They could gain a modest monetary reward if successful, or lose part of it if they failed. The scanner would measure how hard their brains "worked," depending upon their personal attitudes.
"Subjects who are optimists and believe they are doing well will put out the most effort, and exhibit an increase in activity in their PPC, when they expect to earn a larger reward for being successful," Richard A. Andersen, who led the team, said in releasing the study. Conversely, pessimists would show an increase when they perceived a higher level of failure.
But the researchers themselves were a little surprised when the predicted results occurred on the basis of how the subjects thought they had performed, not on their actual performance.
Does that mean optimism really didn't help? Not necessarily. Kagan pointed out that this was a very difficult task which he couldn't do himself, so perhaps the results really show that optimism has it's limitations.
That's consistent with other research showing that most of us tend to be optimistic, yet it's a mathematic certainty that most of us can't win most of the time.
Researchers at New York University, also using fMRI, found in 2007 that participants in their studies were far more likely to expect positive events in the near future than negative ones, and they saw them with "greater vividness," according to their study, published in the journal Nature. The researchers found what they believe to be a neural network that tends to make us optimistic.
"Understanding optimism is critical as optimism has been related to physical and mental health," Elizabeth Phelps of NYU said at the time. "On the other hand, pessimistic view is correlated with severity of depression symptoms."
The NYU study was reinforced last year when the University of Kansas and the Gallup World Poll released the results from surveys of 150,000 adults in more than 140 countries. The results showed that 85 percent believe the next five years will be as good or better than their current life.
"The results provide compelling evidence that optimism is a universal phenomenon," Matthew Gallagher, then a psychology doctoral candidate at the university, said in releasing the study.
That may seem astounding, given the current state of world affairs, but various research projects, including the Caltech work, suggest that optimism is deep seated in the human brain. But the Caltech research also suggests that sometimes, we may be fooling ourselves.