Time-frequency analysis for responses evoked by nociceptive and non-nociceptive stimuli based on EEG signals

Abstract: In the pursuit of a system capable of measuring pain signals in humans we propose a method to differentiate those signals related to pain from those which are not. We performed a time-frequency analysis using the Gabor transform to have complete information about the spectrum and its behaviour through the time to study the main differences over the evoked potentials provoked by both nociceptive and somatosensory (non-nociceptive) stimulation. The setup of the experiment also allowed us to study the mismatch negativity and the differences between the potentials evoked by a deviant stimulus and the ones evoked by a standard stimulus according to the roving paradigm. The results show that nociceptive evoked potentials read over the scalp have more energy than the somatosensory evoked potentials, they also differ in the frequencies that are activated as well as the latencies where such frequencies are activated. These results were obtained after pre-processing the EEG signals mainly removing the artifacts running the independent component algorithm (ICA) which allowed us to have reliable results.