Transcript Vision

PSYCHOLOGY
(8th Edition)
David Myers
PowerPoint Slides
Aneeq Ahmad
Henderson State University
Worth Publishers, © 2006
1
Sensation
Chapter 5
2
Sensation
Sensing the World:
Some Basic Principles
 Threshold
 Sensory Adaptation
Vision
 The Stimulus Input: Light Energy
 The Eye
3
Sensation
Vision
 Visual Information Processing
 Color Vision
Hearing
 The Stimulus Input: Sound Waves
 The Ear
 Hearing Loss and Deaf Culture
4
Sensation
Other Important Senses
 Touch
 Taste
 Smell
 Body Position and Movement
5
Sensation/Perception
•
•
•
•
Pulfrich Effect Demonstration
Describe what occurred
Why did you see the optical illusion?
What aspect of the demonstration
represented sensation? Perception?
6
Sensation & Perception
How do we construct our representations of the
external world?
To represent the world, we must detect physical
energy (a stimulus) from the environment and
convert it into neural signals. This is a process
called sensation.
When we select, organize, and interpret our
sensations, the process is called perception.
7
Bottom-up Processing
Analysis of the stimulus begins with the sense
receptors and works up to the level of the brain
and mind. ASSOCIATE WITH SENSATION.
Letter “A” is really a black blotch broken down into
features by the brain that we perceive as an “A.”
8
Count the f’s in the following text:
• FINISHED FILES ARE THE
RESULT OF YEARS OF
SCIENTIFIC STUDY
COMBINED WITH THE
EXEPERIENCE OF YEARS
9
Top-Down Processing
Information processing guided by higherlevel mental processes as we construct
perceptions, drawing on our experience and
expectations. ASSOCIATE WITH
PERCEPTION (schemas also)
THE CHT
10
CAN YOU READ THIS?
• Aoccdrnig to rscheearch at an Biritsh
uinervtisy, it deosn't mttaer in waht
oredr the ltteers in a wrod are. The olny
iprmoatnt tihng is taht the frist and lsat
ltteer is at the rghit pclae. The rset can
be a toatl mses and you can sitll raed it
wouthit a porbelm. Tihs is bcuseae we
do not raed ervey lteter by itslef but the
wrod as a wlohe.
•
11
Making Sense of Complexity
Our sensory and perceptual processes work
together to help us sort out complex images.
“The Forest Has Eyes,” Bev Doolittle
12
Sensing the World
Senses are nature’s gift that suit an organism’s
needs.
A frog feeds on flying insects; a male silkworm
moth is sensitive to female sex-attractant odor; and
we as human beings are sensitive to sound
frequencies that represent the range of human
voice.
13
Exploring the Senses
1.
What stimuli cross our threshold for
conscious awareness?
2.
Could we be influenced by stimuli too weak
(subliminal) to be perceived?
3.
Why are we unaware of unchanging stimuli,
like a band-aid on our skin?
14
Psychophysics
A study of the relationship between physical
characteristics of stimuli and our psychological
experience with them.
Physical World
Psychological
World
Light
Brightness
Sound
Volume
Pressure
Weight
Sugar
Sweet
15
22nd October 1850
A relative increase in
mental intensity,
[Fechner] realized,
might be measured in
terms of the relative
increase in physical
energy required to
bring it about
(Wozniak, 1999).
Gustav Fechner
(1801-1887)
16
Detection
Absolute
Threshold
Intensity
No
No
No
Yes
Yes
Observer’s Response
Detected
Tell when you (the observer) detect the light.
17
Thresholds
Proportion of “Yes” Responses
1.00
0.50
0.00
Absolute Threshold: Minimum stimulation
needed to detect a particular stimulus 50% of
the time.
0
5
10
15
20
Stimulus Intensity (lumens)
25
18
Subliminal Threshold
Subliminal Threshold:
When stimuli are below
one’s absolute threshold for
conscious awareness.
Kurt Scholz/ Superstock
19
SUBLIMINAL STIMULATION
•Subliminal = below threshold
•We can process some information from stimuli
below our absolute threshold for conscious
awareness (we can do this 50% of the time)
•The priming effect = the activation, often
unconsciously, of certain associations, thus
predisposing one’s perception, memory, or
response.
