Understanding the neural basis of inhibitory control in infancy using functional near-infrared spectroscopy

• In Event: A Neuroscientific Perspective on Key Transitions in the Development of Cognitive Control

Abstract

Inhibitory control, a core executive function skill, develops rapidly across the first three years of life. Although evidence supports the emergence of inhibitory control in the first year, little is understood about its development from late infancy and across toddlerhood. Even less is known about the neural mechanisms that underpin this development – primarily due to a lack of age-appropriate tasks and access to neuroimaging methods suitable for the toddler population. With the introduction of functional near-infrared spectroscopy (fNIRS) - an optical imaging technique that measures haemoglobin concentration changes in the cortex - researchers have been able to localise functional neural activation in the brains of infants and toddlers.

Our first study aimed to uncover the neural underpinnings of inhibitory control in 10-month-old infants (N = 135; 70% White British, middle-to-high socio-economic status) by employing fNIRS alongside a novel touchscreen task that measures response inhibition (The Early Childhood Inhibitory Touchscreen Task (ECITT); Holmboe et al. 2021). Based on research that used the ECITT with similar infant populations (Hendry et al. 2021), we hypothesised that infants would be significantly more accurate on prepotent trials (no inhibitory demand) than on trials where inhibition was required (inhibitory trials). Since previous studies with older children (Mehnert et al. 2013) and adults (Aron et al. 2014) have highlighted the involvement of the prefrontal cortex and parietal lobe in inhibition, our fNIRS probe was designed to hold an array of 32 optical sensors that bilaterally covered the prefrontal cortex and the intraparietal sulcus. Due to the lack of existing fNIRS studies that used manual response-based tasks with developmental populations, we made no hypotheses about which specific brain areas within these broader regions would be associated with response inhibition in infancy.

Behavioural results revealed that 10-month-old infants were significantly more accurate on prepotent trials (no inhibitory demand) than on inhibitory demanding trials; F (1, 119) = 161.411, p < .001, ηp2 = 0.576. We found that when inhibition was required, the right prefrontal and parietal cortices were more activated than when there was no inhibitory demand. This demonstrates that inhibitory control in infants as young as 10 months of age is supported by similar brain areas as in older children and adults. This study has lowered the age-boundary for localising the neural substrates of response inhibition to the first year of life.

Our second study will examine this cohort of infants at 16-months of age (N ~ 94) using the same experimental paradigm to investigate the development and neural underpinnings of inhibitory control early in the second year of life. Additionally, with this longitudinal dataset, we will examine the developmental trajectory and neural correlates of inhibitory control from infancy (10-months) to toddlerhood (16-months).

Authors

• Abigail Fiske, University of Oxford
  Presenting Author

• Carina De Klerk

• Katie Y. K. Lui

• Liam Collins-Jones, UCL

• Alexandra Hendry, University of Oxford

• Isobel Greenhalgh

• Anna Hall

• Gaia Scerif, University of Oxford

• Henrik Dversgdal

• Karla Holmboe, University of Oxford