Sensation

1
Sensation

• Sensory Processing
• Vision
• Audition
• Gustation
• Olfaction
• The Somatosenses

2
Sensory Processing

• Transduction
• Sensory Coding
• Psychophysics

3
Transduction
T 6.1
4
Sensory Coding

• The codes used by the sensory systems to transmit
  information to the brain
• Two general forms
• Anatomical coding
• Temporal coding

5
Psychophysics
F 6.1
6
Psychophysics
F 6.2
7
Psychophysics
F 6.3
8
Psychophysics
F 6.4
9
Psychophysics
F 6.5
10
Vision

• Light
• The Eye and Its Functions
• Transduction of Light by Photoreceptors
• Adaptation to Light and Dark
• Eye Movements
• Color Vision

11
Light
F 6.6
12
The Eye and Its Functions
F 6.7
13
The Eye and Its Functions
F 6.8
14
The Eye and Its Functions
F 6.11
Redrawn by permission of the Royal Society and
the authors from Dowling, J. E., Boycott, B. B.
(1966). Proceedings of the Royal Society
(London), Series B, 166, 80111
15
Transduction of Light by Photoreceptors
F 6.12
16
Adaptation to Light and Dark

• When you enter a dark room after being in a
  brightly lit room or in sunlight, it takes some
  time to adjust your eyes to the dark.

17
Eye Movements

• Conjugate movements require both eyes to remain
  fixed on the same target
• Saccadic movements are abrupt shifts in gaze from
  one point to another
• Pursuit movements include tracking a moving
  object

18
Color Vision
F 6.14
19
Color Vision
F 6.15
20
Color Vision
F 6.16
21
Color Vision
F 6.17
22
Color Vision
F 6.18
23
Defects in Color Vision

• Protanopia Red cones filled with green
  photopigment
• Deuteranopia Green cones filled with red
  photopigment
• Tritanopia Lack of blue cones

24
Audition

• Sound
• The Ear and Its Functions
• Detection and Localizing Sounds in the
  Environment
• Age-Related Losses in Hearing

25
Sound
F 6.21
26
Sound
F 6.22
27
The Ear and Its Functions
F 6.23
28
The Ear and Its Functions
F 6.24
29
The Ear and Its Functions
F 6.25
30
Timbre
F 6.26
F 6.26
Stereo Review, June 1977
31
Detecting and Localizing Sounds in the Environment
F 6.27
32
Detecting and Localizing Sounds in the Environment
F 6.28
F 6.28
33
Age-Related Hearing Losses

• Sensitivity to higher frequencies declines
  earlier and with more severity than sensitivity
  to lower frequencies.
• May be harder to follow a conversation in a noisy
  room

34
Gustation

• Receptors and the Sensory Pathway
• The Five Qualities of Taste

35
Receptors and the Sensory Pathway
F 6.29
36
The Five Qualities of Taste
F 6.30

• It has been thought that there were four taste
  qualities sourness, sweetness, saltiness, and
  bitterness
• The fifth is umami which refers to the taste of
  monosodium glutamate

37
Olfaction

• Anatomy of the Olfactory System
• The Dimensions of Odor

38
Anatomy of the Olfactory System
F 6.30
39
The Dimension of Odor

• The olfactory system uses up to 1000 different
  receptor molecules
• Not yet known exactly which molecules stimulate
  which receptors
• Araneda, Kini, and Firestein (2000)

40
The Somatosenses

• The Skin Senses
• The Internal Senses
• The Vestibular Senses

41
The Skin Senses
F 6.31
42
The Skin Senses
F 6.32
43
The Internal Senses

• There are sensory receptors located in our
  internal organs, bones and joints, and muscles
  that convey painful, neutral, and in some cases
  pleasurable sensory information

44
The Vestibular Senses
F 6.33