Transcript Example - Solon City Schools

The Eye
Energy v. Chemical senses
Energy Senses
Chemical Senses
Transduction
• Transduction -Transforming
stimulus energy (signals i.e. light
rays, sound waves etc.) into
neural impulses
• an action potential.
• Each sense has its own process
of transduction
• Information goes from the
senses to the thalamus , then to
the various areas in the brain.
• Example:
Converting Light Rays into neural
messages
Remember Ethan in Sky
High. He changes his body
to slime. Solid form to
liquid form. Transduction
is changing from one form
of energy to another.
Vision
• Our most dominating
sense.
• Visual Capture –
tendency to allow visual
images to dominate our
perception
• Example:
In a movie theater tend to
think voices are coming from
the screen, rather than the
speakers
Phase One: Gathering Light
Light reflecting off an object - The surface of
the red apple absorbs all of the colored light
rays except red. It reflects red to the eye, so
the apple is perceived as red.
The Stimulus Input: Light Energy
• Wavelength – distance
from one wave to the
next
• Determines hue (color)
Phase One: Gathering Light
HUE
• Hue - The length of the wave gives us it’s hue (color).
• ROY G BIV
Example:
• Red = longest wavelength
• Blue-violet = shortest wavelength
The Physical Property of
Waves
Intensity
•Intensity - the amount of energy in a light wave,
determined by amplitude or height
•Height of a wave gives us it’s intensity (brightness).
Example:
The higher the height, the brighter the color
•The lower the height, the duller the color
Hue and Amplitude
Phase Two: Getting the light in
the eye
The Eye
Cornea – protects the eye and bends light to provide focus
Iris – ring of muscle tissue that controls the size of the pupil
opening
Pupil – small adjustable opening in the center of the eye
which light enters
 Dilation of the pupil allows more light to reach the periphery of the
retina where the rods are located so you can see in dim light
Lens – transparent structure that focuses light onto the
retina
 Accomodation - process by which the lens changes shape (curvature
and thickness) to focus near or far images on the retina
Retina – light sensitive, inner membrane of the eye containing
rods and cones where the process of transduction occurs.
Fovea is located here.
• Rods - receptor cells
–
–
–
–
Retina
Black, white, gray sensitive
Peripheral vision
Twilight, Night vision
Most light sensitive
• Cones – receptor cells
–
–
–
–
–
Color sensitive – distinguish different wavelengths of light
central vision
Daylight, well-lit
Fine detail
Less sensitive to Dim light
• Fovea - center of the retina
– Sharp, detailed vision
– needed for reading, driving or any activity where detail is
important
– Contains only CONES
Rods versus Cones
Example: Peripheral vision and color vision
Optic Nerve
• Optic Nerve – nerve
that carries neural
impulses from the
eye to the brain
• Blind Spot – point at
which optic nerve
leaves the eye
– Blind spot = no
receptor cells
• Example:
Pg. 127 in textbook
Black dot and red car
Phase III: Transduction
Overview: cornea, iris, pupil, lens, retina,
optic nerve, thalamus, occipital lobe,
visual cortex, feature detector cells.
Transduction
1. Rods and Cones convert light energy to neural
impulses = transduction (an action potential
occurs)
2. Rods and cones synapse with neurons called
bipolar cells located in the retina
–
–
Cones hotline to the brain
Direct link between single cone to bipolar preserves fine
detail of cones message
3. Bipolar Cells transmit to ganglion cells (another
type of neuron) whose axons form the Optic
Nerve)
4. 1/2 axons in optic nerve crisscross (called optic
chasm) sending impulses to opposite side of
brain
Visual Problems
• Farsighted – cornea too
flat or distance from
cornea to retina too short
• Nearsighted – cornea too
curved or distance from
cornea to retina too long
• Astigmatism – irregularly
shaped cornea (like a
football instead of a
baseball
Rank the following from most important to least
important --What do you think is the most
important part of the eye? Why? Least
important? Why
• Cornea
• Pupil
• Iris
• Lense
• Retina
• Rods
• Cones
• Fovea
• Optic Nerve
Light wave amplitude determines
its
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1. Intensity of color
2. Color hue we
experience
3. Firing of rods in the
retina
4. Curvature and
thickness of the lens
5. Parallel processing of a
scene
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The distance from one light wave
to the next determines
Intensity
Amplitude
Hue
Absolute threshold
Transduction
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The amount of light entering the
eye is regulated by the
Lens
Iris
Retina
Optic Nerve
Feature Detectors
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Objects are brought into focus on the retina by
changes in the curvature and thickness of the
Rods and cones
Lens
Bipolar cells
Optic nerve
Cornea
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The receptor cells that convert light
energy into neural signals are called
Bipolar cells
Ganglion Cells
Rods and cones
Lens
Iris
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The most light-sensitive receptor
cells are the
Bipolar Cells
Ganglion Cells
Rods
Cones
Iris
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Phase IV: In the Brain
Example: Feature Detector
cells – allow you to see the
lines, motion, curves and
other features of this
turkey.
