1. Signal Detection Theory

2. Psychophysik (1860) Stimulus Perception Neural activity
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’

15. d’= Z(hit rate) – Z(false alarm rate)
d-prime!
d’= Z(hit rate) – Z(false alarm rate)

16. ROC curve