The Study of Perception

1
The Study of Perception

• Stimuli, Sensations vs Perceptions
• Receptors
• Transduction
• Nervous System Pathways
• Primary Processing
• Secondary Processing

2
Stimuli Sensations

• Environmental Stimuli
• Attended Stimuli
• Vision
• Hearing
• Somatosensory
• Taste
• Smell

3
Psychophysics

• Phenomenology Introspection
• Threshold Detection methods of limits,
  adjustment constant stimuli (Fechner)
• Difference Detection Methods (Weber)

4
Psychophysics

• Method of Limits

5
Psychophysics

• Method of
• Constant Stimuli
• Samples of stimuli
• are presented in
• random order
• 50 criterion

6
Psychophysics

• Method of adjustment Stimuli are adjusted by the
  subject until the stimulus is perceived.
• Method of Constant Stimuli is the most accurate

7
Psychophysics

• Difference Threshold (DL) Measurements
• The smallest difference between two stimuli that
  can be detected
• The DL increases as a function of the stimulus
  Webers Law DL/SK. K is the Weber fraction.
• K5/100.05K10/200.05

8
Psychophysics

• Magnitude Estimation (Stevens)
• Compare new stimuli to a standard and assign a
  numerical scale

9
Psychophysics

• Magnitude Estimation (Stevens)
• Response Compression (Brightness)
• Response Expansion (Electric Shock)
• Stevens Power Law PKSn

10
Receptors and Neurons

• Rods, Cones Vision
• Cilia and Hearing
• Skin Receptors and Touch
• Buds and Taste
• Bulbs and Smell