Biology subjects

McNamee, M.

Publications and source records attributed to McNamee, M..

4 recordsLinked to original sources

bioRxiv2025

Resting state periodic and aperiodic brain oscillations from birth to preschool years: Aperiodic maturity predicts developmental course

The non-invasive assessment of resting-state (RS) neural activity via electrophysiology provides information on brain function and brain health. Our understanding of RS neural activity in older children and adults is limited by our poor understanding of the maturation of RS activity (oscillatory and non- oscillatory) from infancy to preschool ages. The present study used MEG with source imaging and an adapted Dark Room eyes-open task to assess oscillatory and non-oscillatory RS activity. 107 typically developing children 2 to 68 months were enrolled. For the Dark-Room eyes-open task, each child alternated between viewing an Inscapes video without audio for 20s and then resting with their eyes open for 30s in total darkness. This was repeated for 6 cycles. Whole-brain RS activity maps were computed using Minimum Norm Estimates, with RS power spectra divided into estimates of periodic measures (dominant frequency and power) and aperiodic measures (the exponent - slope of the 1/f function; the offset - vertical displacement of the 1/f function). An infant dominant peak was observed more often in the Dark-Room (94% of children) than in the Video-On condition (83% of children). The Dark-Room condition elicited a 36% increase in dominant oscillation activity than the Video-On condition. The maturation of the parietal-occipital periodic dominant frequency increased non-linearly as a function of age. The maturation of aperiodic measures decreased nonlinearly as a function of age, with aperiodic measures as well as their maturation rate differing across the brain. Finally, more mature aperiodic values predicted better adaptive behaviors and daily living skills. Present findings demonstrate that (1) the use of an appropriate Dark-Room eyes-open task provides measures of young child RS periodic activity with excellent SNR, (2) an understanding of the development of infant RS activity is best achieved via obtaining measures in brain source space in order to detect regional differences in aperiodic activity, and (3) a more mature aperiodic value predicts higher developmental behavior scores.

neuroscience↗

bioRxiv2025

Regionally specific resting-state beta neural power predicts brain injury and symptom recovery in adolescents with concussion: a longitudinal study

Mild traumatic brain injury (mTBI) is common in adolescents. Magnetoencephalography (MEG) studies (primarily reporting on adult males) have demonstrated abnormal resting-state (RS) brain activity in mTBI. The present study sought to identify RS abnormalities in male and female adolescents with mTBI (no previous mTBI and no previous DSM-5 diagnosis) identified from an outpatient specialty care concussion program setting as a basis for evaluating potential clinical utility. Visit 1 MEG RS data were obtained from 46 adolescents with mTBI (mean age: 15.4 years, 25 females) within 4 months of a mTBI (mTBI acute to sub-acute period) as well as from 34 typically developing (TD) controls (mean age: 14.8 years; 17 females) identified from the local community. Visit 2 RS data (follow-up [~]4.3 months after Visit 1; mTBI sub-chronic period) were obtained from 36 mTBI (19 females) and 29 TD (14 females) of those participants. Source-space RS neural activity was examined from 4 to 56 Hz. Visit 1 t-tests showed that group differences were largest in the beta range (16-30 Hz; mTBI < TD), with Visit 2 whole-brain linear mixed model (LMM) analyses examining beta-band group differences as a function of Visit. A main effect of Group indicated Visit 1 and 2 beta-band group differences in midline superior frontal gyrus, right temporal pole, and right central sulcus (all mTBI < TD). The group effects were large (Cohens d values 0.75 to 1.31). Of clinical significance in the mTBI group, a decrease in mTBI symptoms from Visit 1 to 2 was associated with an increase in beta power in 4 other brain regions. Present findings suggest that RS beta power has potential as a measure and perhaps as a mechanism of clinical recovery in adolescents with mTBI.

neuroscience↗

bioRxiv2024

The maturation of infant and toddler visual cortex neural activity and associations with fine motor performance

Our understanding of how visual cortex neural processes mature during infancy and toddlerhood is limited. Using magnetoencephalography (MEG), the present study investigated the development of visual evoked responses (VERs) in both cross-sectional and longitudinal samples of infants and toddlers 2 months to 3 years. Brain space analyses focused on N1m and P1m latency, as well as the N1m-to-P1m amplitude. Associations between VER measures and developmental quotient (DQ) scores in the cognitive/visual and fine motor domains were also examined. Results showed a nonlinear decrease in N1m and P1m latency as a function of age, characterized by rapid changes followed by slower progression, with the N1m latency plateauing at 6-7 months and the P1m latency plateauing at 8-9 months. The N1m-to-P1m amplitude also exhibited a non-linear decrease, with strong responses observed in younger infants ([~]2-3 months) and then a gradual decline. Associations between N1m and P1m latency and fine motor DQ scores were observed, suggesting that infants with faster visual processing may be better equipped to perform fine motor tasks. The present findings advance our understanding of the maturation of the infant visual system and highlight the relationship between the maturation of visual system and fine motor skills. HighlightsO_LIThe infant N1m and P1m latency shows a nonlinear decrease. C_LIO_LIN1m latency decreases precede P1m latency decreases. C_LIO_LIN1m-to-P1m amplitude shows a nonlinear decrease, with stronger responses in younger than older infants. C_LIO_LIN1m and P1m latency are associated with fine motor DQ. C_LI

neuroscience↗

bioRxiv2024

Functional and structural maturation of auditory cortex from 2 months to 2 years old

In school-age children, the myelination of the auditory radiation thalamocortical pathway is associated with the latency of auditory evoked responses, with the myelination of thalamocortical axons facilitating the rapid propagation of acoustic information. Little is known regarding this auditory system function-structure association in infants and toddlers. The present study tested the hypothesis that maturation of auditory radiation white-matter microstructure (e.g., fractional anisotropy (FA); measured using diffusion-weighted MRI) is associated with the latency of the infant auditory response (P2m measured using magnetoencephalography, MEG) in a cross-sectional (2 to 24 months) as well as longitudinal cohort (2 to 29 months) of typically developing infants and toddlers. In the cross-sectional sample, non-linear maturation of P2m latency and auditory radiation diffusion measures were observed. After removing the variance associated with age in both P2m latency and auditory radiation diffusion measures, auditory radiation still accounted for significant variance in P2m latency. In the longitudinal sample, latency and FA associations could be observed at the level of a single child. Findings provide strong support for a contribution of auditory radiation white matter to rapid cortical auditory encoding processes in infants.

neuroscience↗