Psychology
3215 - 2020 (Fluid Edition) Questions
about Psychophysics |
◔_◔
|
1. What was Fechner trying to accomplish when he founded psychophysics? From his viewpoint, what is the absolute threshold and why is it important? 2. How do you determine the absolute threshold, using the Method of Limits, the Method of Constant Stimuli, and the Method of Adjustment? How are the methods similar and how are they different? 3. Using the
Method of Constant Stimuli, explain how a psychophysical
function for the absolute threshold is produced and calculated.
4. What is a difference threshold? How are the data collected? How are the results plotted? 5. Draw the psychophysical function for a difference threshold. Be able to determine and explain the reasoning behind such terms as the Point of Subjective Equality, Upper Difference Limen, Lower Difference Limen, the Interval of Uncertainty, and the Just Noticeable Difference. 6. What is
Weber's Law? Explain the meaning of the mathematical formula. Be
able to interpret JNDs. Be able to compute a JND using Weber’s
Law. How can it be used practically? 7. What is Fechner's Law? Explain the meaning of the mathematical formula. What are the units of his scales? What does the shape of the function tell us about the fundamental relationship between perceptual experience and changes in the physical world? 8. Understand the magnitude estimation procedure and how the results from that procedure are used in Stevens' Power Law. 9. Be able to predict or interpret the meaning of various exponents derived from Stevens' Power Law on the form of the psychophysical function. How can it be used practically? 10. Compare and contrast Stevens' and Fechner’s approach to the definition of units on psychological scales. 11. Know the difference in procedures between a Signal Detection experiment and the classical absolute threshold experiment. 12. Know the matrix of possible outcomes for a trial in a Signal Detection experiment. 13. According
to Signal Detection Theory, our tendency to say "Yes, I detected
it" is controlled by our criterion or decision rule (bias, beta,
criterion) and our sensitivity to the difference between the
event being there or not (d’). Know how outcome matrices should
be examined to separate these two factors. Could a person with a
100% Hit rate be a bad detector? 14. What is a ROC plot? What is on each axis? What is the meaning of the diagonal line? Practice plotting the data you recorded in class. Practice interpreting curves and points which indicate differences in sensitivity vs. differences in strategy. 15. What is the general detection issue in detecting events like the presence of cancer or bombs?
|