Interrelation of self-report, behavioural and electrophysiological measures assessing pain-related information processing

INTRODUCTION: A number of variables reflecting attentional and emotional mechanisms of processing pain-related information have recently attracted interest, ie, fear of pain, pain catastrophizing, hypervigilance and attentional bias to pain. These variables can be assessed by explicit measures based on conscious self-report, or by implicit measures assessing mainly preconscious stages of information processing such as behavioural or electrophysiological tests. Convergent validity within implicit measures was assumed to be high, as was the discriminant validity between implicit and explicit measures. METHOD: In the present study, two implicit measures (the dot-probe task for pain words and a word-processing task for pain words allowing event-related brain potential recordings) and three self-report measures (Pain Catastrophizing Scale, Pain Anxiety Symptoms Scale, and Pain Hypervigilance and Awareness Questionnaire) were administered to 27 healthy participants. RESULTS: No significant associations were found between the implicit measures, or between the event-related brain potentials of pain words and the explicit measures. A single significant positive correlation was found between the dot-probe pain bias and the Pain Anxiety Symptoms Scale. CONCLUSION: All variables appeared to be only weakly associated. The attempt to organize the field of variables targeting attentional and emotional mechanisms of processing pain-related information using concepts such as implicit and explicit measures failed as far as the present test on convergent/discriminant validity proved.