• Thalamus to Occipital lobe
to Visual Cortex to…
• Feature Detectors –
nerves cells in the brain
that respond to specific
features – edges, lines,
angles and movement
– Example: Turkey
• Supercell clusters – teams
of cells that fire in
response to complex
patterns
– Example: Perceiving Faces
Parallel Processing - Vision
Parallel Processing – brain simultaneously process
stimulus elements
Example: Allows you to simultaneously see the color,
form, depth, and motion of a rhino charging you
Blindsight – localized area of blindness in part of their
field of vision caused by damage to visual cortex
Example: Can’t perceive your textbook on your desk
but you can read the title
Color Vision
•Two Major Theories:
1. Trichromatic
2. Opponent Process
•Both are valid in explaining
color vision
Trichromatic Theory/
Young-Hemholtz Theory
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
Opponent-Process Theory
Opponent Process Theory - The
sensory receptors come in pairs.
• Red/Green
• Yellow/Blue
• Black/White
• If one color is stimulated, the
other is inhibited.
• Opponent process cells are
located in the thalamus
• Helps explain Color Blindness
Example:
Afterimages
Afterimages
Which of the following types of cells are
located in the brain's occipital lobe?
Rods
Cones
Ganglion Cells
Bipolar Cells
Feature Detector
Cells
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The human ability to speedily recognize
familiar objects best illustrates the value of
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1. Accomodation
2. Parallel Processing
3. Subliminal
Stimulation
4. Sensory Interaction
5. Difference
Threshold
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Experiencing a green afterimage of a red
object is most easily explained by
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1. Opponent process
theory
2. Gate control Theory
3. Place Theory
4. The Young
Helmholtz Theory
5. Frequency Theory
Hearing, Touch, Taste and
Smell
Hearing
Audition – the sense of
hearing
Frequency of Sound Waves
• Frequency - the number of the waves gives us
the pitch if the sound.
Example: short wavelength = high pitch; long
wavelength = low pitch
Amplitude of Sound Waves
• Amplitude - the height of the wave =
loudness of the sound
Example: High height = loud noise; low height
= soft noise
Absolute Threshold
• Absolute Threshold = zero
decibels
• 10 decibels = 10X increase
in sound intensity
• Example:
– A 30 decibel sound is _____
times louder than a 10
decibel sound
• 10X10 = 100
– A 40 decibel sound is _____ A rock concert is ______
times louder than a 10
times louder than normal
decibel sound
• 10X10X10 = 1000
Conversation
Parts of the Ear
Think Pair Share
• A musician is walking home alone late
one night and is startled when a dog in a
yard to his left barks unexpectedly.
Read pg. 88-89 in 5 steps book “Parts of
the Ear”
– Trace the path that the sound waves travel
as they enter the ear and proceed to
receptor cells for hearing
– Trace the path that neural impulses
created by the bark travel from the
receptor cells into the brain
Transduction
• Overview – Pinna, Auditory Canal, Eardrum, Hammer,
Anvil, Stirrup, Oval Window, Cochlea, Auditory Nerve,
Medulla, Pons, Thalamus,Temporal Lobe, Auditory Cortex
1.
Outer Ear - Pressure waves to …
Pinna, Auditory Canal, Ear Drum – tight membrane
that vibrates with sound waves. Transmits sound to
the bones of the middle ear.
2.
Middle Ear – Produces Mechanical waves from…
hammer, anvil, stirrup (ossicles) to cochlea’s oval
window
3.
Inner Ear – produces Fluid waves in…
Cochlea – coiled fluid filled tube where transduction
occurs
–
Oval window’s vibrations cause basilar membrane’s
hair cells to turn vibrations into neural impulses It is all
4.
Auditory Nerve – sends neural messages to thalamus.about the
vibrations!!!
5.
Thalamus to Temporal lobes to Auditory cortex
The structure of the ear
Mechanical vibrations triggered by sound waves are
transduced into neural impulses by _____________?
