LOCALIZATION OF INDEPENDENT COMPONENTS FROM MAGNETOENCEPHALOGRAPHY
Akaysha C. Tang, 123 Dan Phung, 12 Barak A. Pearlmutter, 23 Robert Christner 4
Blind source separation (BSS) decomposes a multidi-
mensional time series into a set of sources, each with
a one-dimensional time course and a xed spatial dis-
tribution. For EEG and MEG, the former corresponds
to the simultaneously separated and temporally over-
lapping signals for continuous non-averaged data; the
latter corresponds to the set of attenuations from the
sources to the sensors. These sensor projection vec-
tors give information on the spatial locations of the
sources. Here we use standard Neuromag dipole- tting
software to localize BSS-separated components of MEG
data collected in several tasks in which visual, audi-
tory, and somatosensory stimuli all play a role. We
found that BSS-separated components with stimulus-
or motor-locked responses can be localized to physio-
logical and anatomically meaningful locations within
the brain.