A new metric for analyzing single-trial event-related potentials (ERPs): application to human visual P300 delta response.

Visual P300 responses were recorded by using checkerboard-type stimuli. (1) High amplitude P300-delta responses were visible even in single trial event-related potentials (ERPs). (2) The algorithm based on the 'delta response metric' provides an efficient selection criterion for evaluation of P300 single trials in ERP ensembles. (3) The 'universal' character of the P300-delta response demonstrated in this report may open new avenues for the understanding of functional ERP components.