Lecture 1 - Signal Detection

Question 1

what is a hit

Answer 1

correct response yes when stimulus present

Question 2

what is a miss

Answer 2

responding no when stimulus is present - wrong

Question 3

what is a correct rejection

Answer 3

correctly saying no stimulus present when no stimulus is present

Question 4

what is a flase alarm

Answer 4

saying stimulus is present when it isnt

Question 5

what does stimulus above the criterion represent

Answer 5

stimulus is absent

generates misses and correct rejections

Question 6

as the criterion moves- what happens to d’

Answer 6

it stays the same- the hit/ false alarm rate shifts

Question 7

what type of error is a hit

Answer 7

correct decsion

Question 8

what type of error is a miss

Answer 8

type 2 error

Question 9

what type of error is a false alarm

Answer 9

type 1

Question 10

what type of error is a correct rejection

Answer 10

Correct decsion

Question 11

what is d prime

Answer 11

d’= measure of sensitivity to seperate noise from signal

Question 12

how is d prime measured

Answer 12

d’= seperation / spread

eg
d’= Z(hit rate)- Z(False alarm rate)

Question 13

what is a practical problem of calculating d’

Answer 13

occurs when a person detects all signals or doesnt make any false alarms

Question 14

how do you correct when a person detects all signals or doesnt make any false alarms

Answer 14

assume that a merson would have missed half a signal and would have made half a false alarm -

eg with 40 signal present trials- hit rate adjusted to 39.5/40

Question 15

according to the signal detection theory what will happen to the false alarm rate if the criterion is moved to the left

Answer 15

check this but :

think the false alarm rate will decrease and the hit rate would increase