Neural systems responding to degrees of uncertainty in human decision-making

Science. 2005 Dec 9;310(5754):1680-3. doi: 10.1126/science.1115327.


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.

Publication types

  • Comment
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Amygdala / physiology
  • Brain / physiology*
  • Brain Diseases / physiopathology
  • Brain Diseases / psychology
  • Brain Mapping
  • Confidence Intervals
  • Corpus Striatum / physiology
  • Decision Making*
  • Decision Theory
  • Female
  • Frontal Lobe / physiology
  • Games, Experimental
  • Humans
  • Likelihood Functions
  • Magnetic Resonance Imaging
  • Male
  • Mental Processes*
  • Probability
  • Reward
  • Risk
  • Uncertainty*