Neural systems responding to degrees of uncertainty in human decision-making.
Much is known about how people make decisions under varying levels of probability (risk). Less is known about the neural basis of decision-making when probabilities are uncertain because of missing information (ambiguity). In decision theory, ambiguity about probabilities should not affect choices. Using functional brain imaging, we show that the level of ambiguity in choices correlates positively with activation in the amygdala and orbitofrontal cortex, and negatively with a striatal system. Moreover, striatal activity correlates positively with expected reward. Neurological subjects with orbitofrontal lesions were insensitive to the level of ambiguity and risk in behavioral choices. These data suggest a general neural circuit responding to degrees of uncertainty, contrary to decision theory.
Hsu
Ming
M
Division of Humanities and Social Sciences, 228-77, California Institute of Technology, Pasadena, CA 91125, USA.
Bhatt
Meghana
M
Adolphs
Ralph
R
Tranel
Daniel
D
Camerer
Colin F
CF
D000328:Adult; D000679:Amygdala / Q000502:physiology; D001921:Brain / Q000502:physiology*; D001927:Brain Diseases / Q000503:physiopathology / Q000523:psychology; D001931:Brain Mapping; D016001:Confidence Intervals; D003342:Corpus Striatum / Q000502:physiology; D003657:Decision Making; D003662:Decision Theory; D005260:Female; D005625:Frontal Lobe / Q000502:physiology; D005717:Games, Experimental; D006801:Humans; D016013:Likelihood Functions; D008279:Magnetic Resonance Imaging; D008297:Male; D008606:Mental Processes; D011336:Probability; D012201:Reward; D012306:Risk; D035501:Uncertainty