Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2006-5-23
pubmed:abstractText
Cerebral currents responsible for the extra-cranially recorded magnetoencephalography (MEG) data can be estimated by applying a suitable source model. A popular choice is the distributed minimum-norm estimate (MNE) which minimizes the l2-norm of the estimated current. Under the l2-norm constraint, the current estimate is related to the measurements by a linear inverse operator. However, the MNE has a bias towards superficial sources, which can be reduced by applying depth weighting. We studied the effect of depth weighting in MNE using a shift metric. We assessed the localization performance of the depth-weighted MNE as well as depth-weighted noise-normalized MNE solutions under different cortical orientation constraints, source space densities, and signal-to-noise ratios (SNRs) in multiple subjects. We found that MNE with depth weighting parameter between 0.6 and 0.8 showed improved localization accuracy, reducing the mean displacement error from 12 mm to 7 mm. The noise-normalized MNE was insensitive to depth weighting. A similar investigation of EEG data indicated that depth weighting parameter between 2.0 and 5.0 resulted in an improved localization accuracy. The application of depth weighting to auditory and somatosensory experimental data illustrated the beneficial effect of depth weighting on the accuracy of spatiotemporal mapping of neuronal sources.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1053-8119
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
160-71
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:16520063-Adult, pubmed-meshheading:16520063-Artifacts, pubmed-meshheading:16520063-Auditory Cortex, pubmed-meshheading:16520063-Brain Mapping, pubmed-meshheading:16520063-Cerebral Cortex, pubmed-meshheading:16520063-Electroencephalography, pubmed-meshheading:16520063-Female, pubmed-meshheading:16520063-Humans, pubmed-meshheading:16520063-Image Processing, Computer-Assisted, pubmed-meshheading:16520063-Imaging, Three-Dimensional, pubmed-meshheading:16520063-Linear Models, pubmed-meshheading:16520063-Magnetic Resonance Imaging, pubmed-meshheading:16520063-Magnetoencephalography, pubmed-meshheading:16520063-Male, pubmed-meshheading:16520063-Neurons, pubmed-meshheading:16520063-Reference Values, pubmed-meshheading:16520063-Sensitivity and Specificity, pubmed-meshheading:16520063-Signal Processing, Computer-Assisted, pubmed-meshheading:16520063-Software, pubmed-meshheading:16520063-Somatosensory Cortex, pubmed-meshheading:16520063-Temporal Lobe
pubmed:year
2006
pubmed:articleTitle
Assessing and improving the spatial accuracy in MEG source localization by depth-weighted minimum-norm estimates.
pubmed:affiliation
MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Building 149 13th St. Charlestown, MA 02129, USA. fhlin@nmr.mgh.harvard.edu
pubmed:publicationType
Journal Article, Comparative Study, Research Support, N.I.H., Extramural