Decision Making and the Brain

Neuroscientists have been working to explain how people make decisions between competing alternatives. Indeed, the field of neuroeconomics has emerged as a small but potentially important field of study. Now, Harvard neuroscientists Camillo Padoa-Schioppa and John Assad have published findings in Nature, Neurons in the orbitofrontal cortex encode economic value.

Economic choice is the behaviour observed when individuals select one among many available options. There is no intrinsically ?correct? answer: economic choice depends on subjective preferences…

Theories of human and animal choice have a cornerstone in the concept of ?value?. Consider, for example, a monkey offered one raisin versus one piece of apple: behavioural evidence suggests that the animal chooses by assigning values to the two options. But where and how values are represented in the brain is unclear. Here we show that, during economic choice, neurons in the orbitofrontal cortex (OFC) encode the value of
offered and chosen goods…

Our results have broad implications for possible psychological models, suggesting that economic choice is essentially choice between goods rather than choice between actions. In this framework, neurons in the OFC seem to be a good candidate network for value assignment underlying economic choice.

The work found, for example, that monkeys who preferred grapefruit juice would select orange juice in preference to the former if there was sufficiently more orange juice offered. The researchers also showed that spatial factors (e.g., the relative position of the choices) did not affect which neurons encoded the values or on the ultimate decision.

This groundbreaking work is already drawing significant press attention, some with odd spins like, Science cracks the code of the crazy shopper and Can’t choose? Blame your brain. I guess we should be thankful that the popular press remains interested in neuroscience.

These findings will no doubt influence future work in neuroeconomics, as well as neuromarketing. How does the apparent value of a choice get assigned, and how is that value influenced by other factors? Clearly, a lengthy sales process which culminates in an unexpected purchase (e.g., a $1000 set of cookware) probably involved some kind of value manipulation during which the value of the costly items was gradually increased while that of other options (inexpensive cookware or no purchase at all) was decreased. What causes indecision, and is there a way to break out of an indecisive stalemate? I’m sure these and other questions will be eagerly pursued by neuroscientists now that they know where to look for answers.