Imagine an autumn day. When you leave home, you need to decide which type of jacket to wear. Looking at the sky or checking the weather forecast can help you take a guess at the weather, but this prediction is subject to uncertainty. The uncertainty in your prediction translates into uncertainty in your decision of which jacket to wear. How does the brain deal with such uncertainty when making decisions? We plan to investigate this question on two fronts. First, we will ask how brain areas responsible for selecting actions encode uncertainty about the outcome of a decision. Second, we will ask how uncertainty is decoded to form estimates of the outcomes of possible decisions. To investigate the first question, we will record the electrical activity of neurons in a brain area called the premotor cortex, working in mice. The premotor cortex has been implicated in the selection of actions. Because decisions with uncertainty involve probabilities, we will focus on evidence for how groups of neurons encode outcomes probabilistically. To investigate the second question—how uncertainty is decoded in the brain—we will record from a brain area known as the orbitofrontal cortex, which is densely connected to the premotor cortex. We believe that the uncertainty-induced variability in neuronal responses will decrease as the mouse learns to improve its estimates. To help analyze the data we collect, we will team up with a theoretical neuroscience lab that specializes in probabilistic approaches to neural coding. Our investigations will lay the groundwork for future studies that incorporate uncertainty into mathematical analyses and models. Because estimating uncertainty is a basic fact of life, our results will pave the way to understanding higher cognitive processes that are based on unreliable data, such as making a decision based on a weather forecast.
Zachary Mainen, Fundação D. Anna de Sommer Champalimaud e Dr. Carlos Montez Champalimaud
Alexandre Pouget, University of Geneva