20
SUBLIMINAL MESSAGES
• Much of our information processing occurs
automatically, out of sight, off the radar screen of
our conscious mind.
• This does not mean subliminal messages work.
There is not a powerful, enduring effect on
behavior of priming. Effect is often due to the
placebo effect. (Greenwald study)
• Subliminal persuasion does not have any
powerful, enduring effect.
21
Difference Threshold
Difference Threshold: Minimum difference between
two stimuli required for detection 50% of the time,
also called just noticeable difference (JND).Increases
with the magnitude of the stimulus.
Difference
Threshold
No
No
Yes
Observer’s Response
Tell when you (observer) detect a difference in the light.
22
Weber’s Law Example
• Confirming Weber’s Law
– 40 Studies Book Example
– Quarter Examples with envelopes and tuna
cans
23
Weber’s Law
Two stimuli must differ by a constant minimum
percentage (rather than a constant amount), to be
perceived as different. Weber fraction: k = dI/I.
Stimulus
Constant (k)
Light
8%
Weight
2%
Tone
0.3%
24
WEBER’S LAW
•Weber’s Law JND = KI. To be perceived as different,
two stimuli must differ by a constant minimum
percentage.
K = constant (see chart from on previous
slide)
I = intensity
•Major principle: Our thresholds for detecting
differences are a roughly constant proportion of the size
of the original stimulus)
25
Signal Detection Theory (SDT)
Predicts how and when we detect the presence
of a faint stimulus (signal) amid background
noise (other stimulation). SDT assumes that
there is no single absolute threshold and
detection depends on:
Carol Lee/ Tony Stone Images
Person’s experience
Expectations
Motivation
Level of fatigue
26
SDT Matrix
The observer decides whether she hears the tone
or not, based on the signal being present or not.
This translates into four outcomes.
Decision
Yes
No
Present
Hit
Miss
Absent
False
Alarm
Correct Rejection
Signal
27
SIGNAL DETECTION
• Can have life or death consequences.
Example?
28
Sensory Adaptation
Diminished sensitivity as a consequence of
constant stimulation(unchanging stimulus).
Put a band aid on your arm and after awhile
you don’t sense it.
29
SENSORY ADAPTATION
• Sensory receptors are alert to novelty. Example?
• Benefit of sensory adaptation: Focus on
informative change in our environment, without
distractions of uninformative constant stimulation
• Fundamental lesson: We perceive the world not
exactly as it is, but as it is useful for us to perceive
it.
30
Now you see, now you don’t
31
Vision
32
Transduction
In sensation, the transformation of stimulus
energy into neural impulses.
TRANSDUCE = TO TRANSFORM
Phototransduction: Conversion of light energy
into neural impulses that the brain can
understand.
33
Both Photos: Thomas Eisner
The Stimulus Input: Light Energy
Visible
Spectrum
34
Light Characteristics - Visible
light is a thin slice of the
electromagnetic spectrum
1.
Wavelength (hue/color)
2.
Intensity (brightness)
3.
Saturation (purity)
35
Wavelength (Hue)
Hue (color) is
the dimension of
color determined
by the
wavelength of
the light.
Wavelength is
the distance
from the peak of
one wave to the
peak of the next.
36
Wavelength (Hue)
Violet
Indigo
400 nm
Short wavelengths
Blue
Green
Yellow
Orange
Red
700 nm
Long wavelengths
Different wavelengths of light result
in different colors(the color we experience).
37
Intensity (Brightness)
Intensity
Amount of
energy in a
wave
determined by
the amplitude.
It is related to
perceived
brightness.
38
Intensity (Brightness)
Blue color with varying levels of intensity.
As intensity increases or decreases, blue color
looks more “washed out” or “darkened.”
39
Purity (Saturation)
Saturated
Saturated
Monochromatic light added to green and red
makes them less saturated.
40
The Eye
41
Video Clip: Parts of the Eye
42
Parts of the eye
1. Cornea: Transparent tissue where light
enters the eye.
2. Iris: Muscle that expands and contracts to
change the size of the opening (pupil) for
light.
3. Lens: Focuses the light rays on the retina.
4. Retina: Contains sensory receptors (rods
and cones) that process visual information
and send it to the brain. Rods and cones
contain photopigment – chemicals that
respond to light.
