Painful and isolated nociceptive stimuli elicit transient increases of gamma band oscillations (GBOs), maximally over the primary somatosensory cortex (S1).Because their magnitude correlates with the subjective pain intensity, GBOs have been hypothesized to reflect cortical processing involved directly in pain perception.However, when presented in isolation, nociceptive stimuli also display a graded saliency, i.e.their ability to capture attention.Hence, the correlation between GBOs and perceived pain is also compatible with an alternative interpretation, that GBOs, similarly to other features of the EEG response to painful stimuli, are not determined by pain perception per se, but reflect unspecific stimulus-triggered attentional processes.This alternative interpretation is supported by recent observations that other features of the EEG response to nociceptive input correlate with pain perception only when painful stimuli are presented in isolation, but not when equally-painful stimuli made less salient by repetition at short and constant intervals.Here, we tested whether GBOs reflect stimulus saliency or constitute an obligatory correlate of pain perception.We delivered trains of three identical laser pulses at constant 1-s inter-stimulus interval, and used four different energies to elicit graded pain intensities.Repeated-measures ANOVA combined with permutation testing revealed that, unlike the other time-frequency features of the laser-induced response, GBOs recorded over S 1 always predict the subjective pain intensity,even when the saliency content of the stimulus is reduced by repetition.Furthermore, GBOs recorded over S1 contralateral to the stimulation side causally determine those recorded over the ipsilateral side.These results provide first-time evidence that laser-induced GBOs reflect cortical activity related directly to the perception of pain.