Camillo Padoa Schioppa Research Abstract
Economic choice takes place when individuals make choices solely based on subjective preferences—for example out of a restaurant menu. Choice behavior is a traditional focus in economics and psychology, and a large body of work shows that human choices suffer from various “fallacies”. Economic choice is also important from a medical perspective, as choice deficits are often observed in patients with neurological disorders of the frontal lobe and in addiction. Research in my laboratory investigates the cognitive and neuronal mechanisms underlying economic choice. We combine behavioral, neurophysiological and computational techniques, focusing in particular on single-cell recordings in non-human primates.
Behavioral evidence indicates that economic choice entails assigning values to the available options—for example, to different items on the menu. Thus a fundamental question is how values are represented in the brain. In recent years, we found that individual neurons in the orbitofrontal cortex (OFC) encode the value monkeys assign to different juices when they choose between them. Neurons in the OFC encode the subjective value, as opposed to any physical property of the juice. The representation of value in this area is rather abstract. The activity of OFC neurons does not depend on the visuo-motor contingencies of choice, and it is invariant for changes of menu. In other words, the activity encoding the value of one particular good does not depend on what other goods are available at the same time. Such menu invariance may underlie preference transitivity, a fundamental trait of economic choice.
In our current work, we seek to address some fundamental and open questions. How does the representation of value in the OFC adapt to different behavioral contexts? Are values also represented in other brain areas, and how do neurons in OFC and other brain regions generate a decision? Can choice fallacies and choice deficits observed in frontal patients and drug addicts be explained by the neurobiology of these neuronal populations?