43
The Lens
Lens: Transparent
structure behind the
pupil that changes shape
to focus images on the
retina.
Accommodation: The
process by which the
eye’s lens changes shape
to help focus near or far
objects on the retina.
44
The Lens
Nearsightedness: A
condition in which
nearby objects are seen
more clearly than
distant objects.
Farsightedness: A
condition in which
faraway objects are
seen more clearly than
near objects.
45
Retina
Retina: The lightsensitive inner
surface of the eye,
containing receptor
rods and cones in
addition to layers of
other neurons
(bipolar, ganglion
cells) that process
visual information.
46
Blind Spot Activity
• Can you make the circle disappear?
• What does this say about the structure
of the eye?
• Can you make the line solid?
• What does this say about the way the
brain processes information?
47
Optic Nerve, Blind Spot & Fovea
Optic nerve: Carries neural impulses from the eye to the
brain. Blind Spot: Point where the optic nerve leaves the
eye because there are no receptor cells located there. This
creates a blind spot. Fovea: Central point in the retina
around which the eye’s cones cluster, influences acuity.
http://www.bergen.org
48
Photoreceptors
E.R. Lewis, Y.Y. Zeevi, F.S Werblin, 1969
49
Video Clip: Dissection of Eye
50
Bipolar & Ganglion Cells
Bipolar cells receive messages from photoreceptors and transmit them
to ganglion cells (cells in the retina that generate action potentials
capable of traveling to brain)..
51
RETINAL PROCESSING
CONVERGENCE increases sensitivity. It is
accomplished by the bipolar cells receiving
information from many photoreceptor cells.
LATERAL INHIBITION enhances contrast.
Photoreceptor cell (rods and cones) send
information to interneuron cells and then
connections aremade between bipolar cells.
See diagram 4.11 A in textbook.
52
RETINAL PROCESSING
The axons of the ganglion cells form the optic nerve
(where it leaves the eye), a blind spot is created.
Ganglion cells have a center surround receptive
field. How the light hits the center vs the outside
helps us to see edges and contrasts between light
and dark.
53
Ganglion & Thalamic Cells
Retinal ganglion cells and thalamic neurons
break down visual stimuli into small
components and have receptive fields with
center-surround organization.
ON-center OFF-Surround
Action Potentials
54
55
Visual Information Processing
Optic nerves connect to the thalamus (specific region =
LGN the lateral geniculate nucleus) in the middle of the
brain, and the thalamus connects to the visual cortex.
56
Vision: The Brain’s Role and the Optic Chiasm
57
Feature Detection
Ross Kinnaird/ Allsport/ Getty Images
Nerve cells in the visual cortex respond to
specific features hierarchically, such as edges,
angles, and movement. Discovered by Hubel
and Wiesal – won Nobel Prize
58
Shape Detection
Ishai, Ungerleider, Martin and Haxby/ NIMH
Specific combinations of temporal lobe activity
occur as people look at shoes, faces, chairs and
houses.
59
Perception in Brain
Our perceptions are a combination of sensory
(bottom-up) and cognitive (top-down) processes.
60
Visual Information Processing
Processing of several aspects of the stimulus
simultaneously is called parallel processing (the
opposite of serial processing). The brain divides
a visual scene into subdivisions such as color,
depth, form and movement etc.
61
BRAIN PROCESSING
• The brain integrates distributed parts
and recognition occurs.
• Case studies demonstrate the effect of
distributing this process, e.g. blindsight
• D. Milner describes 2 separate visual
systems in the brain: conscious
perception and the guiding of actions
62
Tim Bieber/ The Image Bank
From Sensation to Recognition
63
COLOR VISION
• Color is a mental construction
• We “see” the color of the wavelength
that is rejected or reflected.
• The three primary colors are red, green,
and blue (all colors can be made from
these)
64
Theories of Color Vision
Trichromatic theory (YOUNG-HELMHOLTZ): Based on
behavioral experiments, Helmholtz suggested that the
retina should contain three receptors that are sensitive to
red, blue and green colors.
