Qualcomm Institute, University of California San Diego

MEG source imaging method using fast L1 minimum-norm and its applications to signals with brain noise and human resting-state source amplitude images

  • NeuroImage
  • September 2013

The present study developed a fastMEG source imaging technique based on Fast Vector-based Spatio-Temporal Analysis using a L1-minimum-norm (Fast-VESTAL) and then used the method to obtain the source amplitude images of resting-state magnetoencephalography (MEG) signals for different frequency bands. The Fast- VESTAL technique consists of two steps. Additionally, in simulations and cases withMEG human responses, the results obtained fromusing conventional beamformer technique were compared with those from Fast-VESTAL, which highlighted the beamformer’s problems of signal leaking and distorted source time-courses.

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Figure 4. Cross correlation coefficient matrix for the 6 simulated source. (A): using ground-truth source time-courses; (B): using time-courses reconstructed by Fast-VESTAL at white-noise Level 1; (C): by Standard-VESTAL; (D): by beamformer. The coefficients under the lower-left white triangles were used to calculate the inter-source cross correlation (ICC) and their percent variance explained to the ground-truth values, as listed in Table 1.