Attractor Decision Network with Selective Inhibition
The ability to decide swiftly and accurately in an urgent scenario is crucial for an organisms survival. The neural mechanisms underlying the perceptual decision and trade-off between speed and accuracy have been extensively studied in the past few decades. Among several theoretical models, the attractor neural network model has successfully captured both behavioral and neuronal data observed in many decision experiments. However, a recent experimental study revealed additional details that were not considered in the original attractor model. In particular, the study shows that the inhibitory neurons in the posterior parietal cortex of mice are as selective to decision making results as the excitatory neurons, whereas the previous attractor model assumes the inhibitory neurons to be unselective. In this study, we investigate the attractor model with selective inhibition (selective model), which can be considered as a general case of the previous attractor model (unselective model). Our model reproduces several behavioral and neurophysiological observations. To analyze the dynamics of the selective model, we reduce it and show that selectivity adds a time-varying component to the energy landscape. This time dependence of the energy landscape allows the selective model to integrate information carefully in initial stages, then quickly converge to an attractor once the choice is clear. This results in the selective model having a more efficient speed-accuracy trade-off that is unreachable by unselective models.