Infant learning and cognitive development

Child development is a gradual unfolding of biologically determined characteristics and traits that arise as the child learns from experience. Key factors that influence child development and learning – and eventual brain maturation – include genetics, parental behaviours, social-cultural environment, stimulation and parenting style, and nutrition.^1,2
 

Synaptogenesis, myelination and the connected brain

Postnatally, the brain grows both in size and complexity. Billions of neurons are formed and create a brain network that facilitate fast and efficient information processing that underlies and regulates how we think, feel, and act.³

Brain connections are forged through synaptogenesis, i.e. the formation of synapses across which signals are transmitted from one neuron to another, which is critical for information processing.^4,5

Myelination – the process in which neuronal axons are wrapped in a lipid-rich sheath – ensures fast, efficient and synchronized communication between neurons and thus facilitates information processing.^6,7 It develops in a specific trajectory, beginning at around the third trimester of gestation, accelerating during the late fetal and early postnatal life, and slowing down as the child reaches 2 years of age. Studies suggest a direct link between myelination and brain maturation and cognitive development, i.e. white matter development in specific regions of the brain is correlated with the onset of developmental milestones.^8,9 Myelination has been correlated with the development of cognitive skills, e.g. general cognitive ability,8 language and reading,¹⁰ working memory,⁹ processing speed¹¹ and sensory reactivity.¹²
 

Nutrition impacts myelination

A study that compared the myelin trajectories and cognitive development of exclusively breastfed and formula-fed infants for at least the first 3 months of life showed that exclusively breastfed infants had significantly higher myelination as well as higher cognitive scores compared with exclusively formula-fed infants.¹³ Retrospective analyses of individual nutrients showed significant associations between myelin content and DHA, ARA, folic acid, iron, phosphatidylcholine and sphingomyelin.

Sphingomyelin is particularly rich in the myelin sheath, which is important for supporting myelin integrity and function,¹⁴ and axonal maturation.¹⁵ Higher levels of dietary sphingomyelin in the first three months of life has been significantly associated with verbal development in the first two years of life, as well as higher levels of myelin content at 12-24 months (Figure 2), delayed onset, and/or more prolonged rates of myelination in different brain areas (Figure 3).¹⁶  These findings suggest early life provision of dietary sphingomyelin may contribute to learning and development, through its role in supporting myelination.
 

Figure 2. White matter myelination trajectories of children who received infant formula with high sphingomyelin content (71 mg/L) or a lower sphingomyelin content (28 mg/L).¹⁶
 

Figure 3. Brain regions (colored areas) with a significant relationship between sphingomyelin content and brain myelin water fraction (MWF) in children 12–24 months of age.¹⁶

In summary, myelination may be influenced by nutritional factors, including adequate phospholipid and sphingomyelin during early life. Nutrition therefore contributes to learning and development through its effects on the brain structure and function that underpin how we think, act, feel and learn.

Reference

1. American Psychological Association. Research in Brain Function and Learning. Available at: https://www.apa.org/education/k12/brain-function. Accessed Feb 2021.
2. The Visual Learning Centers of America. The Connection Between Vision & Learning. Available at: https://www.vlca.com/visionlearning.php. Accessed Feb 2021.
3. Harvard University Center of the Developing Child. Brain architecture. Available at: https://developingchild.harvard.edu/science/key-concepts/brain-architecture/. Accessed Feb 2021.
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6. Snaidero N, Simons M. J Cell Sci. 2014 Jul 15;127(Pt 14):2999-3004.
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14. Ledesma MD, et al. EMBO J. 1999 Apr 1;18(7):1761-71.
15. Cilla A, et al. Crit Rev Food Sci Nutr. 2016 Aug 17;56(11):1880-92.
16. Schneider N, et al. eNeuro. 2019 Aug 6;6(4):ENEURO.0421-18.2019.