Human perceptual decision making of nonequilibrium fluctuations

Abstract

Perceptual decision-making frequently requires making rapid, reliable choices upon encountering noisy sensory inputs. To better define the statistical processes underlying perceptual decision-making, here we characterize the choices of human participants visualizing a system of nonequilibrium stationary physical dynamics and compare such choices to the performance of an optimal agent computing Wald's sequential probability ratio test (SPRT). Participants viewed movies of a particle endowed with drifted Brownian dynamics and had to judge the motion as leftward or rightward. Overall, the results uncovered fundamental performance limits, consistent with recently established thermodynamic trade-offs involving speed, accuracy, and dissipation. Specifically, decision times are sensitive to entropy production rates. Moreover, to achieve a given level of observed accuracy, participants require more time than predicted by SPRT, indicating suboptimal integration of available information. In view of such suboptimality, we develop an alternative account based on evidence integration with a memory time constant. Setting the time constant proportionately to the deviation from equilibrium in the stimuli significantly improved trial-by-trial predictions of decision metrics with respect to SPRT. This study shows that perceptual psychophysics using stimuli rooted in nonequilibrium physical processes provides a robust platform for understanding how the brain takes decisions on stochastic information inputs.Comment: 18 pages, 13 figure