The structure of working memory and how it relates to intelligence in children

Cognitive benefits of last night's sleep: daily variations in children's sleep behavior are related to working memory fluctuations

BACKGROUND

Recent studies have suggested substantial fluctuations of cognitive performance in adults both across and within days, but very little is known about such fluctuations in children. Children's sleep behavior might have an important influence on their daily cognitive resources, but so far this has not been investigated in terms of naturally occurring within-person variations in children's everyday lives.

METHODS

In an ambulatory assessment study, 110 elementary school children (8-11 years old) completed sleep items and working memory tasks on smartphones several times per day in school and at home for 4 weeks. Parents provided general information about the children and their sleep habits.

RESULTS

We identified substantial fluctuations in the children's daily cognitive performance, self-reported nightly sleep quality, time in bed, and daytime tiredness. All three facets were predictive of performance fluctuations in children's school and daily life. Sleep quality and time in bed were predictive of performance in the morning, and afternoon performance was related to current tiredness. The children with a lower average performance level showed a higher within-person coupling between morning performance and sleep quality.

CONCLUSIONS

Our findings contribute important insights regarding a potential source of performance fluctuations in children. The effect of varying cognitive resources should be investigated further because it might impact children's daily social, emotional, and learning-related functioning. Theories about children's cognitive and educational development should consider fluctuations on micro-longitudinal scales (e.g., day-to-day) to identify possible mechanisms behind long-term changes.

Differences in the intellectual profile of children with intellectual vs. learning disability

The WISC-IV was used to compare the intellectual profile of two groups of children, one with specific learning disorders (SLDs), the other with intellectual disabilities (ID), with a view to identifying which of the four main factor indexes and two additional indexes can distinguish between the groups. We collected information on WISC-IV scores for 267 children (Mage=10.61 [SD=2.51], range 6-16 years, females=99) with a diagnosis of either SLD or ID. Children with SLD performed better than those with ID in all measures. Only the SLD children, not the ID children, revealed significant differences in the four main factor indexes, and their scores for the additional General Ability Index (GAI) were higher than for the Cognitive Proficiency Index (CPI). Children with a diagnosis of SLD whose Full-Scale Intelligence Quotient (FSIQ) was <85 showed a similar pattern. Our findings confirm the hypothesis that children with SLD generally obtain high GAI scores, but have specific deficiencies relating to working memory and processing speed, whereas children with ID have a general intellectual impairment. These findings have important diagnostic and clinical implications and should be considered when making diagnostic decisions in borderline cognitive cases.

The children's psychological processes scale: factor structure and correlations with performance-based measures

OBJECTIVE

The current study investigated the internal structure and external relations of the Children's Psychological Processes Scale (CPPS).

METHOD

Principal components analysis and exploratory factor analysis were conducted. Concurrent validity studies were also completed with the Behavior Rating Inventory of Executive Function (BRIEF) and Woodcock-Johnson III Tests of Cognitive Abilities (WJ III COG).

RESULTS

A general cognitive ability factor was identified that accounted for up to 85% of the scale's total variance. Exploratory factor analysis produced a three-factor solution that included general processing ability, executive functions, and visual-motor processing. Subscales comprising the CPPS executive functions factor were found to have high correlations with BRIEF composites and subscales. CPPS subscale correlations with comparable WJ III COG tests indicated that the majority of the CPPS subscales assess the same constructs as those measured by the WJ III COG.

CONCLUSION

The results suggest that rating scale measures of cognitive and metacognitive processes assess the same latent factors and cognitive processes as performance-based measures.

The Crucial Role of Working Memory in Intellectual Functioning

Cognitive psychology offers an important contribution to the understanding of the mechanisms underlying intelligence. In this paper, we synthesize the research showing that, among the different cognitive mechanisms associated with intelligence, working memory has a particularly high explanatory power, especially when considered in its active component involving not only the maintenance (as in short-term memory) but also the manipulation of information. The paper considers two main implications of this finding for the applied and clinical fields. For a start, we examine how intelligence tests take into consideration working memory. Secondly, we consider the highly debated literature on the effects of working memory training on intellectual performance. Theoretical and applied implications for the relationship between working memory and intelligence are discussed.

Task structure complexity and goal neglect in typically developing children

Goal neglect is a failure to enact task requirements despite being able to accurately report them. In this study, we introduce a new child-appropriate experimental paradigm to measure goal neglect in children between 7 and 11 years of age and test the hypothesis that the complexity of an action plan, not real-time trial demands, increases goal neglect. A total of 66 children (Mage=9.50 years) were administered a Feature Match task. Half of the children were given four rules for matching, and half were given three rules for matching. After practice, the four-rules group was told to ignore the additional rule, and both groups completed an identical three-rules task. The results showed that the extra rule increased goal neglect and its correlation with fluid intelligence. Although intermittent trial errors were correlated with fluid intelligence for both groups, only in the four-rules group were systematic rule failures (i.e., goal neglect) correlated with fluid intelligence. Task performance improved with chronological age; however, when controlling for the influence of fluid intelligence, the relationship between age and task performance was effectively removed. This suggests that a child's current level of fluid intelligence (and not age) determines task performance. We suggest that the relationship among goal neglect, complex task instructions, and fluid intelligence is linked to the mental preparation for future events, that is, mentally compiling verbal instructions into a set of activated goal representations in working memory that represent what is to be done and under what circumstances.