Publications
You can also find my articles on my Google Scholar profile.
Published in Progress in Neurobiology, 2024
The development and refinement of neuronal circuitry allow for stabilized and efficient neural recruitment, supporting adult-like behavioral performance. During adolescence, the maturation of PFC is proposed to be a critical period (CP) for executive function, driven by a break in balance between glutamatergic excitation and GABAergic inhibition (E/I) neurotransmission. During CPs, cortical circuitry fine-tunes to improve information processing and reliable responses to stimuli, shifting from spontaneous to evoked activity, enhancing the SNR, and promoting neural synchronization. Our findings reveal age-related shifts in glutamate and GABA balance, which enhance cortical signal-to-noise ratio (SNR) and neural synchronization during cognitive tasks. These changes align with improvements in working memory, highlighting critical period plasticity in the PFC. This work sheds light on how stabilized circuitry supports efficient neural recruitment for adult-like behavior.
Recommended citation: McKeon, S.D. et al. Prefrontal Excitation/ Inhibition Balance Supports Adolescent Enhancements in Circuit Signal to Noise Ratio. Progress in Neurobiology. 2024. https://doi.org/10.1016/j.pneurobio.2024.102695. https://www.sciencedirect.com/science/article/pii/S030100822400131X#ab0010
Published in Developmental Cognitive Neuroscience, 2024
Adolescence has been hypothesized to be a critical period for the development of human association cortex and higher-order cognition. A defining feature of critical period development is a shift in the excitation: inhibition (E/I) balance of neural circuitry, however how changes in E/I may enhance cortical circuit function to support maturational improvements in cognitive capacities is not known. Harnessing ultra-high field 7 T MR spectroscopy and EEG in a large, longitudinal cohort of youth (N = 164, ages 10–32 years old, 347 neuroimaging sessions), we delineate biologically specific associations between age-related changes in excitatory glutamate and inhibitory GABA neurotransmitters and EEG-derived measures of aperiodic neural activity reflective of E/I balance in prefrontal association cortex.
Recommended citation: McKeon, S. D. et al. Aperiodic EEG and 7T MRSI evidence for maturation of E/I balance supporting the development of working memory through adolescence. Developmental Cognitive Neuroscience. (2024) doi: https://doi.org/10.1101/2023.09.06.556453 https://www.sciencedirect.com/science/article/pii/S1878929324000343
Published in Developmental Cognitive Neuroscience, 2024
Recently, politicians and legislative bodies have cited neurodevelopmental literature to argue that brain immaturity undermines decision-making regarding gender-affirming care (GAC) in youth. Here, we review this literature as it applies to adolescents’ ability to make decisions regarding GAC.
Recommended citation: Orma Ravindranath, Maria I. Perica, Ashley C. Parr, Amar Ojha, Shane D. McKeon, Gerald Montano, Naomi Ullendorf, Beatriz Luna, E. Kale Edmiston. Adolescent neurocognitive development and decision-making abilities regarding gender-affirming care. Developmental Cognitive Neuroscience. 2024. 101351. ISSN 1878-9293. https://www.sciencedirect.com/science/article/pii/S1878929324000124
Published in NeuroImage, 2023
Adolescence is a stage of development characterized by neurodevelopmental specialization of cognitive processes. In particular, working memory continues to improve through adolescence, with increases in response accuracy and decreases in response latency continuing well into the twenties. Human electroencephalogram (EEG) studies indicate that gamma oscillations (35–65 Hz) during the working memory delay period support the maintenance of mnemonic information guiding subsequent goal-driven behavior, which decrease in power with development. Importantly, recent electrophysiological studies have shown that gamma events, more so than sustained activity, may underlie working memory maintenance during the delay period. However, developmental differences in gamma events during working memory have not been studied.
Recommended citation: McKeon, S. D. et al. Age-related differences in transient gamma band activity during working memory maintenance through adolescence. NeuroImage 120112 (2023) doi:10.1016/j.neuroimage.2023.120112 https://www.sciencedirect.com/science/article/pii/S1053811923002586
