Ratio Indexes Based on Spectral Electroencephalographic Brainwaves for Assessment of Mental Involvement: A Systematic Review oleh Ilaria Marcantoni, Raffaella Assogna, Giulia Del Borrello, Marina Di Stefano, Martina Morano, Sofia Romagnoli, Chiara Leoni, Giulia Bruschi, Agnese Sbrollini, Micaela Morettini, Laura Burattini