Thresholds
- Measuring Thresholds
- e.g., Forced-Choice Methods (FC)
- Set up like MOCS
- Two elements of each trial
- If spatial: two locations
- if temporal: two times
- On each trial, stimulus is randomly assigned to one of the locations/times.
- Participant is now asked where/when the stimulus occurred
- If cannot tell, must guess
- Eliminates bias
- Pure measure of sensitivity
- Method of Constant Stimuli vs. Forced-Choice
thresholds
- Forced-Choice generally lower (less intense) thresholds by a good
bit
- Example from my classes:
- Two-Point thresholds
- Method of Limits first
- FC on Method of Limits threshold (20 times)
- Students are Correct 95 to 100% of time.
- Next