Nanogirl Dr Michelle Dickinson: Research shows impact of poverty on children's brain development

In a test, children from low income families showed weaker brain activity and a higher susceptibility to being distracted. Photo / Getty Images

Statistics NZ this week put out data showing that 254,000 or 23 per cent of children in New Zealand are living in poverty. Child poverty is already known to be associated with negative health and educational outcomes. Now a study has shown it also has a negative effect on a child's brain development from a very early age.

Child poverty in New Zealand is classed as children living in homes with less than 50 per cent of the median income, factoring in the percentage of household income spent on housing costs and measuring perspectives on material hardship.

This involves asking adults in the home to discuss if they can afford to pay utility bills on time and if they have items at home such as two good pairs of shoes. Data shows that childhood poverty is increasing and housing costs seem to have a significant influence.

Previous research has shown that growing up in poverty can significantly impact the brain development of children. To understand this further, a new study published this week looked at brain function in children aged 4 months to 4 years. The researchers wanted to see if poverty had any effect on early brain development - a possible factor for many children in poverty failing to reach their potential.

The researchers used a functional near infrared spectroscopy (fNIRS) device which shines light into cortical tissue through a special cap worn on the child's head. The device is able to measure changes such as blood oxygenation and blood volume in the front part of the brain while the child is given tasks to complete.

Once connected to the device, the children were asked to take part in a visual test which involved blinking displays of coloured squares. Visual working memory is an easy marker for early cognitive development and allows children with no reading or writing ability to be tested and compared.

The activity measured how well the children could remember the colours of the squares and if they had noticed that one side of the square always changed colour while the other stayed the same throughout the test.

After the test, other information about the child including parental education, religion, number of children in the family and economic status and income was also collected.

The results showed children from low income families showed weaker brain activity and a higher susceptibility to being distracted. Through the blood flow data they were able to trace this back to poorer distractor suppression in the left frontal cortex which is the part of the brain involved in working memory.

The children who performed the worst on the test not only came from low income homes but also had mothers with low levels of formal education.

The research, published in the journal Developmental Science, suggests that increasing household income is only one factor when it comes to improving outcomes for children growing up in poverty.

Based on this, and knowledge around brain plasticity in children, more resources with measurable outcomes need to be spent on early childhood education programmes that are designed to boost and strengthen brain health for our most at-risk children.

Mentoring programmes with adults with formal education qualifications could also help to socialise at-risk children with positive role models to help to break the cycle of inter-generational poverty through poor educational achievement.

This Government is committed to reducing child poverty and improving the wellbeing of all children and young people. Perhaps it's time to look at new research for how we might use scientific evidence to do this.