Intra-individual variability in task performance after cognitive training is associated with long-term outcomes in children

Abstract

The benefits and mechanistic effects of working memory training in children are the subject of much research and debate. The cumulative evidence indicates that training can alter brain structure and function in the short term and have lasting effects on behaviour. We show that five weeks of working memory training led to greater activity in prefrontal and striatal brain regions, better accuracy, and reduced intra-individual variability in response times. The reduction in intra-individual variability can be explained by changes to the evidence accumulation rates and thresholds in a sequential sampling decision model. Critically, intra-individual variability was more closely associated with academic skills and mental health 6-12 months after the end of training than task accuracy. These results indicate that intra-individual variability may be a useful way to quantify the immediate impact of cognitive training interventions and predict the future emergence of academic and socioemotional skills.

An Ecological Systems Perspective on Individual Differences in Children’s Performance on Measures of Executive Function

“…Reaction time is one intra-individual factor that contributes to inter-individual differences in performance on cognitive-behavioral measures of EF (Blair et al, 2005); some children are simply able to respond more quickly than others to the requests for responses imposed by measures of EF. Indeed, one recent study reported that inter-individual differences in intra-individual variability of reaction time on an EF task was a stronger predictor of individual differences in academic outcomes than differences in task accuracy (Cubillo et al, 2022).…”