Why do we make risky decisions?

When facing the same choice repeatedly, humans can be surprisingly inconsistent. Dopamine is a neurotransmitter known to play a role in risky decision making.  We used an MRI scanner to measure brain activity in the dopaminergic midbrain while participants made choices between safe and risky options. We showed them the next options only after waiting for activity in this area to fluctuate to a very high or a very low state. When activity was low, the brain response to the same options was higher and people were more likely to take a risk. Fluctuations in brain activity that happen as we go about our daily lives could help to explain the variability of complex human behavior.

Chew B, Hauser TU, Papoutsi M, Magerkurth J, Dolan RJ, Rutledge RB (2019) Endogenous fluctuations in the dopaminergic midbrain drive behavioral choice variability. Proceedings of the National Academy of Sciences USA 116, 18732-18737. [Abstract] [PDF] [Supplemental]

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