Abstract:
:We describe a system that localizes a single dipole to reasonable accuracy from noisy magnetoencephalographic (MEG) measurements in real time. At its core is a multilayer perceptron (MLP) trained to map sensor signals and head position to dipole location. Including head position overcomes the previous need to retrain the MLP for each subject and session. The training dataset was generated by mapping randomly chosen dipoles and head positions through an analytic model and adding noise from real MEG recordings. After training, a localization took 0.7 ms with an average error of 0.90 cm. A few iterations of a Levenberg-Marquardt routine using the MLP output as its initial guess took 15 ms and improved accuracy to 0.53 cm, which approaches the natural limit on accuracy imposed by noise. We applied these methods to localize single dipole sources from MEG components isolated by blind source separation and compared the estimated locations to those generated by standard manually assisted commercial software.
journal_name
Hum Brain Mappjournal_title
Human brain mappingauthors
Jun SC,Pearlmutter BAdoi
10.1002/hbm.20068keywords:
subject
Has Abstractpub_date
2005-01-01 00:00:00pages
21-34issue
1eissn
1065-9471issn
1097-0193journal_volume
24pub_type
杂志文章abstract::The luminance contrast of a visual stimulus is known to modulate the response properties of areas V1 and the human MT complex (hMT+), but has not been shown to modulate interactions between these two areas. We examined the direction of information transfer between V1/V2 and hMT+ at different stimulus contrasts by meas...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.20495
更新日期:2009-01-01 00:00:00
abstract::The overall goal of this work is to demonstrate how resting state functional magnetic resonance imaging (fMRI) signals may be used to objectively parcellate functionally heterogeneous subregions of the human amygdala into structures characterized by similar patterns of functional connectivity. We hypothesize that simi...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.22249
更新日期:2014-04-01 00:00:00
abstract::Humans take a long time to respond to the slow visual motion of an object. It is not known what neural mechanism causes this delay. We measured magnetoencephalographic neural responses to light spot motion onset within a wide speed range (0.4-500 degrees /sec) and compared these with human reaction times (RTs). The me...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.10033
更新日期:2002-06-01 00:00:00
abstract::Working memory (WM) for auditory information has been thought of as a unitary system, but whether WM for verbal and tonal information relies on the same or different functional neuroarchitectures has remained unknown. This fMRI study examines verbal and tonal WM in both nonmusicians (who are trained in speech, but not...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.21060
更新日期:2011-05-01 00:00:00
abstract::Variability quenching is a widespread neural phenomenon in which trial-to-trial variability (TTV) of neural activity is reduced by repeated presentations of a sensory stimulus. However, its neural mechanism and functional significance remain poorly understood. Recurrent network dynamics are suggested as a candidate me...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.24304
更新日期:2018-11-01 00:00:00
abstract::Rasagiline is a monoamine oxidase type B inhibitor that possesses no amphetamine-like properties, and provides symptomatic relief in early and late stages of Parkinson's disease (PD). Data in animal models of PD suggest that chronic administration of rasagiline is associated with structural changes in the substantia n...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.23213
更新日期:2016-08-01 00:00:00
abstract::Hypercoupling of activity in speech-perception-specific brain networks has been proposed to play a role in the generation of auditory-verbal hallucinations (AVHs) in schizophrenia; however, it is unclear whether this hypercoupling extends to nonverbal auditory perception. We investigated this by comparing schizophreni...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.23934
更新日期:2018-04-01 00:00:00
abstract::We investigated the role of the dopamine system [i.e., subcortical-medial prefrontal cortex (mPFC) network] in dreaming, by studying patients with Parkinson's Disease (PD) as a model of altered dopaminergic transmission. Subcortical volumes and cortical thickness were extracted by 3T-MR images of 27 PD patients and 27...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.23095
更新日期:2016-03-01 00:00:00
abstract::To capture patterns of normal age-associated atrophy, we previously used a multivariate statistical approach applied to voxel based morphometry that identified age-associated gray and white matter covariance networks (Brickman et al. [2007]: Neurobiol Aging 28:284-295). The current study sought to examine the stabilit...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.20452
更新日期:2008-10-01 00:00:00
abstract::Baseline activity of resting state brain networks (RSN) in a resting subject has become one of the fastest growing research topics in neuroimaging. It has been shown that up to 12 RSNs can be differentiated using an independent component analysis (ICA) of the blood oxygen level dependent (BOLD) resting state data. In ...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.20813
更新日期:2009-12-01 00:00:00
abstract::The neural systems sustaining object naming were examined using the activation likelihood estimation (ALE) meta-analysis approach on the results of 16 previously published studies. The activation task in each study required subjects to name pictures of objects or animals, but the baseline tasks varied. Separate meta-a...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.20132
更新日期:2005-05-01 00:00:00
abstract::We used computer simulations to investigate finite element models of the layered structure of the human skull in EEG source analysis. Local models, where each skull location was modeled differently, and global models, where the skull was assumed to be homogeneous, were compared to a reference model, in which spongy an...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.21114
更新日期:2011-09-01 00:00:00
abstract::Humans can easily recognize others' facial expressions. Among the brain substrates that enable this ability, considerable attention has been paid to face-selective areas; in contrast, whether motion-sensitive areas, which clearly exhibit sensitivity to facial movements, are involved in facial expression recognition re...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.23578
更新日期:2017-06-01 00:00:00
abstract::Although the brain areas in the default-mode network (DMN) act in a coordinated way during rest, the activity levels in the individual areas of the DMN are highly heterogeneous. The relation between the activity levels and the pattern of causal interaction among the DMN areas remains unknown. In the present fMRI study...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.21065
