Saturday, October 16, 2010

Can Love Squelch Pain? Brain Research Says “Yes”

Romantic relationships, characterized by intense feelings of elation, well-being, and preoccupation with the person of affection may activate reward systems in the brain that help to counter pain. New research demonstrates that merely viewing pictures of a romantic partner can diminish the perception of pain but the clinical implications of this need further examination.

Researchers at Stanford University, Stanford, CA, and State University of New York at Stony Brook, Stony Brook, NY, tested whether pain relief evoked by viewing pictures of a romantic partner would be associated with neural activations in reward-processing centers of the brain [Younger et al. 2010]. Using functional magnetic resonance imaging (fMRI), they examined 15 individuals (8 women, 7 men, mean age=20) who were in the first 9 months of a new, romantic relationship. Participants completed 3 tasks under periods of moderate and high thermal pain: 1) viewing pictures of their romantic partner, 2) viewing pictures of an equally attractive and familiar acquaintance, and 3) a word-association distraction task previously shown to reduce pain. The painful heat stimulus was applied by an electrode attached to the palm at the base of the thumb.

BrainLovePainThe romantic partner and distraction tasks both significantly reduced self-reported pain, although only the partner task was associated with activation of reward systems in the brain. As the enhanced fMRI scan at the left shows, analgesia while viewing pictures of a romantic partner was associated with increased activity in several reward-processing regions (highlighted in yellow and red). These included portions of the frontal cortex, nucleus accumbens, and precuneus, among other areas (not shown). At the same time, there were deactivations of certain areas, such as the thalamus and supplementary motor area (shown in blue), indicating possible suppression of pain signals. Taken together, the results suggest that the activation of neural reward systems and deactivation of pain-signal-transmission centers via non-pharmacologic, psychological influences can reduce the experience of pain.

COMMENTS/CAVEATS: As might be expected, this study caught the attention of the mass media, fostering news headlines to the effect that “love conquers pain.” It makes sense that powerful emotions of euphoria, well-being, focused attention, and energy associated with love also might mobilize reward, or pleasure, centers of the brain that could counteract pain sensations, at least temporarily. However, it must be emphasized that this very small study may tell more about the experimental neurophysiology of romance in young college students than the public at large, and only during early stages of love.

Of interest, the distraction task also reduced pain but not by engaging reward systems; so, there may be an effect of strong, positive emotions associated with another person that can, indeed, help in ameliorating pain. However, the researchers concede that there was considerable individual variability in the analgesic responses of their subjects, they could not determine the specific neurophysiological system that is most critical for love-induced analgesia, and their observations might be confounded by the fact that relief of pain itself might serve as a rewarding experience. Still, patients’ relationships with loved ones in their lives, or lack thereof, may be of some clinical importance as a factor in successfully managing pain and this notion seems worthy of further consideration.

REFERENCE: Younger J, Aron A, Parke S, Chatterjee N, Mackey S. Viewing Pictures of a Romantic Partner Reduces Experimental Pain: Involvement of Neural Reward Systems. PLoS ONE. 2010;5(10): e13309 [full article here].