Differences in brain morphology and working memory capacity across childhood

Abstract

Working memory (WM) skills are closely associated with learning progress in key areas such as reading and mathematics across childhood. As yet, however, little is known about how the brain systems underpinning WM develop over this critical developmental period. The current study investigated whether and how structural brain correlates of components of the working memory system change over development. Verbal and visuospatial short‐term and working memory were assessed in 153 children between 5.58 and 15.92 years, and latent components of the working memory system were derived. Fractional anisotropy and cortical thickness maps were derived from T1‐weighted and diffusion‐weighted MRI and processed using eigenanatomy decomposition. There was a greater involvement of the corpus callosum and posterior temporal white matter in younger children for performance associated with the executive part of the working memory system. For older children, this was more closely linked with the thickness of the occipitotemporal cortex. These findings suggest that increasing specialization leads to shifts in the contribution of neural substrates over childhood, moving from an early dependence on a distributed system supported by long‐range connections to later reliance on specialized local circuitry. Our findings demonstrate that despite the component factor structure being stable across childhood, the underlying brain systems supporting working memory change. Taking the age of the child into account, and not just their overall score, is likely to be critical for understanding the nature of the limitations on their working memory capacity.

Neonatal imitation: Temporal characteristics in imitative response patterns

“…Furthermore, we hypothesize that this system is mainly governed subcortically early in development. It also seems possible that early imitation processes rely more on distributed networks while later imitation will rely on more specialized circuitry as recently found for the development of working memory (Bathelt, Gathercole, Johnson, & Astle, 2017). Associative learning seems less plausible as an explanation of imitation in newborns, although it probably comes into play as a child's imitative ability or motivation to imitate develops over time.…”

Early childhood development of white matter fiber density and morphology

“…Early childhood is a period of profound maturation of cognitive and behavioral skills, including attention (Breckenridge et al, 2013;Mullane et al, 2016), working memory (Burnett Heyes et al, 2012), reading (Ferretti et al, 2008), math (Garon-Carrier et al, 2018), and self-regulation (Montroy et al, 2016). These skills have been linked to white matter properties during childhood (Bathelt et al, 2018;Jolles et al, 2016;Klarborg et al, 2013;Qiu et al, 2008;Van Eimeren et al, 2008), though the relationship between cognitive-behavioral skills and axonal density and fiber bundle size remains largely unexplored. One study has shown an association between FD and inattentive/internalizing behavior in typically developing children (Genc et al, 2019), while we have previously reported an association between FD and social skills in adolescents and young adults with Autism Spectrum Disorder .…”

“…Maturation of these essential cognitive-behavioral skills is believed to be related to white matter growth in the brain (Bathelt et al, 2018;Jolles et al, 2016;Klarborg et al, 2013;Qiu et al, 2008;Van Eimeren et al, 2008), though developmental trajectories of white matter maturation and the biological underpinnings of these changes remain poorly understood. The reason for this is two-fold.…”

Maturation and interhemispheric asymmetry in neurite density and orientation dispersion in early childhood

“…Axonal fiber bundles (also referred to as “white matter tracts”) form the structural framework of the brain, facilitating rapid communication across brain networks and enabling distributed cognitive processing. Developmental changes in white matter properties are unsurprisingly linked to cognitive maturation (Bathelt et al, 2018; Jolles et al, 2016; Klarborg et al, 2013; Qiu et al, 2008; Van Eimeren et al, 2008), though these changes are understudied during early childhood, and trajectories for specific structural features are unclear.…”