Neuronal Correlates of Decision Making
The Neural Basis of Simple Economic Decision-Making
California Institute of Technology, Pasadena, USA
An essential component of every economic transaction is the subjective value computation of how much resources (e.g. energy, money) resources one is willing to give up in order to obtain a reward or to avoid experiencing a punishment (so-called goal values (GV)). Despite its pervasiveness, little is known about how the brain makes this computation. In a series of studies that employ different neuroscientific methods (e.g. functional magnetic resonance imaging (fMRI), transcranial magnetic stimulation (TMS)), we investigated the neural basis of the GV computation by scanning subjects’ brains using fMRI while they placed real bids for the right to eat liked foods or the right to avoid eating disliked foods.
We found that activity in the medial orbitofrontal cortex (mOFC) and in the dorsolateral prefrontal cortex (DLPFC) encodes subjects’ appetitive as well as aversive GV for the items. To complement these findings with causal information about the particular role both brain areas play in GV computations, we employed rTMS to subjects’ right or left DLPFC while engaging in the same food-bidding task. We found that the application of TMS to the DLPFC changes revealed preferences of our subjects.
These findings suggest an important novel mechanism of how the brain computes subjective values in order to make sound decisions that differ from the prediction and experience of aversive and appetitive values in a non decision-making context. They also have essential implications for better understanding impairments in decision-making such as addiction, obesity, compulsive behavior and anhedonic disorders like depression.
Suggested Further Readings:
Camerer C., Loewenstein G., Prelec D. Neuroeconomics:
How Neuroscience Can Inform Economics. Journal of Economic Literature XLIII, 9-64 (2005).
Glimcher, P.W. & Rustichini, A. Neuroeconomics: the consilience of brain and decision. Science 306, 447-452 (2004).
Plassmann, H., O'Doherty, J. & Rangel, A. Orbitofrontal cortex encodes willingness to pay in everyday economic transactions. J Neurosci 27, 9984-9988 (2007).
Plassmann, H., O'Doherty, J., Shiv, B. & Rangel, A. Marketing actions can modulate neural representations of experienced pleasantness. Proceedings of the National Academy of Sciences of the United States of America 105, 1050-1054 (2008).
Plassmann, H., O'Doherty, J. & Rangel, A. Activity in the medial orbitofrontal correlates negatively with aversive goal value computations (under review).
Platt, M.L. & Huettel, S.A. Risky business: the neuroeconomics of decision making under uncertainty. Nature neuroscience 11, 398-403 (2008).