Studying Brain Function in Children Using Magnetoencephalography

Abstract

Magnetoencephalography (MEG) is a non-invasive neuroimaging technique which directly measures magnetic fields produced by the electrical activity of the human brain. MEG is quiet and less likely to induce claustrophobia compared with magnetic resonance imaging (MRI). It is therefore a promising tool for investigating brain function in young children. However, analysis of MEG data from pediatric populations is often complicated by head movement artefacts which arise as a consequence of the requirement for a spatially-fixed sensor array that is not affixed to the child's head. Minimizing head movements during MEG sessions can be particularly challenging as young children are often unable to remain still during experimental tasks. The protocol presented here aims to reduce head movement artefacts during pediatric MEG scanning. Prior to visiting the MEG laboratory, families are provided with resources that explain the MEG system and the experimental procedures in simple, accessible language. An MEG familiarization session is conducted during which children are acquainted with both the researchers and the MEG procedures. They are then trained to keep their head still whilst lying inside an MEG simulator. To help children feel at ease in the novel MEG environment, all of the procedures are explained through the narrative of a space mission. To minimize head movement due to restlessness, children are trained and assessed using fun and engaging experimental paradigms. In addition, children's residual head movement artefacts are compensated for during the data acquisition session using a real-time head movement tracking system. Implementing these child-friendly procedures is important for improving data quality, minimizing participant attrition rates in longitudinal studies, and ensuring that families have a positive research experience.

The preterm social brain: altered functional networks for Theory of Mind in very preterm children

“…A consequence of this is that the sample of VPT children that contributed to the neuroimaging findings may not be representative of the initial VPT group recruited at birth on cognitive abilities, although the neonatal variables did not differ between those retained and those lost to follow-up. Another limitation which is common to other paediatric neuroimaging studies is loss of data due to head motion ( Pang, 2011 ; Rapaport et al ., 2019 ); head motion contributed to loss of data from six VPT and five FT subjects in the fMRI and two VPT and three FT subjects in the MEG.…”

Interference suppression techniques for OPM-based MEG: Opportunities and challenges

“…Recent neuroscientific work has used OPMs to detect a range of neuromagnetic fields whilst participants made natural head movements, for example, beta-band modulations during a “ping-pong” paradigm ( Boto et al., 2018 ; Holmes et al., 2018 ), and auditory evoked fields during continuous head movement while standing ( Seymour et al., 2021 ). This opens up a range of exciting experimental and clinical opportunities for OPM-based MEG experiments, including paediatric studies ( Feys et al., 2021 ; Rapaport et al., 2019 ), and the incorporation of naturalistic movements into neuroimaging paradigms ( Roberts et al., 2019 ; Sonkusare et al., 2019 ). The wearability of OPMs also means that participants are not required to keep still for long periods of time, aiding participant comfort and potentially improving the quality of experimental data.…”

Reduced auditory steady state responses in autism spectrum disorder

“…Given that the 40 Hz ASSRs continue to mature throughout late adolescence and adulthood [50], it remains to be established, whether the development of ASSRs in ASD is simply delayed, or whether reductions persist throughout life. To investigate this further, future studies should use high-powered longitudinal ASD samples and age-appropriate MEG systems [76], to characterise ASSR development throughout childhood, adolescence and into adulthood [77]. If confirmed, divergent ASSR trajectories could act as important autism-relevant markers of intervention efficacy [78].…”