Reproducible paired sources from concurrent EEG-fMRI data using BICAR.
We introduce BICAR, an algorithm for obtaining robust, reproducible pairs of temporal and spatial components at the individual subject level from concurrent electroencephalographic and functional magnetic resonance imaging data. BICAR assigns a task-independent measure of component quality, reproducibility, to each paired source. Under BICAR a reproducibility cutoff is derived that can be used to objectively discard spuriously paired EEG-fMRI components. BICAR is run on minimally processed data: fMRI images undergo the standard preprocessing steps (alignment, motion correction, etc.) and EEG data, after scanner artifact removal, are simply bandpass filtered. This minimal processing allows the secondary scoring of the same set of BICAR components for a variety of different endpoint analyses; in this manuscript we propose a general method for scoring components for task event synchronization (evoked response analysis), but scoring using many other criteria, for example frequency content, are possible. BICAR is applied to five subjects performing a visual search task, and among the most reproducible components we find biologically relevant paired sources involved in visual processing, motor planning, execution, and attention.
Department of Physics, University of California, Santa Barbara, CA 93106, USA; Institute for Collaborative Biotechnologies, University of California, Santa Barbara, CA 93106, USA; Chemical and Biomolecular Engineering, University of Connecticut, Storrs, CT 06269, USA; Department of Marine Sciences, University of Connecticut, Groton, CT 06340, USA. Electronic address: kevin.s.brown@uconn.edu.
Kevin S
KS
Brown
Ryan
R
Kasper
Barry
B
Giesbrecht
Jean M
JM
Carlson
Scott T
ST
Grafton
D000328:Adult; D000465:Algorithms; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D015203:Reproducibility of Results; D055815:Young Adult
Concurrent EEG-fMRI; EEG; Independent component analysis; Multimodal data fusion; fMRI