Psycpysics Practice Qs

Question 1

When no stimulus is presented, even though observer asked

Answer 1

Blank trials

Question 2

During a VF test, the patient is reluctant to signal that she sees the stimulus even when she may see it. The threshold criteria used by the patient is

Answer 2

Strict

Question 3

When determining a clinical threshold, which psychophysical method most minimizes the important of a patients criterion?

Answer 3

Forced choice

Question 4

Which method of threshold determination is commonly used during automated VF testing?

Answer 4

Staircase

Question 5

Which of the following forced-choice clinical procedures is expected to result in the least steep (shallowest) psychometric function

Answer 5

2AFC

Question 6

A response in which the subject reports not seeing a clearly visible, Supra-threshold stimulus is referred to as a

Answer 6

False negative

Question 7

The Jackson crossed cylinder tests for measuring astigmatism is an example of which fo the following psychophysical methods

Answer 7

Forced choice

Question 8

If the chance performance of an 4AFC method experiment is 25% what is the threshold of this 4AFC method?

Answer 8

62.5

Question 9

When a patient adopts a strict criterion during clinical test, as opposed to a lax criterion, the result is relatively

Answer 9

Few false positives and few hits

Question 10

If the VA of a patient who has a strict criterion is determined with the endothelium of descending limits alone, the measure VA is likely to be

Answer 10

Betterthan it actually is

Question 11

Ocular disease is expected to cause the slope of the psychometric function to

Answer 11

Decrease

Question 12

Webers law predicts that as background intensity increases, contrast threshold

Answer 12

Remains constant

Question 13

When measuring VA with a typical snellen VA test, which psychophysical methods will provide the most reliable result

Answer 13

Descending limit

Combined with forced choice

Question 14

As the intensity of the background surrounding a patch of light increases, the background of the patch

Answer 14

Decreases

Question 15

According to signal detection theory, a stimulus produces neural activity that is

Answer 15

Randomly distributed over time

Question 16

For a given detecatblilty, as the probability of a hit increases, the probability of a false positive

Answer 16

Increases

Question 17

The method of constant stimuli is designed to keep what constant from trial to trial

Answer 17

Subjects expectations and stimulus intensity

Question 18

As the stimulus size increases, the detectaobility of the stimulus

Answer 18

Increases

?

Question 19

The appearance of the E is the same under both dim and bright lighting conditions, as long as it obeys Weber’s law. This phenomenon is referred to as

Answer 19

Light constancy

Question 20

If an observers repsonse is correct reject, then the neural activation is

Answer 20

Below the criterion