Signal Detection Theory

Question 1

signal-detection theory provides a general _________ to describe and study _________ that are made in __________ or _________ situations

Answer 1

framework; decisions; uncertain; ambiguous

Question 2

In ‘Signal Detection Theory: The Game Show!” what was the signal?

Answer 2

a heads on the coin flip

Question 3

In ‘Signal Detection Theory: The Game Show!’ what was the noise?

Answer 3

The roll of the dice

Question 4

In ‘Signal Detection Theory: The Game Show!’ what was the total activity?

Answer 4

The combination of the coin and the die

Question 5

For signal detection theory in hearing, what is the task?

Answer 5

to detect an extremely low-level sound, the softest sound you can hear

Question 6

For signal detection theory in hearing, what is the noise? (and give 3 examples)

Answer 6

The other noise in the room (not the signal), like breathing, heartbeat, rustling of clothing

Question 7

What is the internal noise present in our auditory system?

Answer 7

some neurotransmitters are always present in the synapses and this causes spontaneous firing of auditory neurons

Question 8

The total firing rate of your ________ system is highly ________ over time, even when no _____ is present.

Answer 8

auditory; variable; sound

Question 9

There is always ________ in the amount of sound present due to the random noise.

Answer 9

variability

Question 10

When a signal is presented, the average level of activity ___________, but there is still __________ due to the noise.

Answer 10

increases; variability

Question 11

You can measure the sensitivity of the observer by the _______ between the ______ distribution and the ________+_______ distribution

Answer 11

distance; noise; signal+noise

Question 12

if the signal and noise distributions are close together (they overlap a ___) then sensitivity is ____

Answer 12

lot; low

Question 13

If the signal and noise distributions are far apart (they overlap a _____ or ___) then sensitivity is ____

Answer 13

little or none; high

Question 14

In ‘Signal Detection Theory: The Game Show’ each contestant had the same _________

Answer 14

sensitivity

Question 15

In ‘Signal Detection Theory: The Game Show’ each contestant had the same sensitivity, so why did they respond differently?

Answer 15

They had different response biases, meaning they had different criteria for responding to the same signal.

Question 16

In ‘Signal Detection Theory: The Game Show’ each contestant had different criterion, what does that mean?

Answer 16

they had different points above which they say “yes” and below which they say “no”

Question 17

different observers with the same ___________ may respond differently

Answer 17

sensitivity

Question 18

What is sensitivity?

Answer 18

The distance between the mean of the two distributions

Question 19

Criterion reflects _____

Answer 19

bias

Question 20

What is a hit rate?

Answer 20

proportion of SN distribution above criterion

Question 21

What is a miss rate?

Answer 21

proportion of SN distribution below criterion

Question 22

What is the false alarm rate?

Answer 22

proportion of N distribution above criterion

Question 23

What is the correct rejection rate?

Answer 23

proportion of N distribution below criterion

Question 24

From the ‘Signal Detection Theory: The Game Show” Contestant 1 had a _____ hit rate and a _____ false alarm rate

Answer 24

high; high

Question 25

From the ‘Signal Detection Theory: The Game Show” Contestant 2 had a ___ hit rate and a ___ false alarm rate

Answer 25

low; low

Question 26

From the ‘Signal Detection Theory: The Game Show” Contestant 3 had a pretty ____ hit rate and a relatively ____ false alarm rate

Answer 26

high; low

Question 27

Children sometimes show _______ hearing thresholds than adults. Why?

Answer 27

poorer; their response bias is different - more likely to not say yes when they aren’t completely sure

Question 28

Clinical decision theory describes the ability of a _____ to correctly ________ those ____ and ________ a ________/_________

Answer 28

test; identify; with and without; disease/disorder

Question 29

clinical decision theory is similar to signal detection theory because we are interested in:
But it is different because we are talking about the _______ of ________ ____ rather than _________ of observers in a _________________ test.

Answer 29

hits, misses, false alarms, and correct rejections; results; clinical tests; responses; psychophysical

Question 30

Is it better to have a miss (false negative) or a false alarm (false positive)?

Answer 30

A false alarm

Question 31

In clinical decision theory sensitivity is the ___ ____. It is equal to the _________ of infants with HL who did ____ ____ the hearing screening

Answer 31

hit rate; percentage; not pass

Question 32

In clinical decision theory, specificity is the correct _____ rate. it is equal to the _________ of infants with normal hearing who did ____ the hearing screening

Answer 32

rejection; percentage; pass

Question 33

If you want a test with perfect _________, make a clinical test where no one passes

Answer 33

sensitivity

Question 34

If you want a test with perfect ___________, make a test where everyone passes

Answer 34

specificity

Question 35

A good clinical test should have ___ sensitivity without sacrificing _________, and ____ specificity without sacrificing __________

Answer 35

high; specificity; high; sensitivity