What psychophysical method was used?

What psychophysical method was used?

• A. Method of limits
• B. Method of constant stimuli
• C. Method of adjustment
• D. Signal detection theory

Answer: (B)

This item is about how to determine a detection threshold in psychophysics. The method of constant stimuli uses a fixed set of stimulus intensities that are presented in random order across many trials. By collecting responses across this range, you build a full psychometric function showing the probability of detection at each intensity, which allows a precise threshold estimate with minimal bias from the observer’s expectations or response strategy. The other approaches differ in how the stimulus is varied. The method of limits ramps the stimulus up or down to find where it is just noticeable, but it can be swayed by anticipation and a tendency to respond in a consistent direction. The method of adjustment lets the observer control the stimulus level directly until it is just detectable, which is quick but tends to be less precise due to subjective criteria and motor control. Signal detection theory, on the other hand, is a framework for analyzing detection performance to separate sensitivity from decision bias, rather than a procedure for finding a single threshold itself.

This item is about how to determine a detection threshold in psychophysics. The method of constant stimuli uses a fixed set of stimulus intensities that are presented in random order across many trials. By collecting responses across this range, you build a full psychometric function showing the probability of detection at each intensity, which allows a precise threshold estimate with minimal bias from the observer’s expectations or response strategy.

The other approaches differ in how the stimulus is varied. The method of limits ramps the stimulus up or down to find where it is just noticeable, but it can be swayed by anticipation and a tendency to respond in a consistent direction. The method of adjustment lets the observer control the stimulus level directly until it is just detectable, which is quick but tends to be less precise due to subjective criteria and motor control. Signal detection theory, on the other hand, is a framework for analyzing detection performance to separate sensitivity from decision bias, rather than a procedure for finding a single threshold itself.