_____________ do the same job for vision as __________
do for audition
Neural impulse to the brain
Perceiving Loudness
– # of activated hair cells allows us to
perceive loudness
– If hair cells lose sensitivity to soft sounds
can still respond to loud sounds
– Compression – amplify soft sounds and not loud
• Hearing aids produce compressed sound
The loudness of a sound is
determined by what?
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1. The frequency of a
sound wave
30
2. The amplitude of a
sound wave
3. The pitch of a sound
0
wave
4. The decibel level of a
sound wave
5. The vestibular level of a
sound wave
Cones and rods are to vision as
________ are to audition.
Eardrums
Cochleas
Oval windows
Hair cells
Semicircular
canals
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Pitch Theories
Place Theory and Frequency Theory
Place Theory or Herman von
Helmholtz Theory
• Place Theory - Brain
determines pitch by
recognizing the place on
the membrane that is
generating the neural
impulse
• Best explains how we
sense high pitches
• Example: High
frequencies produce
large vibrations at
beginning of cochlear
membrane
Frequency Theory
• Frequency Theory - Brain
knows pitch by the frequency
of the neural impulse
– Frequency (speed) of sound wave
matches the speed of the neural
impulse.
• Theory limitations: Can’t
explain high pitch sounds
(neural impulses can only travel
at 1000 impulses per sec.)
• Best explains how we hear low
pitches
• Example:
Frequency of sound wave = 100
waves per second, then 100
impulses per sec. travel to the
auditory nerve
Volley Principle
• Volley PrincipleNeural cells
alternate firing in
rapid succession
• Can achieve a
combined frequency
of above 1000
waves/sec
Locating Sound
• Sound waves strike
one ear sooner and
more intensely in the
direction of the
sound
Think Pair Share
• Dog scenario again - A musician is walking
home alone late one night and is startled
when a dog in a yard to his left barks
unexpectedly.
– Using the two theories of pitch perception
explain how the brain might process the pitch of
the dog’s bark.
– Explain how the musician would know that the
bark originated to his left without even seeing
the dog.
Compare the Eye to the Ear
Eye
Frequency
Amplitude
Transduction
Receptor cells
Path to brain
Theories
Ear
Compare the Eye to the Ear
Eye
Frequency
Amplitude
Transduction
Receptor cells
Path to brain
Theories
hue
Ear
pitch
Compare the Eye to the Ear
Eye
Ear
Frequency
hue
pitch
Amplitude
Brightness
loudness
Transduction
Receptor cells
Path to brain
Theories
Compare the Eye to the Ear
Eye
Ear
Frequency
hue
pitch
Amplitude
Brightness
loudness
Transduction
Retina
Cochlea
Receptor cells
Path to brain
Theories
Compare the Eye to the Ear
Eye
Ear
Frequency
hue
pitch
Amplitude
Brightness
loudness
Transduction
Retina
Cochlea
Receptor cells
Rods and cones
Hair cells
Path to brain
Theories
Compare the Eye to the Ear
Eye
Ear
Frequency
hue
pitch
Amplitude
Brightness
loudness
Transduction
Retina
Cochlea
Receptor cells
Rods and cones
Hair cells
Path to brain
Cornea, Iris, Pupil, Lens ,
Retina, Rods and Cones,
bipolar cells, ganglion cells,
optic nerve, thalamus,
occipital lobe, visual cortex,
feature detector cells,
cerebral
cortex/supercluster cells
Pinna, auditory canal,
eardrum, hammer, anvil
stirrup, cochlea, basilar
membrane hair cells,
auditory nerve, thalamus,
temporal lobe, auditory
cortex
Theories
Compare the eye to the ear
Eye
Ear
Frequency
hue
pitch
Amplitude
Brightness
loudness
Transduction
Retina
Cochlea
Receptor cells
Rods and cones
Hair cells
Path to brain
Cornea, Iris, Pupil, Lens ,
Retina, Rods and Cones,
bipolar cells, ganglion cells,
optic nerve, thalamus,
occipital lobe, visual cortex,
feature detector cells,
cerebral
cortex/supercluster cells
Pinna, auditory canal,
eardrum, hammer, anvil
stirrup, cochlea, basilar
membrane hair cells,
auditory nerve, thalamus,
temporal lobe, auditory
cortex
Theories
Opponent-Process
Trichromatic
Frequency
Pitch
Volley principal
Deafness
Conduction Deafness • Damage to the
mechanical system that
conducts vibrations in
the middle ear (hammer,
anvil, stirrup)….or
eardrum
• You can replace the
bones or get a hearing
aid to help.
• Example:
Punctured Eardrum with
a Q-tip, Old age
Nerve (sensorineural) Deafness
• The hair cells on the basilar
membrane in the cochlea get
damaged.
