Research › QEEG, Methods & Mechanisms
Low resolution electromagnetic tomography: a new method for localizing electrical activity in the brain
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Study at a glance
- Area
- QEEG, Methods & Mechanisms
- Study type
- Observational study
- Authors
- Pascual-Marqui RD, Michel CM, Lehmann D
- Journal
- International Journal of Psychophysiology
- Year
- 1994
- Protocol
- LORETA source localization
Key findings
- Computes current distribution across the full brain volume without assuming a limited number of dipole sources
- Assumes neighboring neurons are activated simultaneously and synchronously, selecting the smoothest solution
- Illustrated with the visual P100 and the auditory N100, CNV (contingent negative variation) and P300 components
- Gave physiologically meaningful results where dipole solutions failed in many situations
Introduces low resolution electromagnetic tomography (LORETA), a method for estimating the three-dimensional distribution of electrical activity throughout the brain from multichannel scalp EEG. Rather than assuming a few point dipoles, it picks the smoothest possible current distribution, based on evidence that neighboring neurons fire in synchrony, giving true tomography at relatively low spatial resolution. Tested on visual and auditory evoked potential data, it gave physiologically meaningful results where one- and two-dipole fits often failed, according to the authors.