Scalp EEG activity shows oscillations at a variety of frequencies. This rhythmic activity divides into frequency bands, and the most commonly known bands are delta, theta, alpha, beta, and gamma. EEG frequency bands have been noted to have particular biological significance and are associated with different brain functioning states. There are still uncertainties about exactly where various frequencies are generated. However, on the contrary, there is substantial knowledge about the activated areas within the brain that generate specific spectral activity along the scalp. LORETA analysis of particular frequency bands can determine which brain regions are activated during different states or mental tasks, helping determine if the brain operates in an optimal way.

LORETA voxels are located in fixed positions within the brain's grey matter. It is always important to able to analyze the activation on single voxels and entire regions associated with specific brain functionalities, and Brodmann areas. Broadman areas are regions of the cerebral cortex that were defined at the beginning of the 20th century based on their cell organization. They were proven directly related to specific brain activities such as audition, vision, and motor functionalities.

LORETA is now a well-extended EEG analysis technique used worldwide. Its versatility, and the fact that the number of EEG channels and channel location is not fixed, make it possible to use this technique with almost every EEG sensor and experimental set-up. Furthermore, the possibility of studying both simultaneously as the voltage measured at the scalp surface and the 3D distribution of the generating electric neuronal activity.