Standard stimulus
Comparison stimulus
Max
Medium
Low
Blue
Green
Red
65
Subtraction of Colors
If three primary
colors (pigments)
are mixed,
subtraction of all
wavelengths occurs
and the color black
is the result.
66
Addition of Colors
If three primary colors (lights) are mixed, the
wavelengths are added and the color white is
the result.
Fritz Goro, LIFE magazine, © 1971 Time Warner, Inc.
67
Photoreceptors
Blue
Cones
MacNichol, Wald
and Brown (1967)
measured directly
the absorption
spectra of visual
pigments of single
cones obtained from
the retinas of
humans.
Short
wave
Green
Cones
Medium
wave
Red
Cones
Long
wave
68
Color Blindness
Genetic disorder in which people are blind to green or
red colors. This supports the Trichromatic theory.
Ishihara Test
69
COLOR BLINDNESS
Generally male; genetically sex-linked.
Most common: red-green sensitive cones lack
function
Monochromatic or dichromatic vision is due to
malfunctioning cones (normal = trichromatic)
Website: http://www.colblindor.com/coblis-colorblindness-simulator/
70
Opponent Colors
Gaze at the middle of the flag for about 30
Seconds. When it disappears, stare at the dot and report
whether or not you see Britain's flag.
71
Opponent Process Theory
Hering proposed that we process four
primary colors combined in pairs of redgreen, blue-yellow, and black-white.
Cones
Retinal
Ganglion
Cells 72
OPPONENT PROCESS
THEORY
AFTER leaving the receptor cells, visual information is
analyzed in terms of opposite colors
Occurs in retina and thalamus, after leaving receptor
cells (cones)
Red-green, blue-yellow, black-white
This explains: afterimages, colorblindness
73
Color Constancy
Color of an object remains the same under different
illuminations. However, when context changes the
color of an object may look different.
Fundamental point: comparisons govern our
perceptions.
R. Beau Lotto at University College, London
74
SUMMARY
Color processing has two stages.
The retina’s red, green, and blue cones
respond to different color stimuli in different
ratios (Trichromatic Theory).
Then, the nervous system’s ganglion cells with
their center surround feature process
information on its way to the visual cortex
(Opponent-Process Theory) . Afterimage
demonstrates
75
VISUAL CAPTURE
• How important is vision?
• Is vision more important than the other
senses?
76
Audition
HEARING IS HIGHLY ADAPTIVE.
EXAMPLE?
77
The Stimulus Input: Sound
Waves
Sound waves are composed of compression and
rarefaction of air molecules.
Acoustical transduction: Conversion of sound
waves into neural impulses in the hair cells of the
inner ear.
78
Sound Characteristics
1.
2.
3.
Frequency (pitch)
Intensity (loudness)
Quality (timbre)
79
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.
80
Intensity (Loudness)
Intensity
(Loudness):
Amount of energy
in a wave,
determined by the
amplitude, relates
to the perceived
loudness.
81
Loudness of Sound
Richard Kaylin/ Stone/ Getty Images
120dB
82
70dB
Quality (Timbre)
Quality (Timbre): Characteristics of sound from a
zither and a guitar allows the ear to distinguish
between the two.
http://www.1christian.net
www.jamesjonesinstruments.com
Zither
83
Guitar
Overtones
Overtones: Makes the distinction among musical
instruments possible.
84
The Ear
Dr. Fred Hossler/ Visuals Unlimited
85
The Ear
Outer Ear: Pinna. Collects sounds.
Middle Ear: Chamber between tympanic
membrane and cochlea containing three tiny
bones (ossicles =malleus, incus, stapes) that
concentrate the vibrations of the tympanic
membrane on the cochlea’s oval window.
Inner Ear: Innermost part of the ear,
containing the cochlea, semicircular canals,
and vestibular sacs.
86
Cochlea
Cochlea: Coiled, bony, fluid-filled tube in the
inner ear that transforms sound vibrations to
auditory signals.
87
Hearing—Structures and Functions of the Ear
88
AUDITION
• The cilia or hair cells, respond to ripples in the
basilar membrane. Their bending triggers
impulses in adjacent nerve fiber (forms auditory
nerve)
• Auditory nerve sends message to thalamus and
then temporal lobe’s auditory cortex
• Loudness determined by the number of activated
hair cells.
