An Early Start to Schooling Improves Visual Working Memory Performance

• In Event: Causal Impacts of Schooling on Children’s Cognitive and Brain Development

Abstract

School cut-off designs are effective ways to investigate the impact of schooling on cognitive function because they compare performance in two groups of children who are similar in age but enrolled in different school years. Previous work employing such designs have observed a positive effect of numeracy and literacy skills. However, it remains unclear whether an early start to schooling has benefits that extend to processes subserving cognitive control such as visual working memory. In the current study, we predicted that children who had an early start to schooling (FGs) would show improved VWM performance and associated changes in brain function compared to children who had been deferred in kindergarten for an extra year (KGs). We also hypothesize that this improvement in VWM performance will be associated with improvements in academic achievement. The study had two time-points: (1) T1: both groups were in kindergarten (FGs: N=40; Age = 53.7±1.4 months and KGs: N=40; Age = 53.3±1.2 months) and (2) T2: one group of children had finished first grade (FGs: Age = 65.7±1.1 months and KGs: Age = 65.3±1 months). All data was collected from children in their homes in Scotland. A color change detection task was used to test visual working memory performance with loads of 1,2 and 3 items at T1 and loads 2,3 and 4 at T2. Accuracy was obtained as a measure of VWM performance. A portable functional near-infrared spectroscopy machine was used to measure brain activation from the frontal and parietal cortices as children engaged on the VWM task. Novel image reconstruction methods were used to obtain voxel-wise measures of brain activation for each condition. Further, all children also completed the vocabulary subset of the Wechsler Preschool and Primary Scale of Intelligence to assess word knowledge and a numeracy screener to assess basic numeracy skills – these measures were used for assessing academic achievements. Structural equation modelling was used to represent, estimate and test relationships between variables of interest. FGs showed an improvement in VWM performance from T1 to T2, whereas KGs showed no change in performance. FGs also showed an increase in activation from T1 to T2 in a cluster in the left middle frontal gyrus whereas KGs did not show any significant change across the time points. Both FGs and KGs showed a significant increase in vocabulary scores between T1 and T2. However, this improvement in FGs was significantly greater than the improvement in KGs. Further, both groups did not differ at baseline for overall accuracy, brain activation and vocabulary scores. There was no effect of group on scores from the numeracy screener. Finally, FGs who had better VWM performance at T1 showed a greater improvement in vocabulary scores across the two time-points whereas this association was not observed in KGs. Our findings show that an early start to schooling affords significant improvements to visual working memory processing, which can then have a positive effect on academic achievements, as observed through an improvement of vocabulary knowledge.

Authors

• Sobanawartiny Wijeakumar, University of Nottingham
  Presenting Author

• Courtney McKay, University of Stirling
  Non-Presenting Author

• Eva Rafetseder, University of Stirling
  Non-Presenting Author

• Yee Lee Shing, Goethe University Frankfurt
  Non-Presenting Author