From Stanford:

Sex sells, and recent research out from Stanford shows us how. College-aged men were shown pictures of “positive emotional stimuli” (AKA in this study as soft-core porn) while hooked up to a functional magnetic resonance imaging (fMRI) machine. The researchers found that the area of the brain associated with anticipation of reward was stimulated, and immediately afterwards these men made riskier financial decisions in a betting game.

Brian Knutson, the lead author on the study (published in Neuro Report), a lead author of the study, says “it’s all about the power of emotion and arousal and our financial decisions. The trigger doesn’t have to be sex – it could be chocolate or a winning lottery ticket.”

These cues have an emotional impact on the men, making them gamble more in the game. The implications for casinos seem obvious. Knutson hypothesized that these triggers get people to make riskier decisions- potentially leading men to play it fast and loose at the betting tables. Alcohol probably doesn’t hurt, either.

Further Reading:

Knutson, B, Wimmer, G.E., Kuhnen, C.M., and Winkielman, P. (2008) Nucleus accumbens activation mediates the influence of reward cues on financial risk taking. Neuroreport, 19.