Tonic pain revalues associative memories of phasic pain

Tonic pain is proposed to adapt protective behaviours during recovery from injury. A key untested prediction of this homeostatic model is that it appropriately reshapes internal representations of phasic pain. We investigated whether lateralised tonic pain modulates phasic pain-predictive cues on that side. Using a virtual-reality Pavlovian revaluation paradigm, we assessed physiological and neural conditioned responses with EEG in theta, alpha, and beta frequency bands. Pain-predictive cues elicited neural enhanced alpha and beta suppression and increased pupil diameter during conditioning acquisition. Critically, tonic pain revalued phasic conditioned responses during extinction, with reduced midfrontal theta synchronisation when the laterality of tonic pain was congruent with predicted phasic pain. Greater tonic pain unpleasantness also enhanced posterior beta suppression for congruent cues. These findings provide evidence for an internal representation of cue-pain associations that is topographically modulated by tonic pain, suggesting that tonic pain actively reconfigures pain predictions, enabling anticipatory protective behaviours.