• We can lose sensitivity to loud OR soft sounds
89
Theories of Audition
Von Helmholtz’s Place Theory suggests that
sound frequencies stimulate the basilar
membrane at specific places resulting in
perceived pitch. Best explains sensing high
pitches.
http://www.pc.rhul.ac.uk
90
Theories of Audition
Frequency Theory states that the rate of nerve
impulses traveling up the auditory nerve
matches the frequency of a tone, thus enabling
us to sense its pitch.Best explains low pitches.
Sound
Frequency
Auditory Nerve
Action Potentials
100 Hz
200
91
Theories of Audition
• Volley principle: subset of Frequency
theory – Alternating firing of neural cells
allows to sense very high frequencies.
• Combination of place and frequency
theories best explains intermediate range
92
Hearing-The Brain’s Role
93
Localization of Sounds
Because we have two ears, sounds that reach
one ear faster than the other ear cause us to
localize the sound.
94
Localization of Sound
Timing and Intensity help in localizing sound
•
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.
The brain uses parallel processing - processing
timing differences and intensity differences as
well as other features of sound such as contrast
SIMULTANEOUSLY
95
Hearing Loss
Conduction Hearing Loss: Hearing loss caused
by damage to the mechanical system that
conducts sound waves to the cochlea.
Sensorineural Hearing Loss Hearing loss caused
by damage to the cochlea’s receptor cells or to
the auditory nerve, also called nerve deafness.
96
Hearing Deficits
Older people tend to hear low frequencies well but
suffer hearing loss when listening for high
frequencies.
97
NERVE DEAFNESS
• Often linked to heredity, aging and prolonged
exposure to loud sounds
• These tissues cannot be regenerated once dead
• Digital hearing aids amplify vibrations for certain
frequencies and compressing sound (amplifying
soft sounds) Little help for nerve deafness
98
Deaf Culture
Cochlear implants are electronic devices that
enable the brain to hear sounds.
Wolfgang Gstottner. (2004) American
Scientist, Vol. 92, Number 5. (p. 437)
EG Images/ J.S. Wilson ©
Deaf Musician
Cochlear Implant
99
DEAF CULTURE
• WHAT IS THE DEBATE WITHIN THE
DEAF COMMUNITY REGARDING THE
USE OF COCHLEAR IMPLANTS?
100
SENSORY COMPENSATION
• DEFINITION: slight enhancement of
other senses
• Example: people with aphasia (inability
to express language) are more accurate
with nonverbal cues
101
Other Important Senses
Bruce Ayers/ Stone/ Getty Images
The sense of touch (essential to development)
is a mix of four distinct skin senses—pressure,
warmth, cold, and pain.
102
Skin Senses
Only pressure has identifiable receptors. All
other skin sensations are variations of pressure,
warmth, cold and pain.
Pressure
Burning hot
Vibration
Vibration
Cold, warmth and pain
103
TOUCH AND
TEMPERATURE = SOMATIC
SENSES
• 1.The stimulus and receptors for touch
– a.when hairs on skin are bent, they deform the
skin beneath them
– b. receptors that transduce this deformation into
neural activity are in or near the skin
• 2.Some areas are more sensitive because they have
more receptors
Adaptation – change is the most important
information
104
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 (congenital insensitivity to pain (CIP), also known as
congenital analgesia)
AP Photo/ Stephen Morton
Ashley Blocker (right) feels neither pain
nor extreme hot or cold.
105
PAIN
• 1. Pain is necessary!
– a.People have different thresholds for pain;
hyperalgesia: extreme sensitivity
– b.Damage to tissue causes the release of
bradykinin, a chemical that fits into specialized
receptors in pain neurons
– c.Mylinated to carry message faster (A. Delta);
(C fibers) carry dull pain
– d. Emotional aspects of pain – knowledge of
nature of pain and when to expect it can lessen
pain
– e.Natural analgesics = endorphins and serotonin
106
Gate-Control Theory
Melzak 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
107
PAIN
– f. Gate Control Theory (Melzack and Wall):
neurological gate in spinal cord blocks pain
signals or allows them to pass on to the brain.
