Figure 2. Time-frequency decomposition of the EEG responses at Cz to a control and a skin-breaking noxious stimulus in full term infants and adults.

(a–d) Median energy changes relative to baseline (−1 to −0.5 s). The colour scale is logarithmic: positive (red-yellow) and negative (blue-light blue) values respectively represent energy increases (signal synchronization) and decreases (signal desynchronization) compared to baseline. Circumscribed areas represent significant evoked activity compared to baseline. (e,f) Energy comparisons between infants and adults for noxious and control stimulus. The colour scale is logarithmic: positive (green-yellow) values represent larger energy for the infants while negative (purple-white) values represent larger energy for the adults. Circumscribed areas represent significant evoked activity differences between the two age groups. (g,h) Energy comparisons between noxious and control stimulus within the same age group. The colour scale is logarithmic: positive (green-yellow) values represent larger energy following noxious stimulation while negative (purple-white) values represent larger energy following control stimulation. Circumscribed areas represent significant evoked activity differences between the two stimuli. An approximated EEG frequency band division is displayed next to each time-frequency plot. Time-frequency regions of interest (ROIs) have been labelled and their topographical distribution is displayed to the right and at the bottom of the figure.