Comparison of the power spectra in participants whose recordings cluster in C3LM but not in O1LM. Power density spectra of four representative participants are shown for derivation C3LM (left) and O1LM (right). Each participant was recorded three times resulting in three spectra (depicted in one color) per participant. The four participants shown clustered across all the three recordings for derivation C3LM but not for derivation O1LM. Note that power density is plotted on a logarithmic scale.