Dept of Psychology
Prefrontal computations underlying decision-making
Abstract. Damage to frontal cortex can produce a very specific deficit in decision-making. Patients make terrible life decisions and yet in all other respects their cognitive abilities are intact. My research aims to understand what computations frontal neurons perform that enable normal decision-making. We train monkeys to perform simple decision-making tasks while we record the activity of many single
neurons throughout the frontal cortex. In this talk, I will describe a series of experiments in which we have dissociated the computations performed by two subregions of the frontal cortex: the orbitofrontal cortex (OFC) and the anterior cingulate cortex (ACC).
Our results are compatible with a two-stage model of decision-making. In this model, OFC is responsible for first calculating the motivational value of sensory stimuli in the environment. This is accomplished by integrating multiple decision parameters into a single abstract measure of value. This information is then passed to ACC where it can be used to determine the value of potential actions. ACC neurons do this by incorporating information about action costs into the value signal. In addition, ACC is responsible for monitoring whether the expected outcome of the action matches the actual outcome. In this way, OFC and ACC jointly ensure that our actions are optimal with respect to realizing our motivational needs.