Response-locked classification image analysis of perceptual decision making in contrast detection

Hironori Maruyama,Natsuki Ueno,Isamu Motoyoshi

doi:10.1038/s41598-021-02189-z

Abstract

In many situations, humans make decisions based on serially sampled information through the observation of visual stimuli. To quantify the critical information used by the observer in such dynamic decision making, we here applied a classification image (CI) analysis locked to the observer's reaction time (RT) in a simple detection task for a luminance target that gradually appeared in dynamic noise. We found that the response-locked CI shows a spatiotemporally biphasic weighting profile that peaked about 300 ms before the response, but this profile substantially varied depending on RT; positive weights dominated at short RTs and negative weights at long RTs. We show that these diverse results are explained by a simple perceptual decision mechanism that accumulates the output of the perceptual process as modelled by a spatiotemporal contrast detector. We discuss possible applications and the limitations of the response-locked CI analysis.

Highlights

In many situations, humans make decisions based on serially sampled information through the observation of visual stimuli
We found that the profile of the classification image (CI) substantially varied depending on the response time of the observer in a way that was unpredictable from the response properties of the early visual system
The present study examined the information utilization strategy adopted in dynamic decision making during stimulus observation in a simple contrast detection task

Summary

Introduction

Humans make decisions based on serially sampled information through the observation of visual stimuli. To quantify the critical information used by the observer in such dynamic decision making, we here applied a classification image (CI) analysis locked to the observer’s reaction time (RT) in a simple detection task for a luminance target that gradually appeared in dynamic noise. Neri and Heeger[18] analyzed the correlation between spatiotemporal noise and responses in each trial in a contrast detection task for luminance bars that slowly appear in dynamic noise. They found CI profiles with biphasic weights in time and space, similar to the spatiotemporal impulse response of the early visual system. Okazawa et al.[31] adopted a reverse

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Conclusion