Pain increases motivational drive to obtain reward, but does not affect associated hedonic responses: A behavioural study in healthy volunteers. (24th January 2013)

• Record Type: Journal Article
• Authors: Gandhi, W.; Becker, S.; Schweinhardt, P.
• Is Part Of: European journal of pain. Volume 17:Number 7(2013)
• Page Start: 1093
• Page End: 1103
• Publication Date: 2013-01-24
• Subjects: Pain -- Periodicals; Pain -- Treatment -- Periodicals; Pain -- Physiological aspects -- Periodicals; 616.0472
• DOI: 10.1002/j.1532-2149.2012.00281.x
• Languages: English
• ISSNs: 1090-3801

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <sec id="ejp281-sec-0001" sec-type="section"> <title>Background</title> <p>Pain and reward have been suggested to interact, and some evidence is provided by a rodent study showing that acutely injured animals are more motivated to reach a food reward while they do not increase food consumption, pointing at unaltered reward liking. Since no data exist in humans, we conducted a psychophysical experiment to test the effects of experimentally induced tonic pain on (1) the motivation to receive reward and (2) hedonic responses when being rewarded.</p> </sec> <sec id="ejp281-sec-0002" sec-type="section"> <title>Methods</title> <p>Forty healthy participants underwent two experimental sessions: in one, painful heat stimulation was continuously applied while participants played a monetary reward task; in the other, participants experienced non‐painful warm stimulation while playing the task. In the task, participants needed to react quickly enough to a target cue to win the money associated with the particular trial ($0.04, $1 or $4). Reaction time to the target cue served as measure of motivation. Ratings after each trial on how much the participant liked the trial's outcome served as a measure of hedonic responses.</p> </sec> <sec id="ejp281-sec-0003" sec-type="section"> <title>Results</title> <p>Pain increased the motivation to obtain reward when the incentive was high, indexed by decreased reaction times (repeated‐measures analysis of variance, <italic>interaction pain</italic> × <italic>incentive</italic>; <italic>p</italic> = 0.009). In contrast to motivational drive, hedonic ratings of the rewarding stimuli were not influenced by pain.</p> </sec> <sec id="ejp281-sec-0004" sec-type="section"> <title>Conclusion</title> <p>Similar to existing rodent data, our results suggest a pain‐induced mismatch of increased motivational drive with a lack of increased hedonic responses. This mismatch is discussed as perhaps reflecting a failed coping attempt, which is potentially relevant for chronic pain patients.</p> </sec> </abstract>