PT  - JOURNAL ARTICLE
AU  - Hironori Maruyama
AU  - Natsuki Ueno
AU  - Isamu Motoyoshi
TI  - A response-locked classification image analysis of the perceptual decision making : contrast detection
AID  - 10.1101/2021.06.17.447463
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.06.17.447463
4099  - http://biorxiv.org/content/early/2021/06/17/2021.06.17.447463.short
4100  - http://biorxiv.org/content/early/2021/06/17/2021.06.17.447463.full
AB  - 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.Competing Interest StatementThe authors have declared no competing interest.