Critical Brain Development in Toddlers at 16 Months

Summary: Researchers found that 16-month-old toddlers engage more brain regions to develop cognitive skills like inhibitory control. Using functional near-infrared spectroscopy (fNIRS), the study showed increased brain activity in the prefrontal and parietal cortex.

Despite no observable improvement in skills, significant brain changes were noted between 10 and 16 months. This highlights 16 months as a crucial period for developing the ability to follow instructions and control impulses.

Key Facts:

  1. Enhanced Brain Activity: 16-month-olds use more brain regions for cognitive tasks.
  2. Inhibitory Control: Key skill involving impulse control shows brain changes despite no performance improvement.
  3. Critical Period: 16 months is pivotal for brain development and cognitive skills.

Source: University of Bristol

Toddlers engage more regions of their brains around 16-months to help them develop important cognitive skills, enabling them to follow simple instructions and control impulses.

Findings from the study, led by the Universities of Bristol and Oxford, and published in Imaging Neuroscience, suggests 16 months is a critical period for brain development.

A child’s first two years of life are crucial for developing cognitive skills, particularly executive functions that help adjust thoughts, actions, and behaviors for everyday life.

This shows a toddler.
The results reveal that 16 months is a critical period for brain development, enabling toddlers to follow simple instructions and control impulses. Credit: Neuroscience News

Inhibitory control is one important executive function. This particular skill allows individuals to stop themselves from doing something out of impulse, habit or temptation. It’s already known that inhibitory control begins to develop in infancy and grows into early childhood. However, until now, the brain mechanisms involved in its development were unclear.

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

The study was led by Abigail Fiske, postdoctoral researcher at the University of Oxford, and Karla Holmboe, Associate Professor in Developmental Science at the University of Bristol’s School of Psychological Science.

They said, “These results are exciting because they shed new light on substantial changes in the brain across the transition from infancy to toddlerhood, despite there being no improvement in inhibitory control skills over this period.

“Our findings contribute new knowledge about the role of brain areas in early development and could help future research piece together a picture of how an important cognitive skill (inhibitory control), and the brain areas involved, develop from infancy to adulthood.”

Fiske and Holmboe added, “What are the implications for parents and caregivers? It’s often noticed that toddlers frequently struggle to stop themselves from doing something. In our study we have shown that lots of changes are happening in toddlers’ brains, and we think that these changes support them in learning this important new skill.”

About this cognitive development research news

Author: Abigail Fiske
Source: University of Bristol
Contact: Abigail Fiske – University of Bristol
Image: The image is credited to Neuroscience News

Original Research: Open access.
The neural correlates of response inhibition across the transition from infancy to toddlerhood: An fNIRS study” by Abigail Fiske et al. Imaging Neuroscience


The neural correlates of response inhibition across the transition from infancy to toddlerhood: An fNIRS study

The transition from late infancy into toddlerhood represents a fundamental period in early development. During this time, the prefrontal cortex (PFC) is undergoing structural and functional maturation processes that parallel the emergence and improvement of executive function skills, such as inhibitory control.

Despite the importance of this developmental period, relatively little is known about the emergence and development of response inhibition, a form of inhibitory control, and the associated neural substrates across this key transition.

Using functional near-infrared spectroscopy (fNIRS), an optical imaging technique suitable for imaging the developing brain, and an age-appropriate response inhibition task, we investigated the brain regions associated with response inhibition in 16-month-old toddlers.

This pre-registered study extends our previous work with 10-month-old infants (Fiske et al., 2022) as it follows the same cohort of participants, now at 16 months of age. Whilst our previous work demonstrated that 10-month-old infants recruited right-lateralised regions of the PFC and parietal cortex when inhibition was required, the current study suggests that by 16 months, toddlers recruit the left superior parietal gyrus, the right inferior frontal gyrus, and bilateral regions of the dorsolateral PFC and orbital frontal cortex.

Although there was no longitudinal change in response inhibition performance, more widespread, bilateral regions of the PFC were recruited during response inhibition at 16 months compared with 10 months. We acknowledge the need for replication of these results.

Nevertheless, our findings suggest that the transition from infancy to toddlerhood may constitute an important period of reorganisation of the PFC that might support the development of early inhibitory control processes.

Join our Newsletter
I agree to have my personal information transferred to AWeber for Neuroscience Newsletter ( more information )
Sign up to receive our recent neuroscience headlines and summaries sent to your email once a day, totally free.
We hate spam and only use your email to contact you about newsletters. You can cancel your subscription any time.