Childhood stimulation key to brain development, says study
20-year study shows educational interaction with parents around the age of four aids a child's development of 'grey matter' in teens
An early childhood surrounded by books and educational toys will leave positive fingerprints on a person's brain well into their late teens, a 20-year research study has shown.
Scientists found that the more mental stimulation a child gets around the age of four, the more developed the parts of their brains dedicated to language and cognition will be in the decades ahead.
It is known that childhood experience influences brain development but the only evidence scientists have had for this has usually come from extreme cases such as children who had been abused or suffered trauma.
Martha Farah, director of the centre for neuroscience and society at the University of Pennsylvania, who led the latest study, wanted to find out how a normal range of experiences in childhood might influence brain development.
Farah took data from surveys of home life and brain scans of 64 participants over 20 years. Her results were presented on Saturday at the annual meeting of the Society for Neuroscience in New Orleans.
They showed that cognitive stimulation from parents at the age of four was the key factor in predicting the development of several parts of the cortex - the layer of grey matter on the outside of the brain - 15 years later.
The participants had been tracked since they were four years old.
Researchers had visited their homes and recorded details about their lives to measure cognitive stimulation, such as the number of children's books they had, whether they had toys that taught them about colours, numbers or letters, or whether they played with real or toy musical instruments.
They also scored the participants on "parental nurturance" - how much warmth, support or care the child got from the parent.
The researchers carried out the same surveys when the children were eight years old, and when they were between 17 and 19, they had their brains scanned.
Farah's results showed that the development of the cortex in the late teens was closely correlated with a child's cognitive stimulation at the age of four.
All other factors - including parental nurturance at all ages and cognitive stimulation at age eight - had no effect.
Farah said her results were evidence for the existence of a sensitive period, early in a person's life, that determined the optimal development of the cortex. "It really does support the idea that those early years are especially influential," she said.
Around the time the participants had their brains scanned in their late teens, they were also given language tests and, Farah said, the thinner their cortex, the better their language comprehension.
Andrea Danese, a clinical lecturer in child and adolescent psychiatry at the Institute of Psychiatry, King's College London, said: "Parents may not be around when their teenage children are faced with important choices about choosing peers, experimenting with drugs, engaging in sexual relationships, or staying in education.
"Yet parents can lay the foundations for their teenage children to take good decisions, for example by promoting their ability to retain and elaborate information, or to balance the desire for immediate reward with the one for greater, long-term goals since a young age."