Genetics and Learning: How the Genes Influence Educational Attainment

The brain is the organ of thought. The word thought is defined as the act of thinking about or considering something: an idea or opinion, or a set of ideas about a particular subject. It implicitly includes the processes of learning. Mental functions, including most if not all aspects of human behavior, such as those related to learning, arise from the activity of the brain. Neural connections that generate and support mental functions are formed throughout life, which enables lifelong learning of new concepts and skills. Both brain formation and function, as well as neural plasticity, are influenced by the activity of a variety of genes and also by epigenetic modifications, which contribute to the regulation of gene expression by adapting it to environmental conditions. In this review, aimed especially at education professionals, I discuss the genetic and epigenetic contributions to mental aspects related to learning processes in terms of heritability. I will argue that, despite most if not all aspects related to learning having a clear genetic background, innate abilities can be enhanced or diminished through educational processes. Thus, the importance of education, in the context of the inheritability of learning processes, will be discussed. The conclusion I draw is that, despite the relatively high genetic heritability shown in most brain processes associated with learning, educational practices are a key contributor to student development, allowing genetically based skills to be enhanced or alternatively diminished. Therefore one of the main goals of education in a changing an uncertain world should be to form adaptable and versatile people who can, and want to, make the most of their capabilities. Thus, knowledge derived from genetics and epigenetics, as well as from neuroscience, should be used to enhance education professionals’ understanding of the biological origins of differences in mental capabilities, thereby empowering them with the possibility to adopt more respectful and flexible educational practices to attain the goal mentioned above.

Long-term developmental effects of withholding parenteral nutrition for 1 week in the paediatric intensive care unit: a 2-year follow-up of the PEPaNIC international, randomised, controlled trial

BACKGROUND

The paediatric early versus late parenteral nutrition in critical illness (PEPaNIC) multicentre, randomised, controlled trial showed that, compared with early parenteral nutrition, withholding supplemental parenteral nutrition for 1 week in the paediatric intensive care unit (PICU; late parenteral nutrition) reduced infections and accelerated recovery from critical illness in children. We aimed to investigate the long-term impact on physical and neurocognitive development of early versus late parenteral nutrition.

METHODS

In this preplanned 2-year follow-up study, all patients included in the PEPaNIC trial (which was done in University Hospitals Leuven, Belgium; Erasmus Medical Centre-Sophia Children's Hospital, Rotterdam, Netherlands; and Stollery Children's Hospital, Edmonton, AB, Canada) were approached for possible assessment of physical and neurocognitive development compared with healthy children who were matched for age and sex, and who had never been admitted to a neonatal ICU or a PICU. Assessed outcomes comprised anthropometric data; health status; parent-reported or caregiver-reported executive functions and emotional and behavioural problems; and tests for intelligence, visual-motor integration, alertness, motor coordination, inhibitory control, cognitive flexibility, and memory. To address partial responses among the children tested, we did multiple data imputation by chained equations before univariable and multivariable linear and logistic regression analyses adjusted for risk factors. This trial is registered with ClinicalTrials.gov, number NCT01536275.

FINDINGS

At the 2-year follow-up, 60 (8%) of 717 children who received late parenteral nutrition and 63 (9%) of 723 children who received early parenteral nutrition had died (p=0·81). 68 (9%) of 717 children who received late and 91 (13%) of 723 children who received early parenteral nutrition were too disabled for neurocognitive assessment (p=0·059), and 786 patients (395 assigned to late and 391 assigned to early parenteral nutrition) consented for testing. 786 patients and 405 healthy control children underwent long-term outcome testing between Aug 4, 2014, and Jan 19, 2018, and were included in the imputation model for subsequent multivariable analyses. Late parenteral nutrition did not adversely affect anthropometric data, health status, or neurological functioning, and improved parent-reported or caregiver-reported executive functioning (late vs early parenteral nutrition β estimate -2·258, 95% CI -4·012 to -0·504; p=0·011), more specifically inhibition (-3·422, -5·171 to -1·673; p=0·0001), working memory (-2·016, -3·761 to -0·270; p=0·023), and meta-cognition (-1·957, -3·694 to -0·220; p=0·027). Externalising behavioural problems (β estimate -1·715, 95% CI -3·325 to -0·106; p=0·036) and visual-motor integration (0·468, 0·087 to 0·850; p=0·016) were also improved in the late parenteral nutrition group compared with the early parenteral nutrition group. After Bonferroni correction for multiple comparisons, the effect on inhibitory control remained significant (p=0·0001).

INTERPRETATION

Withholding early parenteral nutrition for 1 week in the PICU did not negatively affect survival, anthropometrics, health status, and neurocognitive development, and improved inhibitory control 2 years after PICU admission.

FUNDING

European Research Council Advanced Grant, Methusalem programme provided by the Flemish Government, Flemish Agency for Innovation by Science and Technology (IWT), Research Foundation Flanders (FWO), Sophia Children's Hospital Foundation (SSWO), Stichting Agis Zorginnovatie, Erasmus Trustfonds, and European Society for Parenteral and Enteral Nutrition (ESPEN) research grant.