Researchers at the University of Pennsylvania have conclusively identified a part of the brain that’s necessary for making everyday decisions about value. Previous magnetic imaging studies suggested that the ventromedial frontal cortex, or VMF, plays an evaluative role during decision-making. New research led by Joseph Kable, an assistant professor of psychology in Penn’s School of Arts and Sciences, shows that people with damaged VMF’s (victims of strokes, aneurysms, or brain tumors) are less able to choose things that are most valuable, and are also less consistent in their choices. The results were published in The Journal of Neuroscience.
From an article in ScienceDaily.com:
Kable’s experiment involved a simple questionnaire, where people with and without VMF damage were asked to pick between groupings of juice boxes and chocolate bars, based on which they liked more.
The subjects were sequentially given 11 sheets of paper, which listed two or more groups they could choose. As an incentive for them to pick the one they truly wanted more, the researchers promised to give each subject one of the 11 groups he or she selected at the end of the experiment. The subjects were also able to pick what kind of juice and chocolate they preferred before the experiment began.
While there were no price tags on any of the items, the grouped items on each sheet had a fixed value relative to one another and the total amount that could be spent. A subject could pick between a group with six juice boxes and two chocolate bars, a group with three juice boxes and three chocolate bars and a group with no juice boxes and four chocolate bars, implying that the chocolate was three times as expensive as the juice.