The Adaptive Brain Across Development: Age Related Changes in Cortical Adaptation

How does the functionality of the cortex change from infancy to adulthood to support the developmental cognitive shift from learners to performers? Cortical adaptation is a simple neural mechanism which plays a key role in learning and memory encoding, but little is known about how it develops across the lifespan. Both infants and adults have been found to respond differently to repeating audio and visual stimuli, suggesting differences in cortical adaptation throughout development. However, studies typically approach these populations through different paradigms and interpret the results in terms of different cognitive models. To overcome these issues, we implemented an identical paradigm across all age groups to examine cortical adaptation and its developmental trajectory. We used functional near infra-red spectroscopy (fNIRS) to chart how different regions in the infant, child and adult brain respond to repeating audiovisual stimuli at varying inter-stimulus intervals (ISIs), using cortical adaptation as a proxy for implicit memory dynamics. We found faster recovery from adaptation in infants compared to children and adults. Specifically, there was an interaction between stimulus presentation rate and age in the right temporal, left parietal and occipital cortical areas. There was also a developmental progression in functional connectivity, with infants displaying significantly lower correlations between regions of interest than children and adults. Taken together, we suggest these findings may reflect the developmental trajectory of cortical adaptation from a learning system optimized for maximal information intake and minimal filtering of stimuli to a specialized integrative system that efficiently filters and adapts to information. HighlightsO_LICortical adaptation is a fundamental mechanism involved in memory and learning, but not much is known about how it develops throughout the lifespan. C_LIO_LIAn identical fNIRS paradigm across 3 different age groups reveals significant differences in cortical adaptation between infants, children and adults. C_LIO_LIFunctional connectivity revealed foundational connections present from infancy, growing stronger and into a specialized adaptation system with age. C_LI These findings suggest a developmental transition from a system optimized for maximal information intake to a specialized learning system, capable of filtering redundant information.