更新日期:2011-01-01 00:00:00
abstract::Sedation has a graded effect on brain responses to auditory stimuli: perceptual processing persists at sedation levels that attenuate more complex processing. We used fMRI in healthy volunteers sedated with propofol to assess changes in neural responses to spoken stimuli. Volunteers were scanned awake, sedated, and du...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.22375
更新日期:2014-07-01 00:00:00
abstract::We demonstrate that multivoxel pattern analysis can be used to decode place-related information in fMRI. Subjects performed a working memory version of the Morris water maze task in a virtual environment with a single wall cue. The voxel data that corresponds to when subjects were located at the goal was extracted for...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.20873
更新日期:2010-03-01 00:00:00
abstract::The BrainMap database is a community resource that curates peer-reviewed, coordinate-based human neuroimaging literature. By pairing the results of neuroimaging studies with their relevant meta-data, BrainMap facilitates coordinate-based meta-analysis (CBMA) of the neuroimaging literature en masse or at the level of e...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.24078
更新日期:2018-08-01 00:00:00
abstract::What is the neural substrate of our capability to properly react to changes in the environment? It can be hypothesized that the anterior cingulate cortex (ACC) manages repetitive stimuli in routine conditions and alerts the dorsolateral prefrontal cortex (PFC) when stimulation unexpectedly changes. To provide evidence...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.20491
更新日期:2009-01-01 00:00:00
abstract::Mathematical word problems are ubiquitous and standard for teaching and evaluating generalization of mathematical knowledge for real-world contexts. It is therefore concerning that the neural mechanisms of word problem solving are not well understood, as these insights represent strong potential for improving educatio...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.24502
更新日期:2019-04-15 00:00:00
abstract::Past research has found that neural activity associated with feedback processing is enhanced by positive approach-motivated states. However, no past work has examined how reward processing changes in the context of revenge. Using a novel aggression paradigm, we sought to explore the influence of approach-motivated ang...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.25177
更新日期:2020-12-01 00:00:00
abstract::Current neuroscientific research has shown that the brain reconfigures its functional interactions at multiple timescales. Here, we sought to link transient changes in functional brain networks to individual differences in behavioral and cognitive performance by using an active learning paradigm. Participants learned ...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.23285
更新日期:2016-11-01 00:00:00
abstract::Spatial leakage effects are particularly confounding for seed-based investigations of brain networks using source-level electroencephalography (EEG) or magnetoencephalography (MEG). Various methods designed to avoid this issue have been introduced but are limited to particular assumptions about its temporal characteri...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.22943
更新日期:2015-11-01 00:00:00
abstract::Previous studies have led to the proposal that patients with Alzheimer's disease (AD) may have disturbed functional connectivity between different brain regions. Furthermore, recent resting-state functional magnetic resonance imaging (fMRI) studies have also shown that low-frequency (<0.08 Hz) fluctuations (LFF) of th...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.20324
更新日期:2007-10-01 00:00:00
abstract::A persistent problem in developing plausible neurophysiological models of perception, cognition, and action is the difficulty of characterizing the interactions between different neural systems. Previous studies have approached this problem by estimating causal influences across brain areas activated during cognitive ...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.20772
更新日期:2009-06-01 00:00:00
abstract:OBJECTIVE:To determine the functional connectivity of different EEG bands at the "baseline" situation (rest) and during mathematical thinking in children and young adults to study the maturation effect on brain networks at rest and during a cognitive task. METHODS:Twenty children (8-12 years) and twenty students (21-2...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.20492
更新日期:2009-01-01 00:00:00
abstract::Rapid emotion processing is an ecologically essential ability for survival in social environments in which threatening or advantageous encounters dynamically and rapidly occur. Efficient emotion recognition is subserved by different processes, depending on one's expectations; however, the underlying functional and str...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.24779
更新日期:2019-12-15 00:00:00
abstract::This study investigated the cortical responses underlying magnitude comparisons of multisensory stimuli and examined the effect that musical expertise has in this process. The comparative judgments were based on a newly learned rule binding the auditory and visual stimuli within the context of magnitude comparisons: "...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.22558
更新日期:2014-11-01 00:00:00
abstract::MR-based measurements of brain volumes may be affected by the presence of white matter (WM) lesions. Here, we assessed how and to what extent this may happen for WM lesions of various sizes and intensities. After inserting WM lesions of different sizes and intensities into T1-W brain images of healthy subjects, we ass...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.21344
更新日期:2012-09-01 00:00:00
abstract::To generate imaging biomarkers from disease-specific brain networks, we have implemented a general toolbox to rapidly perform scaled subprofile modeling (SSM) based on principal component analysis (PCA) on brain images of patients and normals. This SSMPCA toolbox can define spatial covariance patterns whose expression...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.22295
更新日期:2014-05-01 00:00:00
abstract::Functional connectivity analysis of brain networks has become an important tool for investigation of human brain function. Although functional connectivity computations are usually based on resting-state data, the application to task-specific fMRI has received growing attention. Three major methods for extraction of r...
journal_title:Human brain mapping
pub_type: 杂志文章
doi:10.1002/hbm.22897
更新日期:2015-10-01 00:00:00