Research › QEEG, Methods & Mechanisms
Functional mapping of electric neuronal activity with zero localization error: standardized low resolution brain electromagnetic tomography (sLORETA)
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Study at a glance
- Area
- QEEG, Methods & Mechanisms
- Study type
- Observational study
- Authors
- Pascual-Marqui RD, Esslen M, Kochi K, Lehmann D
- Journal
- 8th International Conference on Functional Mapping of the Human Brain (HBM 2002), Sendai; NeuroImage 16(2) CD-ROM supplement, poster 10003
- Year
- 2002
- Participants
- 17 subjects (empirical validation)
- Protocol
- EEG/MEG source localization (sLORETA)
Key findings
- sLORETA localized point sources exactly (zero error) in noise-free tests, with as few as 25 electrodes or sensors
- With measurement noise and suitable regularization, it had the lowest localization error of the three methods
- Shallow-to-deep source strength bias (log10 ratio) was 4.9 for minimum norm, 1.0 for Dale and 2.4 for sLORETA
- Face-viewing responses at 167 ms in 17 subjects localized to Brodmann areas 18/17 and right area 37 (fusiform gyrus)
A conference abstract introducing standardized low resolution brain electromagnetic tomography (sLORETA), a method for estimating where in the brain EEG or magnetoencephalography (MEG) signals originate. In a theoretical sphere model and in realistic head models, sLORETA was compared with the minimum norm and Dale et al. methods. It localized test sources with zero error without noise and had the lowest errors of the three with noise; a small validation in 17 people viewing faces showed expected visual and fusiform activation.