Dear community,
I implemented a QUEST procedure from the Psychtoolbox to estimate the detection threshold for electrical stimuli. The parameter pThreshold designates the target detection rate, at which the threshold intensity should be estimated.
pThreshold is set to 0.75 and I am using a log-Weibull (Gumbel) function as the model.
After I get an estimated threshold from QUEST, I can put it back into the Gumbel function. This gives me a performance (detection rate) of 62.5% though, and not the wanted 75%.
How come the target threshold intensity is estimated independent of the pThreshold parameter? Am I getting something wrong or is there a bug in the code?
Thanks!