MEG-based imaging of focal neuronal current sources
- University of Southern California, Los Angeles, CA (United States)
- Los Alamos National Lab., NM (United States)
We describe a new approach to imaging neuronal current sources from measurements of the magnetoencephalogram (MEG) associated with sensory, motor, or cognitive brain activation. Previous approaches to this problem have concentrated on the use of weighted minimum norm inverse methods. While these methods ensure a unique solution, they do not introduce information specific to the MEG inverse problem, often producing overly smoothed solutions and exhibiting severe sensitivity to noise. We describe a Bayesian formulation of the inverse problem in which a Gibbs prior is constructed to reflect the sparse focal nature of neuronal current sources associated with evoked response data. The prior involves a binary process indicating active sources and a continuous Gaussian process designating associated amplitudes. An estimate of the primary current source distribution for a specific data set is formed by maximizing over the posterior probability with respect to the binary and continuous variables.
- Research Organization:
- Los Alamos National Lab., NM (United States)
- Sponsoring Organization:
- National Insts. of Health, Bethesda, MD (United States); National Eye Inst., Bethesda, MD (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 400182
- Report Number(s):
- LA-UR--96-1942; CONF-9602101--8; ON: DE96012734; CNN: NIH Grant R01-MH53213; NEI Grant R01-EY08610-04
- Country of Publication:
- United States
- Language:
- English
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