1. Sensation
Module 15
The Other Senses
 Hearing
 Touch
 Pain
 Taste
 Smell
 Body Position and Movement

2. Hearing
The Stimulus Input: Sound Waves
Sound waves are compressing and expanding air
molecules.

3. Sound Characteristics
1. Frequency (pitch)
2. Intensity (loudness)

4. Frequency (Pitch)
Frequency (pitch):
The dimension of
frequency
determined by the
wavelength of
sound.
Wavelength: The
distance from the
peak of one wave
to the peak of the
next.

5. Intensity (Loudness)
Intensity
(Loudness):
Amount of energy
in a wave,
determined by the
amplitude, relates
to the perceived
loudness.

6. Richard Kaylin/ Stone/ Getty Images
120dB
70dB
Loudness of Sound

7. Dr. Fred Hossler/ Visuals Unlimited
The Ear

8. The Ear
Outer Ear: Collects and sends sounds to the
eardrum.
Middle Ear: Chamber between eardrum and
cochlea containing three tiny bones (hammer,
anvil, stirrup) that concentrate the vibrations
of the eardrum on the cochlea’s oval window.
Inner Ear: Innermost part of the ear,
containing the cochlea, semicircular canals,
and vestibular sacs.

9. Cochlea
Cochlea: Coiled, bony, fluid-filled tube in the
inner ear that transforms sound vibrations to
auditory signals.

10. Localization of Sounds
Because we have two ears, sounds that reach
one ear faster than the other ear cause us to
localize the sound.

11. Localization of Sound: How we
locate sound
1. Intensity differences
2. Time differences
Time differences as small as 1/100,000 of a second
can cause us to localize sound. The head acts as a
“shadow” or partial sound barrier.

12. • Show auditory transduction video clip (1)
• http://www.youtube.com/watch?v=PeTriGTENoc

13. Touch
The sense of touch is a mix of four distinct skin
senses—pressure, warmth, cold, and pain.
Bruce Ayers/ Stone/ Getty Images

14. Skin Senses
Only pressure has identifiable receptors. All other
skin sensations are variations of pressure,
warmth, cold and pain.
Pressure Vibration Vibration
Burning hot Cold, warmth and pain

15. Pain
Pain tells the body that something has gone
wrong. Usually pain results from damage to the
skin and other tissues. A rare disease exists in
which the afflicted person feels no pain.
AP Photo/ Stephen Morton
Ashley Blocker (right) feels neither pain
nor extreme hot or cold.

16. There is no one type of stimulus that triggers
pain. However, there are different
nociceptors—sensory receptors that
detect hurtful temperatures, pressure or
chemicals.

17. Biopsychosocial Influences: Our experience of pain is
much more than neural messages sent to the brain.

18. Pain: Gate-Control Theory
Melzack and Wall (1965, 1983) proposed that our
spinal cord contains neurological “gates” that
either block pain or allow it to be sensed.
Gary Comer/ PhototakeUSA.com

19. According to the gate-control theory, the spinal
cord contains a neurological “gate” that blocks
pain signals or allows them to pass. The “gate”
is opened by the activity of pain signals traveling
up small nerve fibers and is closed by activity in
larger fibers.
Based on the gate-control theory, one way to treat
chronic pain is to stimulate (massage, electric
stimulation, acupuncture) gate-closing activity in
the large neural fibers (because they close the
gate when activated).

20. Brain to spinal cord messages can also close the gate. The release of
endorphins can greatly diminish our experience of pain. (Ex: sports
injuries or vehicle accident injuries go unnoticed till some time later).
The brain can help buffer pain and it can also create pain. People who
experience phantom limb sensations is a good example. About 7 –
10 amputees may feel pain or movement in a nonexistent limb.
Similar phenomenon include phantom sounds (in people with hearing
loss) and phantom sights—nonthreatening hallucinations (in people
who have had a loss in their normal vision.
There are also phantom tastes and phantom smells.
The point to remember here is that we feel, see, hear, taste, and smell
with our brain, which can sense things even without functioning
senses.

21. Pain Control
Pain can be controlled by a number of therapies
including, drugs, surgery, acupuncture, exercise,
hypnosis, and even thought distraction.
©Hunter Hoffman, www.vrpain.com
Todd Richards and Aric Vills, U.W.

22. • Show clip on The role the brain plays in pain (2)
• http://www.youtube.com/watch?v=ldyI7mJG2EA

23. Taste Sensations
Commonly, taste sensations consist of 4
tastes. What are they?

24. Taste
Traditionally, taste sensations consisted of sweet,
salty, sour, and bitter tastes. Recently, receptors for
a fifth taste have been discovered called “Umami”.
Sweet Sour Salty Bitter Umami
(Fresh
Chicken)

25. • Taste receptors (taste buds) regenerate every 1
or 2 weeks, but age, smoking, and alcohol will
lower taste bud number and sensitivity.
• There are taste buds on the top and sides of the
tongue and in the back and on the roof of the
mouth. These taste buds contain taste receptor
cells.
• The taste receptor cells send information to an
area of the temporal lobe.

26. Sensory Interaction
When one sense affects another sense, sensory
interaction takes place. So, the taste of strawberry
interacts with its smell and its texture on the
tongue to produce flavor.

27. Smell
Like taste, smell is a chemical sense. Odorants
enter the nasal cavity to stimulate 5 million
receptors to sense smell. Unlike taste, there are
many different forms of smell.

28. Smell and Memories
The brain region for
smell (in red) is closely
connected with the
brain regions involved
with memory (limbic
system). That is why
strong memories are
made through the sense
of smell.

29. • Show video clip on olfactory sensation psychology project (4)
• http://www.youtube.com/watch?v=GP1VRpODyz4

30. Body Position and Movement
The sense of our body parts’ position and movement is called
kinesthesis. The vestibular sense monitors the head (and body’s)
position. Kinesthesis is the system for sensing the position
and movement of individual body parts. Sensors in the
muscles, tendons, and joints are continually providing our
brain with information. A companion vestibular sense
monitors the head’s (and thus the body’s) position and
movement. The biological gyroscopes for this sense of
equilibrium are in the inner ear.
http://www.heyokamagazine.com
Bob Daemmrich/ The Image Works
Whirling Dervishes Wire Walk

31. • Show clips on body position and balance (5)
• http://www.youtube.com/watch?v=BbKU0AbbARg