Rapid infant prefrontal cortex development and sensitivity to early environmental experience

Abstract

Over the last fifteen years, the emerging field of developmental cognitive neuroscience has described the relatively late development of prefrontal cortex in children and the relation between gradual structural changes and children’s protracted development of prefrontal-dependent skills. Widespread recognition by the broader scientific community of the extended development of prefrontal cortex has led to the overwhelming perception of prefrontal cortex as a “late developing” region of the brain. However, despite its supposedly protracted development, multiple lines of research have converged to suggest that prefrontal cortex development may be particularly susceptible to individual differences in children’s early environments. Recent studies demonstrate that the impacts of early adverse environments on prefrontal cortex are present very early in development: within the first year of life. This review provides a comprehensive overview of new neuroimaging evidence demonstrating that prefrontal cortex should be characterized as a “rapidly developing” region of the brain, discusses the converging impacts of early adversity on prefrontal circuits, and presents potential mechanisms via which adverse environments shape both concurrent and long-term measures of prefrontal cortex development. Given that environmentally-induced disparities are present in prefrontal cortex development within the first year of life, translational work in intervention and/or prevention science should focus on intervening early in development to take advantages of this early period of rapid prefrontal development and heightened plasticity.

Mental development is associated with cortical connectivity of the ventral and nonspecific thalamus of preterm newborns

“…At term equivalent age, the topography of thalamocortical connections largely resembles that of an adult (Ferradal et al, 2019). Thus, there is overwhelming neuroanatomical evidence for the rapid and late development of the frontal lobe in the human brain (Hodel, 2018), which confers increased vulnerability to adverse environments. Fetal studies have characterized a posterior-to-frontal (sensory-to-higher association) gradient in functional brain development (Jakab et al, 2014;Thomason et al, 2013) TA B L E 4 Intrathalamic specificity of our findings: localization of fibers emerging from the cortically projected thalamocortical significantly correlated with mental development index (details and abbreviations of the thalamic nuclei are given in Table S2) F I G U R E 4 Localization of thalamocortical (TC) connections associated with 2-year outcome: thalamic specificity of our findings.…”

Nurturing the preterm infant brain: leveraging neuroplasticity to improve neurobehavioral outcomes

“…Although less well delineated, this is also evident for other cognitive behaviors. 45 A relative advantage of the human brain's protracted and multifaceted periods of plasticity is that it allows the developing brain to dynamically adapt in response to important environmental cues. There is increasing evidence that positive environmental factors, such as warm and highly responsive caregiving, support healthy brain development.…”

Sensitive periods in executive function development

“…Although the importance of age of adoption on later adaptive functioning has long been recognised [59], these findings are intriguing given the protracted developmental period of EFs and the prefrontal cortex. Recent research points towards extensive reorganisation occurring within the prefrontal cortex in early infancy [60]. Factors occurring within the first few months of life (Figure 1), such as parent-child interactions [61], including scaffolding [20] and interaction contingency [62], or levels of cognitive stimulation [63], may critically impact early brain development and the development of capacities such as attentional regulation, which form the 'building blocks' of EFs, later leading to altered EF development.…”