Evaluating users' preference for the appearance of humanoid robots via event-related potentials and spectral perturbations

Even though humanoid robots are being applied to diverse areas, the formation of users' preference for the appearance of humanoid robots remains unknown. The present study investigated users' neural dynamics underlying preference formation to evaluate users' preference for the appearance of humanoid robots. EEG signals were recorded in a preference categorisation task, and neural dynamics were analysed via event-related potentials and time-frequency analysis. The results showed that in the early stage, the preferred humanoid robot appearances elicited enhanced parieto-occipital N1, frontal P2, and early central and parieto-occipital theta rhythm power than the non-preferred appearances. In the later stage, the preferred humanoid robot appearances elicited enhanced scalp-distributed LPP and later central and parieto-occipital theta power than the non-preferred appearances. The results suggested that the formation of users' preference for the appearance of humanoid robots has a distinctive dual-stage of neural dynamics. The study provides designers with an objective method in evaluating users' preference for the appearance of humanoid robots.