Transient neuronal suppression for exploitation of new sensory evidence

Maxwell Shinn,John D Murray,Daeyeol Lee,Hyojung Seo

doi:10.1038/s41467-021-27697-4

Abstract

In noisy but stationary environments, decisions should be based on the temporal integration of sequentially sampled evidence. This strategy has been supported by many behavioral studies and is qualitatively consistent with neural activity in multiple brain areas. By contrast, decision-making in the face of non-stationary sensory evidence remains poorly understood. Here, we trained monkeys to identify and respond via saccade to the dominant color of a dynamically refreshed bicolor patch that becomes informative after a variable delay. Animals’ behavioral responses were briefly suppressed after evidence changes, and many neurons in the frontal eye field displayed a corresponding dip in activity at this time, similar to that frequently observed after stimulus onset but sensitive to stimulus strength. Generalized drift-diffusion models revealed consistency of behavior and neural activity with brief suppression of motor output, but not with pausing or resetting of evidence accumulation. These results suggest that momentary arrest of motor preparation is important for dynamic perceptual decision making.

Highlights

In noisy but stationary environments, decisions should be based on the temporal integration of sequentially sampled evidence
The neural activity related to the decision variable, such as that observed in lateral intraparietal cortex (LIP) and frontal eye field (FEF), shows a temporary dip after stimulus onset[11,12,13,14,15,16], and this has been interpreted as the reset of an integrator for the decision variable
Despite the general success of the generalized drift-diffusion model (GDDM) in accounting for the complex behavioral patterns observed in the reaction time (RT) and choice data, we found a behavioral feature immediately after an abrupt change in evidence which cannot be explained by the model

Summary

Introduction

In noisy but stationary environments, decisions should be based on the temporal integration of sequentially sampled evidence. Generalized driftdiffusion models revealed consistency of behavior and neural activity with brief suppression of motor output, but not with pausing or resetting of evidence accumulation These results suggest that momentary arrest of motor preparation is important for dynamic perceptual decision making. Unlike the reset or pause models, this “motor suppression” model predicts that even motor outputs unrelated to the task, such as microsaccades, might be suppressed We tested these three alternative hypotheses by analyzing the behavioral data and neural activity recorded from the FEF in monkeys performing a perceptual decision-making task in which the stimulus onset was temporally decoupled from the onset of informative stimulus evidence. These results suggest behavioral and neural signatures of motor suppression as a cognitive mechanism for the strategic use of changes in evidence during perceptual decisionmaking

Methods

Results

Conclusion