• Loud noises can cause this
type of deafness.
• NO WAY to replace the hairs.
• Cochlea implant - converts
sound waves to into electrical
signals.
• Example: Old age, prolonged
exposure to loud noises
Which theory best explains how
we perceive low-pitched sounds?
1. Place theory
2. Opponent process
theory
3. Frequency Theory
4. Gate Control Theory
5. Young-Hemholtz
Theory
Touch
• Receptors located in our skin.
• Types of touch
–Pressure*
–Warmth
–Cold
–Pain
• Sensation of hot
Touch
• Tickle – stoking adjacent pressure spots
• Itching – repeated gentle stroking of a
pain spot
• Wetness – touching adjacent cold and
pressure spots
• Hot – stimulating nearby cold and warm
spots
Touch - Bottoms up AND Top
Down Processing
• Rubber hand illusion
Kinesthetic Sense
• Kinesthetic Sense Tells us where our
individual body parts
are.
• Receptors located in
our joints, tendons,
bones and ears
• Example: Playing
volleyball you know
where your limbs are
located to hit, pass,
set or run to the ball
Without the kinesthetic sense
you could not touch the button
to make copies of your buttocks.
Vestibular Sense
• Vestibular Sense Enables you to sense
your body position and
balance
• Located in our
semicircular canals in
our ears.
• Example: Spinning
around in a chair, you
lose your vestibular
sense
Taste
aka Gustatory Sense
• Sweet, sour, salty and bitter
– Umami
• Taste buds
– Chemical
• Taste is Adaptive
• Declines with age
– Smoking, alcohol
sense
Taste
• Bumps on our tongue
are called papillae.
• Taste buds are
located on the
papillae 200+ each
containing a pore.
• Pore – 50-100 taste
receptor cells that
sense food molecules
• Olfaction
Smell
– Chemical sense
– Olfactory receptors - odor
molecules fit into receptors like a
lock and key located in the olfactory
bulb
– Olfactory bulb – transmits smell from
the nose to the brain
– Olfactory nerve – sends neural
messages from the olfactory bulb
directly to the olfactory cortex in
the brain bypassing the thalamus
– Olfactory cortex – receives
information from the olfactory bulb
• Conscious awareness of odors
• Identification of odors
– Hotline between olfactory cortex and
limbic system (memory and emotion)
Smell (olfaction)
Smell and age
Sensory Interaction
• Sensory interaction –
some senses influence
others
• Examples:
Jello in the shape of a brain
looks so unappetizing, it tastes
terrible too
McGurk Effect – seeing mouth
movements for ga, but hearing
ha, we may perceive da
(saying one syllable, while hearing
another, you perceive a third)
Pain
• Biological Influences
– Nociceptors – sensory receptors that detect
hurtful temperatures, pressure or chemicals
• Located in skin, joints & tendons, organs
–
–
–
–
Gate-control theory*
Endorphins - gene
Phantom limb sensations
Tinnitus
• Psychological influences
– Distraction
– Memory of Pain – peak pain, end pain
• Socio Cultural Influences
– More pain when others experience pain
– Mirror neurons that empathize with others pain
Gate Control Theory
• Gate Control Theory – spinal cord
contains a “gate” that blocks pain signals
or allows them to pass through to the
brain
• Example:
– Opened by small nerve fibers = pain sent
– Closed by large nerve fibers = pain not sent
The pain circuit
The semicircular canals are most
directly relevant to
Hearing
Kinesthetic Sense
Pain
Vestibular Sense
Accomodation
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Alex tickles his brother by stroking
adjacent ________ spots on his skin.
Pressure
Warmth
Cold
Pain
Kinethesis
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Taste and smell are both what kind of
senses?
Vestibular
Kinesthetic
Energy
Chemical
Perceptual
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n
2
Ve
s
1
tib
ul
a
r
0%
En
er
gy
1.
2.
3.
4.
5.
20
Which theory suggests that large-fiber
activity in the spinal cord can prevent pain
signals from reaching the brain?
4
5
6
7
21
22
23
24
25
26
27
8
9
10
12
13
0%
0%
0%
Co
n
t i.
..
De
te
c
11
0%
tro
lT
Yo
...
un
gHe
lm
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lt .
..
Pl
ac
eT
he
Op
or
y
po
ne
nt
Pr
oc
e.
..
3
Ga
te
2
na
l
1
0%
Sig
1. Signal Detection
Theory
2. Gate Control Theory
3. Young-Helmholtz
Theory
4. Place Theory
5. Opponent Process
Theory
14
15
16
17
18
19
20