A5054771038- Functional Brain Connectivity Studies
- Atomic and Subatomic Physics Research
- Advanced MRI Techniques and Applications
- EEG and Brain-Computer Interfaces
- Epilepsy research and treatment
- Neural dynamics and brain function
- Non-Invasive Vital Sign Monitoring
- Magnetic and transport properties of perovskites and related materials
- Vestibular and auditory disorders
- Neuroscience and Neuropharmacology Research
- Hand Gesture Recognition Systems
- Genetics and Neurodevelopmental Disorders
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum optics and atomic interactions
- Muscle activation and electromyography studies
- Motor Control and Adaptation
- Radiomics and Machine Learning in Medical Imaging
- Heart Rate Variability and Autonomic Control
- Neonatal and fetal brain pathology
- Open Education and E-Learning
- Electron Spin Resonance Studies
- Pharmacological Effects and Toxicity Studies
- Brain Tumor Detection and Classification
- Context-Aware Activity Recognition Systems
- Advanced NMR Techniques and Applications
University College London
2016-2025
National Hospital for Neurology and Neurosurgery
2018-2025
Wellcome Centre for Human Neuroimaging
2018-2024
MRC Human Immunology Unit
2022
Great Ormond Street Hospital
2017
Brigham and Women's Hospital
2015
Harvard University
2015
The Francis Crick Institute
2002
Small, commercially-available Optically Pumped Magnetometers (OPMs) can be used to construct a wearable Magnetoencephalography (MEG) system that allows large head movements made during recording. The small dynamic range of these sensors however means movement in the residual static magnetic field found inside typical Magnetically Shielded Rooms (MSRs) saturate sensor outputs, rendering data unusable. This problem ameliorated by using set electromagnetic coils attenuate spatially-varying...
Statistical Parametric Mapping (SPM) is an integrated set of methods for testing hypotheses about the brain's structure and function, using data from imaging devices. These are implemented in open source software package, SPM, which has been continuous development more than 30 years by international community developers. This paper reports release SPM 25.01, a major new version that incorporates novel analysis methods, optimisations existing as well improved practices science development.
Abstract The human brain undergoes significant functional and structural changes in the first decades of life, as foundations for cognition are laid down. However, non-invasive imaging techniques to investigate function throughout neurodevelopment limited due growth head-size with age substantial head movement young participants. Experimental designs probe also by unnatural environment typical systems impose. developments quantum technology allowed fabrication a new generation wearable...
To allow wearable magnetoencephalography (MEG) recordings to be made on unconstrained subjects the spatially inhomogeneous remnant magnetic field inside magnetically shielded room (MSR) must nulled. Previously, a large bi-planar coil system which produces uniform fields and gradients was used for this purpose. Its construction presented significant challenge, six distinct coils were wound two 1.6 × m2 planes. Here, we exploit shared symmetries produce simultaneously optimised generate...
Traditional magnetoencephalographic (MEG) brain imaging scanners consist of a rigid sensor array surrounding the head; this means that they are maximally sensitive to superficial structures. New technology based on optical pumping we can now consider more flexible and creative placement. Here explored magnetic fields generated by model human hippocampus not only across scalp but also at roof mouth. We found simulated hippocampal sources gave rise dipolar field patterns with one surface...
Here we propose that much of the magnetic interference observed when using optically pumped magnetometers for MEG experiments can be modeled as a spatially homogeneous field. We show this approximation reduces sensor level variance and substantially improves statistical power. This model does not require knowledge underlying neuroanatomy nor positions. It only needs information about orientation. Due to model's low rank there is little risk removing substantial neural signal. However,...
Optically pumped magnetometer-based magnetoencephalography (OP-MEG) can be used to measure neuromagnetic fields while participants move in a magnetically shielded room. Head movements previous OP-MEG studies have been up 20 cm translation and ∼30° rotation sitting position. While this represents step-change over stationary MEG systems, naturalistic head movement is likely exceed these limits, particularly when are standing up. In proof-of-concept study, we sought push the limits of even...
Magnetically shielded rooms (MSRs) use multiple layers of materials such as MuMetal to screen external magnetic fields that would otherwise interfere with high precision field measurements magnetoencephalography (MEG). Optically pumped magnetometers (OPMs) have enabled the development wearable MEG systems which potential provide a motion tolerant functional brain imaging system spatiotemporal resolution. Despite significant promise, OPMs impose stringent shielding requirements, operating...
One of the primary technical challenges facing magnetoencephalography (MEG) is that magnitude neuromagnetic fields several orders lower than interfering signals. Recently, a new type sensor has been developed - optically pumped magnetometer (OPM). These sensors can be placed directly on scalp and move with head during participant movement, making them wearable. This opens up range exciting experimental clinical opportunities for OPM-based MEG experiments, including paediatric studies,...
