Psychology & Neuroscience Asked by Francis on January 13, 2021
Similar to the question “How to use a QUEST staircase in 2-AFC”. I also have a question about using QUEST. In fact, I too tried to find an answer in
Psychophysics: A Practical Introduction by Kingdom & Prins; Experimental Design by Cunningham & Wallraven; Visual Psychophysics by Lu & Dosher.
Although I found a script of QUEST, it is just for the detection task, where the threshold is always the upper threshold. I want to study also the lower threshold in the discrimination task. Is anyone can give me some hints?
QUEST is one method of measuring thresholds. There are lots of other procedures including method of constant stimuli, modified up-down staircases, PEST, and ZEST. Each has their own set of requirements and own set of assumptions. If, as you say in the comments, you want to define the JND as the (25% threshold + 75% threshold)/2, then QUEST is probably not the procedure you want to use. The QUEST procedure is designed to optimally find the parameters of a psychometric function. While these parameters can give you the information you want, it is not necessarily the optimum procedure.
As it sounds like you are just learning, you may be better off with the method of constant stimuli. You present stimuli at a variety of levels, record if the answer was correct/incorrect, fit a psychometric function and then read off the values.
Answered by StrongBad on January 13, 2021
I think you may run two Quest procedures. One is used to calculate the 75% threshold and the other one calculating 25% threshold. In this way you can calculate the JND.
Answered by tongyu on January 13, 2021
Get help from others!
Recent Questions
Recent Answers
© 2024 TransWikia.com. All rights reserved. Sites we Love: PCI Database, UKBizDB, Menu Kuliner, Sharing RPP