– g.Gate is opened by the activity of pain signals
traveling up small nerve fibers and is closed by
activity in larger fibers or by information
coming from the brain
– h.Stimulation of gate closing activity in the large
neural fibers used for pain control (rubbing
stubbed toe)
– i. Also explains brain to spinal cord messages
such as distraction and endorphins in a game or
people with high thresholds for pain
108
Pain Control
Pain can be controlled by a number of therapies
including, drugs, surgery, acupuncture, exercise,
hypnosis, and even thought distraction.
Todd Richards and Aric Vills, U.W.
©Hunter Hoffman, www.vrpain.com
109
PAIN
• The BRAIN creates pain: empathy pain, taperdown treatment
• PAIN CONTROL should be treated physically
and psychologically
• Phantom sensation: We see, hear, taste, smell,
and feel with our brain, which can sense even
without functioning senses.
• The brain misinterprets spontaneous central
nervous system activity that occurs in the absence
of normal sensory input. Examples: phantom
limb sensation (Ramachandran), tinnitus, taste
110
phantoms
PAIN CONTROL
• Contrasting pain and vision:
•
No simple neural cord running to a definable
part of the brain
•
No one type of stimulus that triggers pain
•
No special receptors for pain
•
At low intensities, stimuli that produce pain
also cause other sensations
111
Biopsychosocial Influences
112
GUSTATION (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)
113
GUSTATION
• Receptors for taste are located in the taste
buds grouped together in papillae
• 10,000 in mouth, mostly on the tongue, also
in back of tongue
114
GUSTATION
• Gustation is a chemical sense
– Taste receptor cells project hairs into pores
– Can reproduce themselves, but decrease
with age
Flavor: Smell + taste, also affected by
temperature
115
SENSORY INTERACTION
• DEFINITION: one sense may influence
another
• Examples: McGurk effect, rubber hand
illusion, synaesthesia
116
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.
117
OLFACTION (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.
118
OLFACTION
• Odors are sensed in the upper part of the nose,
where receptors detect molecules that pass into the
moisture of the lining of the nose.
• They are the only neurons which are exposed and
replace themselves
• Diminish with age, smoking, Alzheimer’s,
Parkinson’s, and alcoholism
119
OLFACTION
• Olfaction is a dual sense because we detect odors
that are either (See diagram)
•
Internal entering through the mouth, or
•
External entering through the nose
• We have particular receptors for particular smells
• Axel and Beck received the Nobel prize for
discovering receptor proteins embedded in surface
of nasal cavity
• Odors trigger a combination of receptors, then
interpreted by olfactory cortex
120
OLFACTION
• We have pain-sensitive neurons
•
Ammonia
•
Peppers
• Messages are not sent through the thalamus.
Instead goes to olfactory bulb near emotion center
of brain (limbic system). Leads to emotional
memories.
• Then to temporal lobe’s primary smell cortex and
to parts of limbic system
121
Age, Gender, and Smell
Ability to identify smell peaks during early
adulthood, but steadily declines after that. Women
are better at detecting odors than men.
122
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.
123
OLFACTION
• Smell is primitive
• Smells and social communication :
pheromones/McClintock effect = Each person has
identifiable chemical signature
• Pleasant odors can evoke pleasant memories
• Anosmia – unable to smell
124
PROPRIOCEPTION
• Sensory systems giving information
about the position of the body and what
each part is doing
• Sensorimotor co-ordination
125
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.
Bob Daemmrich/ The Image Works
http://www.heyokamagazine.com
Whirling Dervishes
Wire Walk
126
KINESTHESIA
• KINESTHESIA: where parts of your body are
with respect to each other; sensing the position
and movement of individual body parts
• information comes from receptors in joints, tendons,
and muscles then to spinal cord then to thalamus and
finally to cerebellum
• vision interacts with kinesthesia
127
VESTIBULAR SYSTEM
• Vestibular System = information about the
position and movement of the head
•
Located in Inner Ear
•
Semicircular Canals
•
Vestibular sacs - connect canals with
cochlea
•
Fluid and otoliths (crystals) on hair
128
VESTIBULAR SENSE
• Movement influences fluid in sacs and canals
• Neural connections with
• Cerebellum = balance
• ANS = affects digestive system
• Muscles of eyes (vestibular-ocular reflex)
129