The ability to collect high-quality neuroimaging data during ambulatory participant movement would enable a wealth of neuroscientific paradigms. Wearable magnetoencephalography (MEG) based on optically pumped magnetometers (OPMs) has the potential allow scan. However, strict zero magnetic field requirement OPMs means that systems must be operated inside magnetically shielded room (MSR) and also require active shielding using electromagnetic coils cancel residual fields changes (due external...
Abstract Magneto- and electroencephalography (MEG/EEG) are important techniques for the diagnosis pre-surgical evaluation of epilepsy. Yet, in current cryogen-based MEG systems sensors offset from scalp, which limits signal-to-noise ratio (SNR) thereby sensitivity to activity deep structures such as hippocampus. This effect is amplified children, whom adult-sized fixed-helmet typically too big. Moreover, ictal recordings with problematic because limited movement tolerance and/or logistical...
The spinal cord and its interactions with the brain are fundamental for movement control somatosensation. However, electrophysiology in humans have largely been treated as distinct enterprises, part due to relative inaccessibility of cord. Consequently, there is a dearth knowledge on human electrophysiology, including multiple pathologies that affect well brain.
Optically-pumped (OP) magnetometers allow magnetoencephalography (MEG) to be performed while a participant's head is unconstrained. To fully leverage this new technology, and in particular its capacity for mobility, the activity of deep brain structures which facilitate explorative behaviours such as navigation, must detectable using OP-MEG. One crucial region hippocampus. Here we had three healthy adult participants perform hippocampal-dependent task – imagination novel scene imagery being...
Recent work has demonstrated that Optically Pumped Magnetometers (OPMs) can be utilised to create a wearable Magnetoencephalography (MEG) system is motion robust. In this study, we use map eloquent cortex using clinically validated language lateralisation paradigm (covert verb generation: 120 trials, ∼10 min total duration) in healthy adults (n = 3). We show it possible lateralise and localise function on case by basis system. Specifically, at sensor source level reliably detect lateralising...
Abstract We demonstrate the first use of Optically Pumped Magnetoencephalography (OP‐MEG) in an epilepsy patient with unrestricted head movement. Current clinical MEG uses a traditional SQUID system, where sensors are cryogenically cooled and housed helmet which patient’s is fixed. Here, we different type sensor (OPM), operates at room temperature can be placed directly on scalp, permitting free performed OP‐MEG recording refractory focal epilepsy. OP‐MEG‐identified analogous interictal...
In this study we explore the interference rejection and spatial sampling properties of multi-axis Optically Pumped Magnetometer (OPM) data. We use both vector spherical harmonics eigenspectra to quantify how well an array can separate neuronal signal from environmental while adequately entire cortex. found that triaxial OPMs have superb noise allowing for very high orders (L=6) be accounted minimally affecting neural space (2dB attenuation a 60-sensor system). show at least 11th order (143...
Most neuroimaging techniques require the participant to remain still for reliable recordings be made. Optically pumped magnetometer (OPM) based magnetoencephalography (OP-MEG) however, is a technique which can used measure neural signals during large movement (approximately 1 m) within magnetically shielded room (MSR) (Boto et al., 2018; Seymour 2021). Nevertheless, environmental magnetic fields vary both spatially and temporally OPMs only operate limited field range, constrains movement....
Abstract Multipole expansions have been used extensively in the Magnetoencephalography (MEG) literature for mitigating environmental interference and modelling brain signal. However, their application to Optically Pumped Magnetometer (OPM) data is challenging due wide variety of existing OPM sensor array designs. We therefore explore how such multipole models can be adapted provide stable signal across systems. Firstly, we demonstrate prolate spheroidal (rather than spherical) harmonics a...
Although it has been consistently found that local blood-oxygen-level-dependent (BOLD) changes are better modelled by a combination of the power multiple EEG frequency bands rather than unique band alone, electro-haemodynamic coupling function is not yet fully characterised. Electrophysiological studies have revealed strength between phase low- and amplitude high- activities (phase-amplitude - PAC) an important role in brain general, preparation execution movement particular. Using...
Key points The application of conventional cryogenic magnetoencephalography (MEG) to the study cerebellar functions is highly limited because typical sensor arrays are far away from cerebellum and naturalistic movement not allowed in recording. A new generation MEG using optically pumped magnetometers (OPMs) that can be worn on head during has opened up an opportunity image electrophysiological activity non‐invasively. We use OPMs record human signals elicited by air‐puff stimulation eye....
Optically pumped magnetometers (OPMs) have made moving, wearable magnetoencephalography (MEG) possible. The OPMs typically used for MEG require a low background magnetic field to operate, which is achieved using both passive and active shielding. However, the never truly zero Tesla, so at each of changes as participant moves. This leads position orientation dependent in measurements, manifest frequency artefacts data.