatial domain, possibly related to developing control functions and explorative behavior.     

Cognitive components of a mathematical processing network in 9‐year‐old children

We determined how various cognitive abilities, including several measures of a proposed domain‐specific number sense, relate to mathematical competence in nearly 100 9‐year‐old children with normal reading skill. Results are consistent with an extended number processing network and suggest that important processing nodes of this network are phonological processing, verbal knowledge, visuo‐spatial short‐term and working memory, spatial ability and general executive functioning. The model was highly specific to predicting arithmetic performance. There were no strong relations between mathematical achievement and verbal short‐term and working memory, sustained attention, response inhibition, finger knowledge and symbolic number comparison performance. Non‐verbal intelligence measures were also non‐significant predictors when added to our model. Number sense variables were non‐significant predictors in the model and they were also non‐significant predictors when entered into regression analysis with only a single visuo‐spatial WM measure. Number sense variables were predicted by sustained attention. Results support a network theory of mathematical competence in primary school children and falsify the importance of a proposed modular ‘number sense’. We suggest an ‘executive memory function centric’ model of mathematical processing. Mapping a complex processing network requires that studies consider the complex predictor space of mathematics rather than just focusing on a single or a few explanatory factors.     

Mind–culture interactions: How writing molds mental fluidity in early development

This study investigated intellectual development in 4–7 years old Greek and Chinese children. They were examined on speeded performance, working memory, reasoning, and self-awareness tasks in order to investigate possible effects of learning the Chinese logographic system on possible differences in intellectual development between these ethnic groups. Speeded performance was examined with commonly familiar objects and tasks related to reading (i.e., Latin, Arabic, and Chinese characters). Chinese outperformed Greeks in (1) reading-related processing efficiency tasks but not in common objects (2) spatial but not verbal WM, (3) cognitive, and (4) the self-awareness tasks. Structural equation modeling showed that performance is organized in four systems (i.e., domain-specific problem solving, representational capacity, inference, and consciousness) integrated by g, in both ethnic groups. There were differences between the two ethnicities in the strength of relations between constructs, attributed to Chinese logographic experience. That is, the massive practice in visuo/spatial processing and memory seemed to provide an advantage in the communication between systems of the mind causing increased general cognitive fluidity, expressed in higher intellectual performance among the Chinese.     

Visuo‐spatial play experience: forerunner of visuo‐spatial achievement in preadolescent and adolescent boys and girls?

This cross‐sectional study explored whether participation, from early childhood, in play involving different cognitive abilities predicts visuo‐spatial achievement at ages 9, 12, and 15. Based on parental assessment, prior and present practice of spatial manipulation play was found to be consistently more frequent in boys than in girls; the reverse held true for verbal expression play. Whereas boys did not significantly outperform girls in three visuo‐spatial tasks, girls were superior on a contrastive vocabulary task. In general, with IQ statistically controlled, regression analyses showed that estimated past and present spatial manipulation play predicted both genders' proficiency in the water‐level task and Embedded Figures Test, as did mothers' socioeconomic status for Block Design performance. Contrastingly, a negative relation was established between spatial manipulation play and vocabulary scores. Similar to the activity‐ability association often identified among adults, the relation established here between spatial play experience and visuo‐spatial ability was only modest. Further research should aim at more definitive conclusions through augmenting both diversity in the visuo‐spatial skills measured and sophistication in play behaviour appraisal. Copyright © 2003 John Wiley & Sons, Ltd.     

Reasoning strategies: the role of working memory and verbal-spatial ability

Evidence increasingly suggests individual differences in strategies adopted on reasoning tasks and that these are either verbal-propositional or visuospatial in nature. However, the cognitive foundations of these strategies remain uncertain. Experiment 1 examined the relationship between the use of working memory resources and strategy selection for syllogistic reasoning. Verbal and spatial strategy users did not differ on working memory capacity, but confirmatory factor analysis indicated that while verbal reasoners draw primarily on verbal working memory, spatial reasoners use both this and spatial resources. Experiment 2 investigated the relationship between strategies and verbal and spatial abilities. Although strategy groups were similar in overall ability, regression analysis showed that performance on a spatial ability measure (Vandenberg mental rotation task) predicted syllogistic reasoning performance, but only for spatial strategy users. The findings provide converging evidence that verbal and spatial strategies are underpinned by related differences in fundamental cognitive factors, drawing differentially on the subcomponents of working memory and on spatial ability.     

