Saturday, February 26, 2011

Is Mourning Rewarding?


Light projection by Jenny Holzer
Poetry by Mahmoud Darwish (He Embraced His Murderer)


Rejection in love (Fisher et al., 2010) and complicated grief (O'Connor et al., 2008) as rewarding phenomena?

Fig. 1 (Fisher et al., 2010). Group regional activation specific to the rejector stimulus in reward systems and other areas. A: axial view. Ventral tegmental area (VTA, right arrow). The VTA regions overlap those affected when looking at a lover while happily in love (Aron et al., 2005). The cross hair (middle arrow) marks an area of activation that includes the nucleus accumbens and ventral pallidum.


Fig. 2A (O'Connor et al., 2008). Nucleus accumbens activity (10, 20, −6) in response to grief-related vs. neutral words that was significantly greater in the Complicated Grief group compared to the Noncomplicated Grief group (pictured at p < .05).


If tremendous psychological suffering and loss are associated with activity in brain regions such as the ventral tegmental area and nucleus accumbens, isn't it time to abandon the simplistic notion of dopamine as the feel-good neurotransmitter? To quote the authors of Mesolimbic Dopamine in Desire and Dread (Faure et al., 2008):
It is important to understand how mesocorticolimbic mechanisms generate positive versus negative motivations. Dopamine (DA) in the nucleus accumbens is well known as a mechanism of appetitive motivation for reward. However, aversive motivations such as pain, stress, and fear also may involve dopamine in nucleus accumbens (at least tonic dopamine signals).

References

Faure A, Reynolds SM, Richard JM, Berridge KC. (2008). Mesolimbic dopamine in desire and dread: enabling motivation to be generated by localized glutamate disruptions in nucleus accumbens. J Neurosci. 28:7184-92.

Fisher HE, Brown LL, Aron A, Strong G, Mashek D. (2010). Reward, addiction, and emotion regulation systems associated with rejection in love. J Neurophysiol. 104:51-60.

O'Connor MF, Wellisch DK, Stanton AL, Eisenberger NI, Irwin MR, Lieberman MD. (2008). Craving love? Enduring grief activates brain's reward center. Neuroimage 42:969-72.


Sample stimulus from Fig. 1 of O'Connor et al., 2008 provides an [unintentional?] example of the emotional Stroop effect.

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