Sensation and Perception

1
Sensation and Perception

• Sensation your window to the world
• Perception interpreting what comes in your
  window.

2
Transduction

• Transforming signals into neural impulses.
• Information goes from the senses to the thalamus
  , then to the various areas in the brain.

Remember Ethan in Sky High. He changes his body
to slime. Solid form to liquid form. Change
from one form of energy to another. Click the
picture to watch power placement.
3
Cocktail-party phenomenon

• The cocktail party effect describes the ability
  to focus one's listening attention on a single
  talker among a mixture of conversations and
  background noises, ignoring other conversations.
• Form of selective attention.

4
Energy v. Chemical senses

• Energy Senses

• Chemical Senses

5
Vision

• Our most dominating sense.
• Visual Capture

6
Phase One Gathering Light

• The height of a wave gives us its intensity
  (brightness).
• The length of the wave gives us its hue (color).
• ROY G BIV
• The longer the wave the more red.
• The shorter the wavelength the more violet.

7
Phase Two Getting the light in the eye
8
Phase Three Transduction
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Transduction Continued

• Order is Rods/Cones to Bipolar to Ganglion to
  Optic Nerve.
• Sends info to thalamus- area called lateral
  geniculate nucleus (LGN).
• Then sent to cerebral cortexes.
• Where the optic nerves cross is called the optic
  chiasm.

10
Phase Four In the Brain

• Goes to the Visual Cortex located in the
  Occipital Lobe of the Cerebral Cortex.
• Feature Detectors.
• Parallel Processing

We have specific cells that see the lines,
motion, curves and other features of this turkey.
These cells are called feature detectors.
11
Color Vision
Two Major Theories
12
Trichromatic Theory

• Three types of cones
• Red
• Blue
• Green
• These three types of cones can make millions of
  combinations of colors.
• Does not explain afterimages or color blindness
  well.

13
Opponent-Process theory

• The sensory receptors come in pairs.
• Red/Green
• Yellow/Blue
• Black/White
• If one color is stimulated, the other is
  inhibited.

14
Afterimages
15
Hearing
Our auditory sense
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Audition

• Audition
• the sense of hearing
• Frequency
• the number of complete wavelengths that pass a
  point in a given time
• Pitch
• a tones highness or lowness
• depends on frequency

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Hearing Sound Waves

• Auditory perception occurs when sound waves
  interact with the structures of the ear.
• Sound Wave - changes over time in the pressure of
  an elastic medium (for example, air or water).
• Without air (or another elastic medium) there can
  be no sound waves, and thus no sound

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We hear sound WAVES

• The height of the wave gives us the amplitude of
  the sound.
• The frequency of the wave gives us the pitch if
  the sound.

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Frequency of Sound Waves

• The frequency of a sound wave is measured as the
  number of cycles per second (Hertz)
• 20,000 Hz Highest Frequency we can hear
• 4,186 Hz Highest note on a piano
• 1,000 Hz Highest pitch of human voice
• 100 Hz Lowest pitch of human voice
• 27 Hz Lowest note on a piano

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The Intensity of Some Common Sounds
21
Intensity of Various Sounds
P (in sound- pressure units)
Example
Log P
Decibels
0 1 2 3 4 5 6 7 8 9
0 20 40 60 80 100 120 140 160 180
1 10 100 1000 10,000 100,000 1,000,000 10,000,000
100,000,000 1,000,000,000
Softest detectable sound Soft whisper Quiet
neighborhood Average conversation Loud music from
a radio Heavy automobile traffic Very loud
thunder Jet airplane taking off Loudest rock band
on record Spacecraft launch 9from 150 ft.)
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(No Transcript)
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Audition- The Ear

• Outer Ear
• Auditory Canal
• Eardrum
• Middle Ear
• hammer
• anvil
• stirrup
• Inner Ear
• oval window
• cochlea
• basilar membrane
• hair cells

24
Transduction in the ear

• Sound waves hit the eardrum then anvil then
  hammer then stirrup then oval window.
• Everything is just vibrating.
• Then the cochlea vibrates.
• The cochlea is lined with mucus called basilar
  membrane.
• In basilar membrane there are hair cells.
• When hair cells vibrate they turn vibrations into
  neural impulses which are called organ of Corti.
• Sent then to thalamus up auditory nerve.

It is all about the vibrations!!!
25
Pitch Theories
Place Theory and Frequency Theory
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Place Theory

• the theory that links the pitch we hear with the
  place where the cochleas membrane is stimulated
• 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.

27
Frequency Theory

• the theory that the rate of nerve impulses
  traveling up the auditory nerve matches the
  frequency of a tone, thus enabling us to sense
  its pitch
• All the hairs vibrate but at different speeds.

28
Cocktail-party phenomenon

• The cocktail party effect describes the ability
  to focus one's listening attention on a single
  talker among a mixture of conversations and
  background noises, ignoring other conversations.
• Form of selective attention.

29
Deafness

• Nerve (sensorineural) Deafness

• Conduction Deafness

• 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.

• Something goes wrong with the sound and the
  vibration on the way to the cochlea.
• You can replace the bones or get a hearing aid to
  help.

30
Audition

• Older people tend to hear low frequencies well
  but suffer hearing loss for high frequencies

31
Touch

• Receptors located in our skin.
• Gate Control Theory of Pain

32
Taste

• We have bumps on our tongue called papillae.
• Taste buds are located on the papillae (they are
  actually all over the mouth).
• Sweet, salty, sour and bitter.

33
Vestibular Sense

• Tells us where our body is oriented in space.
• Our sense of balance.
• Located in our semicircular canals in our ears.

34
Kinesthetic Sense

• Tells us where our body parts are.
• Receptors located in our muscles and joints.

Without the kinesthetic sense you could touch the
button to make copies of your buttocks.