Exam 1 Sensation and Perception

Question 1

Sensation vs. Perception

Answer 1

Sensation= the ability to detect a stimulus
vs.
Perception= the act of giving the detected stimulus meaning

Question 2

Thresholding vs. Scaling

Answer 2

Thresholding= measuring limits of sensitivity; the stimulus that produces an arbitrary, but defined level of performance
vs.
Scaling: ordering a distributing stimuli along a perceptual dimension

Question 3

Psychophysics=

Answer 3

the branch of psychology that investigates the relationship between physical stimuli and the sensations and perception they produce

Question 4

Method of Constant Stimuli (Steps on how it works)

Answer 4

1) Choose stimuli of varying intensities
-some that you think people will always be able to perceive
-some that you think people will never be able to perceive
-some stimuli in between
2) Present each stimulis multiple times
3) Record proportion of correct responses for each intensity

Ex: Different shades of circles (L1S18)

Question 5

Pros & Cons of Method of Constant Stimuli

Answer 5

+ Easy to Administer

-Have to know what the threshold is going to be (approximately) before you start

Question 6

Method of Limits (Steps on how it works)

Answer 6

1) Start with a stimulus that can be perceived or the opposite
2) If perceivable, lower intensity
3) Continue until stimulus can’t be perceived
4) Test multiple times

Ex: Staircase/ “up-down” method (L1S21)

Question 7

Pros and Cons of Method of Limits

Answer 7

+You don’t need to know where the threshold is at the start
+Robust measure of threshold

-Spurious thresholds may be obtained without evidence that the listener was really doing the task

Question 8

Method of Adjustment (Steps on how it works)

Answer 8

1) Give subject control of the stimulus intensity
2) Instruct subject to adjust level until they can just not hear the stimulus
3) Test multiple times

Ex: Beskesy’s Tracking Method (L1S29)

Question 9

Pros and Cons of Method of Adjustment

Answer 9

+Easy/Fast
+Intuitively appealing

-Produces unreliable results

Question 10

Go No-Go assay for Measuring Thresholds

Answer 10

= measures response inhibition
-participants respond to certain stimuli (‘go” stimuli) and make no response for others (“no-go” stimuli)

Question 11

Go No-Go assay example (stimulus, response, hit, miss, correct rejection, and false alarm) on “What is the detection threshold for coffee aroma?”

Answer 11

Stimulus: coffee Response: button press
-Hit (correct): Pressing button with a Go-stimulus
-Miss(incorrect): Not pressing button with a Go-stimulus
-Correct Rejection (correct): Pressing button with a No-Go stimulus
-False Alarm (incorrect): Pressing button with a No-Go stimulus

Question 12

Two alterative force choice (2AFC) assay for measuring thresholds