Do chronic pain patients 'Stroop' on pain stimuli?

Objectives. Two experiments investigating the presence of information-processing biases on tasks of attention (Stroop task) and memory (free recall) in relation to mood states in chronic pain patients are reported. The first investigates whether previously reported attentional bias is a function of pain status or mood state. The second describes a more detailed examination of the roles of anxiety and depression in processing biases in chronic pain patients. Design and method. Both studies compared interference time on an emotional Stroop task between chronic pain patients and controls. Other measures included self-report of pain, depression and anxiety. Results. Neither study found evidence for an attentional bias, although a memory recall bias was demonstrated. Conclusions. Interference in attending to emotionally salient stimuli appears to be related to measures of anxiety and depression rather than pain per se. When added to the findings of other investigators, these results suggest that the presence of attentional biases in chronic pain patients can best be accounted for as arising from mood state rather than pain-patient status.