Cortical Resolution Enhancement in P300 Using eLORETA Technique for BCI Construction

Individuals who suffer from severe loss of motor function but retain preserved consciousness often lose the ability to communicate with the external environment. Due to the extent of their motor impairment, these individuals are frequently unable to perform even minimal voluntary movements, further limiting their capacity to interact with others. Brain-computer interfaces (BCIs) have emerged as a promising alternative to restore this communication. However, building robust and accurate BCIs still faces several challenges, among them the low cortical resolution of electroencephalographic (EEG) signals,which, although non-invasive, tend to reflect the activation of large cortical areas—even in response to localized stimuli. This study aims to apply the Low Resolution Electromagnetic Tomography (eLORETA) technique to reconstruct the neural sources underlying EEG signals, with the goal of reducing the region of interest and improving the spatial accuracy of the estimated brain activity. Additionally, it seeks to demonstrate that the P300 event-related potential, combined with the use of high-frequency tactile stimuli, represents an efficient strategy for obtaining robust brain responses in applied contexts. Through the application of this technique to experimental data with tactile stimuli, it was possible to demonstrate that eLORETA significantly improves the localization of active brain regions, proving to be a viable tool for the development of more accurate and robust BCIs.