we’re using the staircase procedure to calculate a threshold for a visual yes-no detection task. Participants are supposed to have a 75% threshold of answering correctly. We set up the QuestHandler as described in the documentation, but when trying out the titration, we get around 100% correct instead of the desired 75%. What are we doing wrong?
Thanks in advance!
staircase = QuestHandler( startVal=0.5, startValSd=0.2, pThreshold=0.63, #because it is a one up one down staircase gamma=0.01, nTrials=100, minVal=0, maxVal=1 )
for contrast in staircase: key =  stimulus.opacity = contrast #update the difficulty or contrast from the staircase while not key: draw_stim(noise, stimulus, reddot, annulus) # draw the stimulus window.flip() key = kb.getKeys(keyList=keys) if keys in key: # if they didn't see it print("no") response = 0 staircase_means.append(staircase.mean()) else: response = 1 print("yes") staircase_means.append(staircase.mean()) staircase.addResponse(response)