INTEGRATED ISING MODEL FOR DECISION MAKING IN THE BRAIN: BEYOND DRIFT-DIFFUSION

Nir Gov (Personal webpage)

Humans and other organisms make decisions choosing between optional targets, which aim to maximize the reward and minimize the cost of the outcome. The theoretical modeling of decision making has been mostly based on the drift-diffusion model, which is a successful and simple framework for explaining this process. However, new observations are challenging this model. Recently, it was found that during high cognitive load and situations of uncertainty, inhibition of neuronal firing increases, but the origin of this phenomenon is not understood. We introduce a neurophysiologically-inspired model, based on the Ising model, and include global inhibition to explore its role during the decision-making process. This model can explain how the brain may utilize inhibition to improve its decision making accuracy. Compared to experimental results, this model suggests that the regime of the brain’s activity corresponds to the vicinity of a critical state, which allows maximizing accuracy while minimizing decision time, as well as increasing accuracy with a minimal increase in inhibition.