RT Journal Article SR Electronic T1 Decoupling sensory from decisional choice biases in perceptual decision making JF bioRxiv FD Cold Spring Harbor Laboratory SP 062380 DO 10.1101/062380 A1 Linares, Daniel A1 Aguilar-Lleyda, David A1 López-Moliner, Joan YR 2019 UL http://biorxiv.org/content/early/2019/03/21/062380.abstract AB The contribution of sensory and decisional processes to perceptual decision making is still unclear, even in simple perceptual tasks. When decision makers need to select an action from a set of balanced alternatives, any tendency to choose one alternative more often— choice bias—is consistent with a bias in the sensory evidence, but also with a preference to select that alternative independently of the sensory evidence. To decouple sensory from decisional biases, here we asked humans to perform a simple perceptual discrimination task with two symmetric alternatives under two different task instructions. The instructions varied the response mapping between perception and the category of the alternatives. We found that from 32 participants, 30 exhibited sensory biases and 15 decisional biases. The decisional biases were consistent with a criterion change in a simple signal detection theory model. Perceptual decision making, thus, even in simple scenarios, is affected by sensory and decisional choice biases.IMPACT STATEMENT Perceptual decision making, even in simple scenarios, is affected by sensory and decisional choice biases.