Lecture 4 - Magnitude Estimation

Question 1

response expansion

Answer 1

if perceived magnitude increases faster than stimulus intensity

Question 2

response compression

Answer 2

describes magnitude increasing more slowly than stimulus intensity

Question 3

the amount of variability is too great

Answer 3

if we actually perceived everything in our environment it would overload our system

Question 4

Outside of DL (JND), how do we quantify the perceived

difference between two stimuli of different intensities?

Answer 4

• Present two stimuli (one is usually a standard with an arbitrary value), and ask the observer to assign a value to the comparison stimulus.
• Repeat the process with many comparison intensities.
• Plot the values for all the observations.

Question 5

Steven’s Power law

Answer 5

describes the relationship between the perceived magnitude and stimulus intensity for a given sense

P = KS^n
P is the perceived magnitude.
K is a constant
S is the stimulus intensity, raised to the power n

Question 6

if n > 1

Answer 6

response expansion: perceive more than is actually there

Question 7

n < 1

Answer 7

response compression: perceive less than is actually there