A5075585675- Advanced MRI Techniques and Applications
- Autism Spectrum Disorder Research
- Functional Brain Connectivity Studies
- Neuroscience and Neuropharmacology Research
- Neural dynamics and brain function
- Attention Deficit Hyperactivity Disorder
- Advanced NMR Techniques and Applications
- Genetics and Neurodevelopmental Disorders
- Neuroscience and Neural Engineering
- Tactile and Sensory Interactions
- EEG and Brain-Computer Interfaces
- Obsessive-Compulsive Spectrum Disorders
- Electron Spin Resonance Studies
- Neural and Behavioral Psychology Studies
- Transcranial Magnetic Stimulation Studies
- Advanced Neuroimaging Techniques and Applications
- GABA and Rice Research
- Biochemical effects in animals
- Behavioral and Psychological Studies
- Photoreceptor and optogenetics research
- Memory and Neural Mechanisms
- Child Nutrition and Feeding Issues
- Motor Control and Adaptation
- Neuroscience and Music Perception
- Medical Imaging Techniques and Applications
King's College London
2020-2025
South London and Maudsley NHS Foundation Trust
2025
Kennedy Krieger Institute
2012-2021
Johns Hopkins University
2012-2021
NeuroDevelopment Center
2020-2021
Johns Hopkins Medicine
2012-2020
Cardiff University
2011-2019
Resonance Research (United States)
2018
Mayo Clinic
2018
The purpose of this study is to describe the Gannet toolkit for quantitative batch analysis gamma-aminobutyric acid (GABA) -edited MRS data.Using MEGA-PRESS editing and standard acquisition parameters, four spectra were acquired in three brain regions 10 healthy volunteers. These 120 datasets processed without user intervention with Gannet, a Matlab-based tool that takes raw time-domain data input, processes it generate frequency-domain edited spectrum, applies simple modeling procedure...
Purpose To develop a tissue correction for GABA‐edited magnetic resonance spectroscopy (MRS) that appropriately addresses differences in voxel gray matter (GM), white (WM), and cerebrospinal fluid (CSF) fractions. Materials Methods Simulations compared the performance of approaches. Corrections were then applied to vivo data from 16 healthy volunteers, acquired at 3T. GM, WM, CSF fractions determined T 1 ‐weighted images. content, GM/WM GABA water relaxation three compartments are combined...
Impaired responses to tactile stimulation are a commonly reported symptom among children with autism spectrum disorder (ASD). Furthermore, impairments in filtering or habituation input have been described ASD. This study measured different aspects of processing investigate atypical touch sensitivity ASD, methodology that has not previously used this population. Sixty-seven typically developing (TDC) and 32 ASD (ages 8–12) completed vibrotactile tasks assessing: reaction time (RT); static...
Abnormal responses to tactile stimuli are a common feature of autism spectrum disorder (ASD). Several lines evidence suggest that GABAergic function, which has crucial role in processing, is altered ASD. In this study, we determine whether vivo GABA levels children with ASD, and alterations associated abnormal function these children.GABA-edited magnetic resonance spectroscopy was acquired 37 Autism 35 typically developing (TDC) from voxels over primary sensorimotor occipital cortices....
The excitatory/inhibitory (E/I) imbalance hypothesis posits that between excitatory (glutamatergic) and inhibitory (GABAergic) mechanisms underlies the behavioral characteristics of autism. However, how E/I arises it may differ across autism symptomatology brain regions is not well understood. We used innovative analysis methods-combining competitive gene-set gene-expression profiles in relation to cortical thickness (CT) investigate relationships genetic variance, structure participants...
The neural mechanisms underlying variability in human sensory perception remain incompletely understood. In particular, few studies have attempted to investigate the relationship between vivo measurements of neurochemistry and individuals' behavioral performance. Our previous work found a GABA concentration visual cortex orientation discrimination thresholds (Edden et al., 2009). present study, we used magnetic resonance spectroscopy psychophysical testing vibrotactile frequency whether...
Tourette Syndrome (TS) is characterized by the presence of chronic tics. Individuals with TS often report difficulty ignoring (habituating to) tactile sensations, and some patients perceive that this contributes to a “premonitory urge” tic. While common, physiological basis impaired processing in TS, indeed tics themselves, remain poorly understood. It has been well established GABAergic plays an important role shaping neurophysiological response stimulation. Furthermore, there are multiple...
Edited magnetic resonance spectroscopy makes possible noninvasive studies of the role inhibitory neurotransmitter GABA in healthy brain and disease processes. A major limitation methodology is coediting macromolecular signals. Although it has previously been shown that signal can be suppressed using a symmetrical editing scheme, this approach rarely applied at field strength 3T as insufficiently selective pulses result loss (in addition to intended suppression signal). In article, authors...
Healthy aging is accompanied by motor inhibition deficits that involve a slower process of stopping prepotent response (i.e., reactive inhibition) rather than diminished ability to anticipate proactive inhibition). Some studies suggest efficient related GABAergic function. Since age-related alterations in the GABA system have also been reported, impairments might be linked cortico-subcortical network mediates inhibition. Thirty young human adults (mean age, 23.2 years; age range, 18–34 14...
Purpose To investigate the quantitative impact of frequency drift on Gamma-Aminobutyric acid (GABA+)-edited MRS human brain at 3 Tesla (T). Methods Three sequential GABA+-edited MEGA-PRESS acquisitions were acquired in fifteen sessions; ten these, was preceded by functional MRI (fMRI) to induce drift, which estimated from creatine resonance 3.0 ppm. Simulations performed examine effects editing efficiency GABA and co-edited macromolecules (MM) subtraction artifacts GABA+ quantification. The...
Purpose The conventional spectral-editing experiment used to measure GABA in the human brain also contains a contribution from macromolecules (MM), and combined plus MM signal is often referred as "GABA+". More recently, methods have been developed estimate free contamination. In this study, relationship between acquired with suppression GABA+ measurements was examined. Methods GABA-edited MEGA-PRESS experiments without were performed sensorimotor occipital cortex of 12 healthy subjects at 3...
Purpose To investigate the effects of B0 field offsets and drift on macromolecule (MM)-suppressed GABA-editing experiments, to implement test a prospective correction scheme. "Symmetric" editing schemes are proposed suppress unwanted coedited MM signals in GABA editing. Materials Methods Full density-matrix simulations both conventional (nonsymmetric) symmetric MM-suppressed were performed for spin system evaluate their offset-dependence. Phantom vivo (15 subjects at 3T) GABA-edited...