Fig. 1.

EEG as a tool to characterize the brain’s dynamical response. a A typical EEG experiment paradigm in which discrete events are presented to the subject to elicit brain response while EEG signal is being recorded continuously. b Eliciting brain response by stimulus can be analogized to hitting a pendulum and observing its dynamic response. c The average ERP method assumes that a specific response activity is evoked by stimulus and is added to the spontaneous activity. By averaging a number of trials aligned to stimulus onsets the spontaneous activity will be cancelled out and the evoked response will remain. However, due to the trial-to-trial variability of brain response (represented by shifting blue peaks), the average ERP may end up showing a blurred version of the response pattern (bottom). d Real EEG data showing that there are different sub-components in the single trial ERPs with differential latency variabilities. The data are single trials ERP sorted by P3 latencies from electrode CPz of a single subject from a face recognition task (Rellecke et al. 2012)

This figure is taken from Ouyang (2020). Permission has been obtained