Psychophysics and Measurement

Question 1

What is the goal of psychophysical measurement?

Answer 1

To measure sensation or perception w/o contamination of memory, attention or bias

Question 2

What are the 2 types of measurements for psychophysics?

Answer 2

Thresholds and Scaling

Question 3

This is known as finding the limits of sensitivity

Answer 3

Threshold

Question 4

This is known as measuring Supra threshold differences amongst stimuli

Answer 4

Scaling Techniques

Question 5

This is the smallest amount of a stimulus that is necessary to allow an observer to detect its presence

Answer 5

Perception Threshold

Question 6

This is the lowest level of tone that can be detected

Answer 6

Quiet threshold

Question 7

What are the factors that influence the meausrement of a quiet threshold?

Answer 7

1. Equipment + Testing setting
2. Subject (not under our control)
3. Stimulus Parameters (frequency + duration)
4. Measurement procedure

Question 8

What are the types of measurement procedures?

Answer 8

1. Classical Psychophysical
2. Signal Detection Theory
3. Adaptive

Question 9

Who is the father of experimental psychology who invented the classical physical procedure?

Answer 9

Gustav Theodore Fechner

Question 10

What are the 3 methods of measuring thresholds?

Answer 10

1. Method of Constant Stimuli
2. Method of Limits
3. Method of Adjustment

Question 11

This method determines the threshold by presenting observer with a set of stimuli, some above + some below threshold in a random order.

Answer 11

Method of Constant Stimuli

Question 12

Does the method of constant stimuli change the stimulus based on a patient’s responses?

Answer 12

No. There are set signals that are presented dependent of patient’s responses
- must know what the threshold should be before you start

Question 13

What percent must the patient get correct for a threshold to be determined?

Answer 13

70-80%

Question 14

The method of constant stimuli provides a complete picture of ____.

Answer 14

Sensitivity

Question 15

This method presents stimuli in a graduated scale and participants must judge the stimuli along a property that increases or decreases it

Answer 15

Method of Limits

Question 16

In the method of limits, the patient ___ the response

Answer 16

drives

Question 17

This method is the most popular test and often used with kids

Answer 17

Method of limits

Question 18

This type of trial increases a stimulus along a physical dimension

Answer 18

Ascending series trial (part of method of limits)

Question 19

This type of trial decreases the stimulus along a physical dimension.

Answer 19

Descending series trial (part of method of limits)

Question 20

How many ascending/descending trials must be completed for an average can be taken and threshold is determined?

Answer 20

5-7 trials

Question 21

In this method, the observer/subject controls the level of the stimulus and adjusts it to be at the perceptual threshold.

Answer 21

Method of Adjustment

Question 22

This method give control of the stimulus to the ___.

Answer 22

Subject

Question 23

This method is easy and intuitively appealing, but there’s no control over test time

Answer 23

Method of Adjustment

Question 24

What’s a type of method of adjustment test?

Answer 24

Bekesy testing