By: Abi Lundstrom, Aric Dvorak, & Kourtney Lothspeich
Vision- Anatomy
Optic Disk (blind spot)- point where the
optic nerve exists lacking photoreceptors
leading to no vision
Eyes- globular organs used to see by
vertebrae animals
Optic Nerve- nerve that carries impulses
from the retina to the brain
Lens- flexible, elastic, transparent structure
in eye that changes shape to focus light on
the retina
Retina- innermost coating of the back of
the eye containing light sensitive receptor
cells (rods and cones)
Pupil- opening in iris that regulates amount
of light entering the eye
Rods- photoreceptor
cells sensitive to much
lower levels of light
allowing them only to
detect black and white
and are the basis for
night vision. (75 to 150
million of them)
Conesphotoreceptor cells
that require more
light than rods to
respond and detect
color
Rods and
Cones are
located in the
retina (back of
the eye)
Color deficiency,
also know as
color blindness,
affects about 8
% of American
men and less
than 1 % of
American
women. This is a
genetic condition
usually passed
from women (xx)
to their sons (xy)
Green and red are typically confused with each other
and/or blue and yellow are typically confused by color
deficient people. Some people have no sense of color
and rely only on their rods, seeing black and white
What color we
can and can’t see
We see only a portion of the
electromagnetic spectrum. We see
particular colors because objects
absorb all colors and we see the
colors that are not absorbed. For
example, a banana is yellow
because it absorbs all colors except
yellow.
Binocular fusiona composite of
the two images
we receive from
each eye.
Retinal disparitythe different
viewpoint each
eye has in the
retina. This is
crucial for our
depth perception
A large retinal disparity
(difference between the
left and right eye)
means that the object
is close. A small retinal
disparity means the
object is far.
• 20/20= perfect
eyeball objects
focused on retina
• Near sighted=
elongated eye
objects are
focused in front of
the retina
• Far sighted= to
short of an eyeball
and objects
focused behind
the retina
“Find a space with total darkness and slowly move your hand from side to
side in front of your face. What do you see?
If the answer is a shadowy shape moving past, you're probably not
imagining things. Using computerized eye trackers, a new cognitive science
study finds that at least 50% of people can see the movement of their own
hand even in the absence of all light.
Through five separate experiments involving 129 individuals, researchers
found that this eerie ability to see our hand in the dark suggests that our
brain combines information from different senses to create our
perceptions.” (Seeing in Total Darkness).
Hearing- Anatomy
Sound Waves- Vibrations of the air.
The Pinna (earflap) funnels the sound down the Auditory (ear) Canal and causes
it to vibrate which in turn vibrates the Eardrum.
Then passing from the Eardrum to the Hammer, Anvil, and Stirrup. These are tiny
bones in the middle ear that vibrate with the Eardrum and move the vibrations to
the Cochlea.
The Cochlea makes up the inner ear and contains fluids and neurons that move
with vibration. This in turn forces tiny hair-like cells to move and produce neuronal
signals.
Auditory Nerve- neuronal signals
travel through this nerve to the
brain.
This finally arrives at the cerebral
cortex where it is interpreted.
Differences in Sounds
•Decibels- The measurement of loudness of sound, amplitude,
or height of sound waves.
Decibels range from 0 to about 140 Decibels. Any sounds over 110 or
persistent sounds over 80 can be damaging to hearing.
•Pitch- The measurement
of rate of vibration (Sound
Waves).
When hearing two separate frequencies at the same time, you can still
detect both distinct pitches. Ex. Striking two keys on the piano at the same
time.
When you hear a sound, how can you locate where it came from?
This is possible because if a sound is produced on your right, it
reaches your right ear a moment sooner and is slightly louder,
signifying the direction that the sound came from.
The Doppler effect is the apparent change in frequency and wavelength of a wave
that is perceived by an observer moving relative to the source of the waves (New
World Encyclopedia).
Its why something moving towards us sounds different than the same sound
moving away from us at the same length.
Conduction Deafness- Caused by anything
hindering the physical motion before the inner
ear or the bones of the middle ear being rigid.
Sensorineural Deafness- Caused by damage
to the cochlea, hair-like cells, or auditory
neuron.
Balance
Vestibular system- regulates the body’s
sense of balance, the vestibular system is
located in the inner ear
Overstimulation: spinning, falling, and
tilting your body or head can result in
dizziness and motion sickness
Sense of balance: although you
are usually unaware of your
balance without the vestibule
system you would be unable to
stand or walk without falling.
Inertia: causes the fluid in
the canals to resist
changes in motion
Smell and Taste
Olfactory nerve: the nerve that sends
messages to the brain from the smell
receptors in the nasal passage
4 Primary sensory experiences of
taste:
• Sour
Bitter
• Salty
Sweet
Smell and Taste: They are known as
chemical senses because their
receptors are sensitive to chemical
molecules
Flavor: the combination of taste, smell, and tactile
sensations
Scientists say the human nose can detect about 10,000
different scents. Sometimes, we're not even consciously
aware of those odors. Lab studies have found that people
can tell the difference between the scents of friends and
strangers as well as between those of men and women
(Sense and Sensibility).
Relationship between smell and taste:
much of what is referred to as taste is
actually produced by the sense of smell.
For example when you have a cold your
food seems to taste bland.
Skin Senses
Receptors: receptors in the
skin provide the brain with
four kinds of information
about the environment:
• Pressure
• Warmth
• Cold
• Pain
Gate control theory of pain: the theory
that we can lessen pain by shifting our
attention away from the impulses or by
sending other signals to compete with
the pain signals
Types of pains sensation:
• Sharp localized pain you feel
immediately after the injury
• Dull generalized pain that you
may feel later.
Senses difference in environment in
relation to the skin. For example, if
you put your hand in hot water on a
hot day, you sense little or no heat.
Body Senses
Along with Visual senses, it helps
assist Vestibular system in balance
and posture.
Kinesthesis is the sense of movement
and body position.
Sensations come from receptors near
the muscles, tendons, and joints.
Kinesthetic aftereffect (n).
Any illusion involving the
kinesthetic sense in which
one kinesthetic experience
influences the next. For
example, after lifting a very
heavy weight you lift a lighter,
yet still heavy, weight that
now feels much lighter (APA
Dictionary of Psychology).
Without Kinesthetic sensations,
movements would be uncoordinated
and jerky. Thus making complex
physical activities (surgery, piano
playing, and acrobatics) impossible.
Sources
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Kasschau, R. A. (2003). Sensation and Perception. In
Understanding Psychology. Columbus, Ohio:
Glencoe/McGraw-Hill.
Doppler effect. (2006). In New World Encyclopedia.
Retrieved March 3, 2014, from
http://www.newworldencyclopedia.org/entry/Doppler_effect
Tadin, D. (2014). Seeing in Total Darkness. Science Teacher,
81(1).
Weir, K. (2010). Sense and Sensibility. Current Health Teens.
Gary, V. (2007). APA Dictionary of Psychology. Washington,
DC: American Psychological Association.