Nonextensive entropy analysis of non-stationary ERP signals

The application of a measurement of entropy defined from the nonextensive entropy, the Tsallis-like time-dependent entropy (TDE), is proposed to investigate the event-related potential (ERPs). The TDE carries information about the degree of order or disorder associated with a multi-frequency signal response. The statistical characteristics of the TDE for different signal distributions are studied. TDE was estimated for the ERP signals recorded from several healthy subjects with a specified cognitive task. A significant decrease of entropy was correlated with the responses to target stimulus (P300). The experimental results indicate that the TDE can be employed as a quantitative measurement for monitoring the ERPs activities and other signal processing.