title: Five-dimensional neuroimaging: localization of the time-frequency dynamics of cortical activity.
abstract: The spatiotemporal dynamics of cortical oscillations across human brain regions remain poorly understood because of a lack of adequately validated methods for reconstructing such activity from noninvasive electrophysiological data. In this paper, we present a novel adaptive spatial filtering algorithm optimized for robust source time-frequency reconstruction from magnetoencephalography (MEG) and electroencephalography (EEG) data. The efficacy of the method is demonstrated with simulated sources and is also applied to real MEG data from a self-paced finger movement task. The algorithm reliably reveals modulations both in the beta band (12-30 Hz) and high gamma band (65-90 Hz) in sensorimotor cortex. The performance is validated by both across-subjects statistical comparisons and by intracranial electrocorticography (ECoG) data from two epilepsy patients. Interestingly, we also reliably observed high frequency activity (30-300 Hz) in the cerebellum, although with variable locations and frequencies across subjects. The proposed algorithm is highly parallelizable and runs efficiently on modern high-performance computing clusters. This method enables the ultimate promise of MEG and EEG for five-dimensional imaging of space, time, and frequency activity in the brain and renders it applicable for widespread studies of human cortical dynamics during cognition.
authors: Department of Radiology, University of California, San Francisco, CA 94143-0628, USA.
authors: Sarang S
authors: SS
authors: Dalal
authors: Adrian G
authors: AG
authors: Guggisberg
authors: Erik
authors: E
authors: Edwards
authors: Kensuke
authors: K
authors: Sekihara
authors: Anne M
authors: AM
authors: Findlay
authors: Ryan T
authors: RT
authors: Canolty
authors: Mitchel S
authors: MS
authors: Berger
authors: Robert T
authors: RT
authors: Knight
authors: Nicholas M
authors: NM
authors: Barbaro
authors: Heidi E
authors: HE
authors: Kirsch
authors: Srikantan S
authors: SS
authors: Nagarajan
mesh_terms: D000328:Adult; D000465:Algorithms; D001611:Beta Rhythm; D002531:Cerebellum / Q000033:anatomy & histology / Q000502:physiology; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000502:physiology*; D003627:Data Interpretation, Statistical; D004569:Electroencephalography; D004594:Electrophysiology; D005260:Female; D005385:Fingers / Q000294:innervation / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D015225:Magnetoencephalography; D008297:Male; D009044:Motor Cortex / Q000033:anatomy & histology / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D013003:Somatosensory Cortex / Q000033:anatomy & histology / Q000502:physiology