Parental socioeconomic status and the neural basis of arithmetic: differential relations to verbal and visuo‐spatial representations

We examined the relation of parental socioeconomic status (SES) to the neural bases of subtraction in school‐age children (9‐ to 12‐year‐olds). We independently localized brain regions subserving verbal versus visuo‐spatial representations to determine whether the parental SES‐related differences in children's reliance on these neural representations vary as a function of math skill. At higher SES levels, higher skill was associated with greater recruitment of the left temporal cortex, identified by the verbal localizer. At lower SES levels, higher skill was associated with greater recruitment of right parietal cortex, identified by the visuo‐spatial localizer. This suggests that depending on parental SES, children engage different neural systems to solve subtraction problems. Furthermore, SES was related to the activation in the left temporal and frontal cortex during the independent verbal localizer task, but it was not related to activation during the independent visuo‐spatial localizer task. Differences in activation during the verbal localizer task in turn were related to differences in activation during the subtraction task in right parietal cortex. The relation was stronger at lower SES levels. This result suggests that SES‐related differences in the visuo‐spatial regions during subtraction might be based in SES‐related verbal differences.     

Effects of working memory load on long‐term word priming

Three experiments assessed the role of verbal and visuo‐spatial working memory in supporting long‐term repetition priming for written words. In Experiment 1, two priming tasks (word stem completion and category‐exemplar production) were included with three levels of load on working memory: (1) without memory load, (2) memory load that involved storing a string of six digits, and (3) memory load that involved storing a graphic shape. Experiments 2 and 3 compared the effects of a verbal (Experiment 2) or a visual (Experiment 3) working memory load at encoding on both an implicit (word stem completion) and an explicit test (cued recall). The results show no effect of memory load in any of the implicit memory tests, suggesting that priming does not rely on working memory resources. By contrast, loading working memory at encoding causes a significant disruptive effect on the explicit memory test for words when the load is verbal but not visual.     

Role of Verbal Working Memory in Complex Skill Acquisition

Although research has shown that general cognitive ability is related to performance during the initial stage of skill acquisition, empirical evidence is needed to increase understanding of the primary abilities responsible for the relation. We propose that verbal working memory is related to initial skill acquisition performance based on cognitive activities people enact when learning complex skills. After completing a general cognitive ability measure and a test of verbal working memory, 120 undergraduate students performed a complex computer simulation. The working memory test accounted for a meaningful amount of performance variance after statistically controlling for the general cognitive ability measure. These data suggest that tasks depending heavily on the activation of multiple knowledge structures may be understood in terms of individual differences in working memory.     

Training and transfer effects of executive functions in preschool children

Executive functions, including working memory and inhibition, are of central importance to much of human behavior. Interventions intended to improve executive functions might therefore serve an important purpose. Previous studies show that working memory can be improved by training, but it is unknown if this also holds for inhibition, and whether it is possible to train executive functions in preschoolers. In the present study, preschool children received computerized training of either visuo‐spatial working memory or inhibition for 5 weeks. An active control group played commercially available computer games, and a passive control group took part in only pre‐ and posttesting. Children trained on working memory improved significantly on trained tasks; they showed training effects on non‐trained tests of spatial and verbal working memory, as well as transfer effects to attention. Children trained on inhibition showed a significant improvement over time on two out of three trained task paradigms, but no significant improvements relative to the control groups on tasks measuring working memory or attention. In neither of the two interventions were there effects on non‐trained inhibitory tasks. The results suggest that working memory training can have significant effects also among preschool children. The finding that inhibition could not be improved by either one of the two training programs might be due to the particular training program used in the present study or possibly indicate that executive functions differ in how easily they can be improved by training, which in turn might relate to differences in their underlying psychological and neural processes.     

