The variability between studies might
Neural Markers of Pain in Spinal Cord Injury 375
be attributed to the state of the eyes during the EEG
recordings. In fact, alpha band activity is associated with
more variability with eyes open. Individual differences,
such as the use of medications, between study subjects
might also have influenced the results. In Jensen et al.,14
Boord et al.,12 and Wydenkeller et al.,15 there were no
significant effects of medication use on the results.
However, in Vuckovic et al.,16 although medications
were continued during the recordings, their effects were
not analyzed