henry copeland:

Regret is a gambler's curse, neuroscientists say: After placing a bet, gamblers' thought processes focus on regret about past bets -- ScienceDaily

"Right after making a choice and right before finding out about the outcome, the brain is replaying and revisiting nearly every feature of what happened during the previous decision," said senior author Ming Hsu, an associate professor in the Haas School of Business and Helen Wills Neuroscience Institute at UC Berkeley. "Instead of 'I just gambled but maybe I shouldn't have,' it is, 'Last round I gambled and that was a really good choice.' Or, 'I played it safe last time but should have gone for it.'"
- www.sciencedaily.com