Signal Detection Theory

1
Signal Detection Theory
2
Psychophysik (1860)
Stimulus
Neural activity
Perception
Neurophysiology
Inner psychophysics
outer psychophysics
3
Measuring perceptual experience

• Detection
• Identification
• Discrimination
• scaling

4
Measuring threshold

• Classical ways for perceiving a stimulus
• Method of adjustment
• Method of limits
• Method of constant stimuli

5
Psychometric function
6
Classical threshold

• T a (b-a). 50 pa/(pb-pa)

7
Objections to classical threshold

• Smooth transition
• Subliminal perception
• Response bias

8
Signal detection theory

• Sensory process Vs Decision process

9
Response bias

• Liberal response strategy
• Conservative response strategy
• Internal criterion

10
Signal detection paradigm

• Signal trials
• Noise trials

11
Response bias toward Yes
12
Response bias toward No
13
(No Transcript)
14
(No Transcript)
15
d-prime!
d Z(hit rate) Z(false alarm rate)
16
ROC curve