Attention bias modification and its impact on experimental pain outcomes: comparison of training with words versus faces in pain

Background The aim of this study was to compare the effectiveness of training participants' attention towards or away from painful faces versus pain-related words on pain outcomes on an acute experimental pain paradigm. Methods Participants were randomized to receive either training towards or away from painful faces or words. Following training, participants completed the cold pressor task. Results The results confirm that attention bias modification produced the predicted changes in attentional biases. Clear training effects were observed for words and faces, such that attentional biases changed in the predicted direction on the stimuli presented during the training. However, for those trained on words, training effects also generalized to face stimuli. As predicted, those who received training away from painful stimuli took longer to report pain (higher pain threshold) during the cold pressor task, and this effect was more pronounced for those trained on words. Contrary to expectations, those trained on faces (regardless of training direction) reported less pain than those trained on words. There were no differences between the groups for pain tolerance (length of time participants were able to keep their arms in the cold pressor). Conclusions These findings confirm that attentional biases are modifiable, and impact (in the expected manner) how quickly participants perceive pain. Further, exposure to painful faces resulted in additional benefits to the level of pain reported. However, we were unable to confirm that change in attentional biases was the mechanism of change.