Uncontrollability of experimental pain decreases pain intensity and relief pleasantness ratings in a between-group design.

Introduction: A lack of control and resulting psychological helplessness can influence pain perception and learning behavior in novel situations. However, a transfer effect has not been tested directly under laboratory conditions. Objective: Combine the measurement of perceptual changes when pain is uncontrollable with the assessment of changes in learning behavior in a between-subject design informed by learned helplessness theory. Methods: In a first phase, a control group (n = 37) learned how to avoid a painful stimulus and obtain pain relief. The experimental group (n = 40) received the same sequence of painful and relieving stimuli, independent of their behavior, and thereby experienced uncontrollable pain. In a second phase, both groups could learn how to shorten a painful stimulus and induce relief. Results: Pain ratings decreased more steeply in the experimental group, where participants had no control over the stimuli. In addition, relief pleasantness ratings were lower in this group and decreased less. The groups did not differ in any measure of learning behavior. Conclusion: A lack of control over pain resulted in decreased pain and relief ratings. This reduction in perception in uncontrollable situations fits the informational value theory of pain, namely that pain is decreased, if the organism cannot act upon it.