1. The Stimulus Input: Sound Waves
Audition = hearing
Amplitude of wave
loudness
Frequency of wave
Pitch

2. Semicircular Canals

3. The Ear

4. Neural impulse to the brain

5. The Ear Perceiving Loudness
Basilar membrane’s hair cells
Compressed sound

6. The Ear Perceiving Pitch
Place theory
Frequency theory

7. Place Theory
Different hairs vibrate in the cochlea when they different pitches.
So some hairs vibrate when they hear high and other vibrate when they hear low pitches.

8. Frequency Theory
All the hairs vibrate but at different speeds.

9. The Ear Locating Sounds
Stereophonic hearing
Localization of sounds
Intensity
Speed of the sound
Demonstration volunteer

10. Nerve (sensorineural) Deafness
Conduction Deafness
Nerve (sensorineural) Deafness
Something goes wrong with the vibrations of sound on the way to the cochlea.
damage to parts of the ear itself
You can replace the bones or get a hearing aid to help.
The hair cells in the cochlea get damaged.
Loud noises can cause this type of deafness.
NO WAY to replace the hairs.
Cochlea implant is possible.

11. Cochlea and loud sounds

12. Hearing Disorders
About 28 million people have some form of hearing damage in the U.S.
Can be caused by
Injury
Infections
Explosions
Long-term exposure to loud noises
Conduction hearing loss results from damage to parts of the ear itself
Sensorineural hearing loss results when there is damage to hair cells or auditory nerve
Cochlear implants can replace damaged hair cells and transduce sounds into electrical signals sent to the auditory nerve
Use of the implants is debated
Many advocates for the deaf argue that deafness is NOT a disability, but rather an enhancement of other senses

13. This slide is intentionally left blank.
Touch
Our largest organ is ___________________
Hairy skin: contains hair cells which detect movement and pressure
Glabrous skin: no hair cells; hands, feet, lips; more sensitive
Bottom- up processing
Evidence of top-down processing
Hard to tickle yourself
Rubber hand illusion (next slide)
This slide is intentionally left blank.

14. The Skin Senses Skin is the largest sense organ
Remember Me?
Skin is the largest sense organ
There are receptors for pressure, temperature, and pain
Touch appears to be important not just as a source of information, but as a way to bond with others
Homunculus Man
Proportional representation of skin receptor concentration
The larger the part, the more receptors/the more sensitive
Demo: Skin sensitivity
“Paradoxical heat”

15. How do we feel?
Composed of four senses: warmth, pain, cold, pressure (the only one with identifiable receptors)
Warm + cold = hot
Pressure + cold= wet
Pressure + pain= tickling itch

16. Touch
Rubber hand illusion

17. Kinesthesis
Tells us where our body parts are.
Receptors located in our muscles and joints.
Sense of position and movement of your body’s parts based on sensors in your joints, tendons, bones, ears and skin.
Interacts with vision (demonstration heel to toe)
What would life be like if you lost this sense?
Vestibular sense
Based on activity in your inner ear (semicircular canals and vestibular sacs)
Tells us where our body is oriented in space.
Our sense of balance.
Located in our semicircular canals in our ears.
What happens when you spin around repeatedly? Why do we feel dizzy?

18. Vestibular Senses
Vestibular senses provide information about equilibrium and head and body position
Fluid moves in two vestibular sacs and the semicircular canals
These vestibular organs are lined with hair cells that bend when fluid moves over them
Vestibular organs are also responsible for motion sickness
Motion sickness may be caused by discrepancies between visual information and vestibular sensation

19. The pain circuit

20. Pain Understanding Pain
Biological Influences
Noiceptors - sensory receptors for pain
Gate-control theory
Ron Melzack and Patrick Wall in 1962, is the idea that physical pain is not a direct result of activation of pain receptor neurons, but rather its perception is modulated by interaction between different neurons.
-helps explain how acupuncture and electrical stimulation works. Also, why rubbing a stubbed toe helps relieve pain.
Endorphins - body’s natural morphine
Phantom limb sensations
Phantom hearing, also phantom sights and phantom tastes

21. Phantom Limb Sensation
The brain can misinterpret the
spontaneous central nervous
system activity that occurs in the
absence of normal sensory input.
Phantom limb pain is the
feeling of pain in an absent limb or a
portion of a limb

22. Pain Serves as a warning about injury or other problem
Large individual differences in pain perception
Gate control theory
Neurological “gate” in spinal cord which controls transmission of pain to brain
Major pain signals (large fiber activity) can close “gate” while small ones open it
Biopsychosocial theory
Holds that pain involves not just physical stimulus, but psychological and social factors as well
Placebo effect
Shows that when a person believes a medication reduces pain, their pain is often reduced even though no medication was given
Pain relief is likely the result of endorphin release
Alternative approaches
Hypnosis and Self-hypnosis
Acupuncture
Thought distraction

25. Controlling Pain
If you rub or shake your hand after you bang your finger, you stimulate large fibers (normal somatosensory input to the projector neurons). This closes the gate and reduces the perception of pain.

26. Pain is weird and we don’t understand it completely
Do Now: Why would it be bad not to feel pain? Do you think people who don’t feel pain have normal life expectancy? Why or why not?
Nociceptors – respond to hurtful pressure, temperature and chemicals
Placebos can relieve pain. So can hypnosis, biofeedback, physiotherapy, ultrasound, acupuncture, relaxation, electrical stimulation and massage.

27. Pain Understanding Pain
Psychological Influences
Rubber-hand illusion
Memories of pain

28. Pain Understanding Pain
Social-Cultural Influences

29. Biopsychosocial approach to pain
Gate control
theory

30. Sweet, sour, salty and bitter Taste buds
Umami
Taste buds
Chemical sense
Why are baby’s fussy with food?

31. Taste Five Basic Tastes
Traditionally, taste sensations consisted of sweet, salty, sour, and bitter tastes. Recently, receptors for a fifth taste have been discovered called “Umami” I
Jade!
Sweet
Sour
Salty
Bitter
Umami
(Fresh [dead?]
Chicken)

32. Taste Receptor cells are located in taste buds
Taste buds are located in papillae (“pa-PILL-ee”) on the tongue
Chemicals dissolve in saliva and activate taste receptors inside the taste buds
Taste is processed in the parietal lobe

33. Taste Why do we have receptors for the tastes we do?
Evolutionary perspective on how taste receptors developed?
Other aspects of taste result from the interaction of taste and smell together, such as flavors.
Without a sense of smell, our ability to distinguish flavor vanishes! 33

34. Smell Detecting common odors
Odorant binding protein (OBP) is released and attached to incoming molecules
These molecules then activate receptors in the olfactory epithelium
Axons from those receptors project directly to the olfactory bulb
Women have a better sense of smell than men
Anosmia
Complete loss of the ability to smell

35. Smell, Taste and Memory
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.

36. Smell (olfaction)