Ipsilesional functional recruitment within lower mu band in children with unilateral cerebral palsy, an event-related desynchronization study.

Cerebral palsy (CP) is a group of non-progressive developmental movement disorders inducing a strong brain reorganization in primary and secondary motor areas. Nevertheless, few studies have been dedicated to quantify brain pattern changes and correlate them with motor characteristics in CP children. In this context, it is very important to identify feasible and complementary tools able to enrich the description of motor impairments by considering their neural correlates. To this aim, we recorded the electroencephalographic activity and the corresponding event-related desynchronization (ERD) of a group of mild-to-moderate affected unilateral CP children while performing unilateral reach-to-grasp movements with both their paretic and non-paretic arms. During paretic arm movement execution, we found a reduced ERD in the upper µ band (10-12.5 Hz) over central electrodes, preceded by an increased fronto-central ERD in the lower µ band (7.5-10 Hz) during movement preparation. These changes positively correlated, respectively, with the Modified House Classification scale and the Manual Ability Classification System. The fronto-central activation likely represents an ipsilesional plastic compensatory reorganization, confirming that in not-severely affected CP, the lesioned hemisphere is able to compensate part of the damage effects. These results highlight the importance of analyzing different sub-bands within the classical mu band and suggest that in similar CP population, the lesioned hemisphere should be the target of specific intensive rehabilitation programs.

How preschool executive functioning predicts several aspects of math achievement in Grades 1 and 3: A longitudinal study.

This longitudinal study analyzes whether selected components of executive function (EF) measured during the preschool period predict several indices of math achievement in primary school. Six EF measures were assessed in a sample of 5-year-old children (N = 175). The math achievement of the same children was then tested in Grades 1 and 3 using both a composite math score and three single indices of written calculation, arithmetical facts, and problem solving. Using previous results obtained from the same sample of children, a confirmatory factor analysis examining the latent EF structure in kindergarten indicated that a two-factor model provided the best fit for the data. In this model, inhibition and working memory (WM)-flexibility were separate dimensions. A full structural equation model was then used to test the hypothesis that math achievement (the composite math score and single math scores) in Grades 1 and 3 could be explained by the two EF components comprising the kindergarten model. The results indicate that the WM-flexibility component measured during the preschool period substantially predicts mathematical achievement, especially in Grade 3. The math composite scores were predicted by the WM-flexibility factor at both grade levels. In Grade 3, both problem solving and arithmetical facts were predicted by the WM-flexibility component. The results empirically support interventions that target EF as an important component of early childhood mathematics education.

Working memory control deficit in kindergarten ADHD children.

The present study tests the hypothesis that a working memory deficit is also found in children with attention deficit/hyperactivity disorder (ADHD) symptoms as young as 5 and is related to the control of interfering information. One group of 23 kindergarten children identified by the presence of ADHD symptoms and one group of 23 children matched for gender, age, and socioeconomic status were administered a visuospatial working memory task that required the selective recall of information. Children with ADHD symptoms performed more poorly than controls and were affected to a particularly high extent by intrusion errors (i.e., recalling of information initially encoded but that needed to be consequently suppressed during the task).