Thoughts of money make your brain response stronger
27 Dec 2008
Areas of the brain responsible for vision respond more strongly to objects of value like the dollar signs that cartoonists have been drawing for years, shows new research from University of California at San Diego.
The research led by John Serences, assistant professor of psychology and head of the Perception and Cognition Lab at UC San Diego, shows that past rewards influence how humans (and other animals) make decisions.
"We've known about that for a long time," said Serences, "through day-to-day experience as well as the numerous experiments of economists and cognitive psychologists. Though more and more research is looking into it, little is known about how rewards affect the way the brain processes incoming sensory information, specifically as it relates to vision. Could it be that we see things differently if they have paid off before?"
Serences examined how value affects visual processing with functional magnetic resonance imaging (fMRI), a brain-scanning technique that indirectly measures neural activity.
The brain activity of subjects was recorded as they chose between red and green targets that varied in value across the experiment. Selecting a target might yield 10 cents or nothing, potentially earning subjects making the "right" choices 10 dollars. The fMRI scans were conducted at UC Irvine.
"When a target had been valuable in the past – if selecting it had had paid off with money– the visual system represented it more strongly," Serences said. "Rewards affected information processing not just at a high level of cognitive function but right from the get-go."
"Though it is too early to say how this relates to perception," said Serences, "it raises the intriguing possibility that we see things we value more clearly – much like the way the brain responds to a bright object versus a dimly lit one."
Interestingly, changes in neural activity were better associated with the reward history of the red/green targets than with self-reported estimates of value: "It's as if the visual system is telling you how valuable something has been to you in the past," Serences said, "and telling it to you like it is, even though you can't consciously identify it."
Further research on how the brain represents the value of different objects, Serences said, could someday help us better understand how addictions influence information processing in the brain.
The mere sight of drugs or particular foods, for example, may have a larger impact on the psyches of some people. Their eyes may be on the wrong prize.