The world of competitive Scrabble: Novice and expert differences in visuopatial and verbal abilities

Competitive Scrabble players spend a mean of 4.5 hr a week memorizing words from the official Scrabble dictionary. When asked if they learn word meanings when studying word lists, only 6.4% replied "always," with the rest split between "sometimes" and "rarely or never." Number of years of play correlated positively with expertise ratings, suggesting that expertise develops with practice. To determine the effect of hours of practice (M = 1,904), the authors compared experts with high-achieving college students on a battery of cognitive tests. Despite reporting that they usually memorize word lists without learning meanings, experts defined more words correctly. Reaction times on a lexical decision task (controlling for age) correlated with expertise ratings, suggesting that experts develop faster access to word identification. Experts' superiority on visuospatial processing was found for reaction time on 1 of 3 visuospatial tests. In a study of memory for altered Scrabble boards, experts outperformed novices, with differences between high and low expertise on memory for boards with structure-deforming transformations. Expert Scrabble players showed superior performance on selected verbal and visuospatial tasks that correspond to abilities that are implicated in competitive play.     

Individual and developmental differences in working memory across the life span

The effects of secondary tasks on verbal and spatial working memory were examined in multiple child, young adult, and older adult samples. Although memory span increased with age in the child samples and decreased with age in the adult samples, there was little evidence of systematic change in the magnitude of interference effects. Surprisingly, individuals who had larger memory spans when there was no secondary task showed greater interference effects than their age-mates. These findings are inconsistent with the hypothesis that age and individual differences in working memory are due to differences in the ability to inhibit irrelevant information, at least as this hypothesis is currently formulated. Moreover, our results suggest that different mechanisms underlie developmental and individual differences in susceptibility to interference across the life span. A model is proposed in which memory span and processing speed both increase with development but are relatively independent abilities within age groups.     

Individual Differences in the Encoding Processes of Egocentric and Allocentric Survey Knowledge

This study examined how different components of working memory are involved in the acquisition of egocentric and allocentric survey knowledge by people with a good and poor sense of direction (SOD). We employed a dual‐task method and asked participants to learn routes from videos with verbal, visual, and spatial interference tasks and without any interference. Results showed that people with a good SOD encoded and integrated knowledge about landmarks and routes into egocentric survey knowledge in verbal and spatial working memory, which is then transformed into allocentric survey knowledge with the support of all three components, distances being processed in verbal and spatial working memory and directions in visual and spatial working memory. In contrast, people with a poor SOD relied on verbal working memory and lacked spatial processing, thus failing to acquire accurate survey knowledge. Based on the results, a possible model for explaining individual differences in spatial knowledge acquisition is proposed.     

Performance dissociation during verbal and spatial working memory tasks

Past research has inconsistently distinguished the neural substrates of various types of working memory. Task design and individual performance differences are known to alter patterns of brain response during working-memory tasks. These task and individual differences may have produced discrepancies in imaging findings. This study of 50 healthy adults (M(age) = 19.6 yr., SD = .8) examined performance during various parametric manipulations of a verbal and spatial n-back working-memory task. Performance systematically dissociated on the basis of working-memory load, working memory type, and stimulus difficulty, with participants having greater accuracy but slower response time during conditions requiring verbal versus spatial working memory. These findings hold implications for cognitive and neuroimaging studies of verbal and spatial working memory and highlight the importance of considering both task design and individual behavior.     

Domain‐specific and domain‐general precursors of mathematical achievement: A longitudinal study from kindergarten to first grade

Background. Many contributing factors, both domain specific and domain general, influence children's performance in school achievement. Aims. This research aims to verify the importance of kindergarten measures of cognitive abilities and numerical competence in the role of predicting mathematical school achievement at the end of first grade. Sample and Methods. A total of 70 children (38 females and 32 males) took part in the study. We tested the children at the beginning of their last year of kindergarten (time 1) on the following cognitive abilities: IQ, phonology, counting skills, verbal short‐term memory, visuo‐spatial short‐term memory, working memory, and processing speed. Then, we tested the same children at end of their last year of kindergarten (time 2) on a measure of numerical competence and at the end of their first year of primary school (time 3) on a test of math achievement. Results. Path analysis models revealed the direct influence of working memory and processing speed on predicting numerical competence in pre‐schoolers and the influence of processing speed and verbal IQ on predicting math achievement in first graders. Moreover, this study found a direct link between numerical competence and math achievement. Conclusions. Both domain‐specific and domain‐general factors contribute to determining math achievement at the end of first grade.