The Department of Psychology and Center for Cognitive and Brain Sciences
with support from The Delos D. Wickens Lectureship Fund
presents
Joshua Gold, Ph.D.
University of Pennsylvania
“Adaptive Decision-Making in a Dynamic World”
Many of our decisions are based on an accumulation of noisy information over time. In a dynamic world, this accumulation process must itself be adaptive, because changes can occur that render past information irrelevant to future decisions. For example, historical yields from a fruit tree that has since died no longer predict future yields. A history of stable stock prices can become irrelevant after a major change in corporate leadership. I will talk about ongoing work in my lab that has begun to identify the neural mechanisms responsible for making effective decisions in these kinds of dynamic environments. This work is based on four complementary approaches: 1) the development of an ideal-observer model to recognize and respond appropriately to environmental change-points under certain conditions, plus a systematically reduced version of the model to a simple analytic form that makes specific predictions about the underlying neural computations; 2) human psychophysics that allows us to quantify how well human performance matches predictions of our models on both perceptual and more cognitive tasks; 3) measurements of pupil diameter that allow us to test specific hypotheses about the relationship between the computations described in our models and functions of the pupil-linked arousal system; and 4) measurements of neural activity in the brainstem noradrenergic nucleus locus coeruleus, which is associated with non-luminance-mediated changes in pupil diameter, and one of its primary cortical targets, the anterior cingulate cortex (ACC), of monkeys performing change-point tasks. The results suggest that arousal systems play sophisticated computational roles in how we make effective decisions in a dynamic world.
