Researchers at the Oxford University Baby Lab and Bristol University Baby Lab sought to examine the brain activity of 16-month-old toddlers by using a child-friendly brain imaging technique called functional near-infrared spectroscopy (fNIRS). They gave 103 toddlers a simple touchscreen task to complete that would require them to use inhibitory control skills.  This experiment allowed researchers to see which brain areas were activated when inhibitory control skills were used. The study replicated a previous experiment with the same group of children when they were 10 months old.

The earlier study found that 10-month-olds used the right side of their prefrontal and parietal cortex for inhibitory control. In this latest study, the team show that by 16 months, toddlers use the left parietal cortex and both sides of the prefrontal cortex more extensively.

Interestingly, these brain changes occur despite how well children performed in the task staying the same between 10 and 16 months. Testing the same group of children at 10- and 16-months of age, the team found, as babies grow into toddlers, they continue to struggle to stop themselves from doing a habitual action, but the brain activation associated with this skill changes dramatically. This indicates that 16-month-old toddlers are using more areas of the brain than at 10 months even if their observable skills remained the same.

The results reveals that 16 months is a critical period for brain development, enabling toddlers to follow simple instructions and control impulses.

Read the full University of Bristol news item

Paper: ‘The neural correlates of response inhibition across the transition from infancy to toddlerhood: An fNIRS study’ by A Fiske, K Holmboe et al. in Imaging Neuroscience