Transcript Sensation and Perception

Sensation and
Perception
Chapter 4
Sensation and Perception
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ThEcOwgAvecOla
“The Cow Gave Cola”
.rat eht saw tac ehT
“The cat saw the rat” or “the cat was the rat”
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I cdnuolt bleveiee taht I cloud aulacity
uesdnatnrd waht I was rdanieg. The phaonmneal
pweor of the hmuan mnid, aoccdrnig to a
rscheearch at Cmabrigde Uinervtisy, it dseno't
mtaetr in waht oerdr the ltteres in a wrod are,
the olny iproamtnt tihng is taht the frsit and lsat
ltteer be in the rghit pclae. The rset can be a
taotl mses and you can sitll raed it whotuit a
pboerlm. Tihs is bcuseae the huamn mnid deos
not raed ervy lteter by istlef, but the wrod as a
wlohe. Azanmig huh? yaeh, and I awlyas
tghuhot slpeling was ipmorantt!
 Spps
y wrt n ntrstng stry. Spps t ws th
bst stry y hd vr wrttn. Nw tk tht splndd
stry nd rs ll th vwls. rs thm ll ntl th stry
mks n sns bcs, wll, wht s wrd
wtht vwl? spps thr r sm wrds wth n
vwl. Th wrd “my” fr nstnc hs n vwl, bt
sn’t thr syng, “nd smtms y?” stry wtht
vwls wld b cnfsng, prplxng, cmpltly
bfflng. Wld y b bl t rd t? Wld y b bl t
cmprhnd wht th stry ws syng?
Sensation and Perception
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Sensation- the process of receiving information
from the environment
Perception- the process of organizing sensory
information and making it meaningful
Absolute Threshold- the level of sensory
stimulation needed for sensation (and thus
perception) to occur
Ex. A dim light in a well light room is barely visible,
yet highly visible in a dark room
 Ex. Slight ding is barely audible in a noisy room, yet
highly audible in a quiet room
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Sensation and Perception
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Subliminal Perception (Subliminal Messages)stimulation that is below our threshold and takes place
below our level of consciousness
100
Watch clips
of movies
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Percentage
of correct
detections
75
50
Does subliminal
advertising work?
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Subliminal
stimuli
25
0
Low
Absolute
threshold
Intensity of stimulus
Medium
Sensation and Perception
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Weber’s Law- to perceive a difference between 2
stimuli, they must differ by constant proportion
Sensory Adaptation- diminished sensitivity with
constant stimulation
Ex. Smell when you walk in a restaurant
 Ex. Light in a movie theater
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Whorff Hypothesis
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Show list of colors and label the colors
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List as many words for “love” as you can
List as many words for “snow” as you can
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Whorff Hypothesis- the more words a culture has for
something, the more they perceive it
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Ex. Teenagers can think of many words for love
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Ex. Eskimos have many words– we have only a few
Sensation- Vision
Vision- sense of
seeing
White Light- light
as it originates (off
the sun or off a
bulb) before it is
broken into
different
frequencies
Vision cont
Vision cont
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Cornea- clear outer covering of the eye
Pupil- adjustable opening in the eye
black circle
 Gets larger in darkness to allow more light in, and smaller
in brightness to keep light out
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Iris- colored circular muscle that opens and closes the
pupil
Lens- behind pupil to change shape and focus the
image in the retina
Vision cont
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Retina- inner surface in the back of the eye which
contain million of receptors
Rods- visual receptor for black and white
Cones- visual receptors for color
Page 95 in the book Fire Truck
Fovea- central part of the retina where cones exist and
images are projected
Optic Nerve- carries visual information to the brain
for interpretation
Vision cont
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Blind Spot- portion of the retina where the
optic nerve exits the eye, and there are no rods
and cones
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Put hand over one eye, place other hand straight
out at arms length and one finger up, move hand
SLOWLY outward, finger will “disappear”
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Page 94 in the book
Vision cont
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Nearsightednesssee nearby
objects more
clearly
Farsightednesssee faraway
objects more
clearly
Color Blindnessinability to
perceive certain
colors such as
red and green
Color blind test
page 96
Vision cont
Vision cont
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Afterimage- image that remains after stimulation of
the retina has ended
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Cones not used fire to bring the visual system back in
balance
Another afterimage activity on page 97
Vision
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Opponent Processing Theory- opposing retinal
processes enable color vision
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Red – Green
Blue – Yellow
Black – White
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Sensation- Hearing
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Audition- sense of hearing
Pitch- how high or low a sound is
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Depends on the frequency- how many times the
wave passes through a point
Timbre- the complexity of a sound
Intensity- how loud a sound is
Decibels- measure of sounds intensity
(loudness)
Hearing
cont
Hearing cont
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Eardrum- piece of skin stretched tightly over the entrance to
the ear
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Cochlea- snail shaped part of the ear filled with liquid and
small hairs
Cilia- hair cells in the cochlea that receive different frequencies
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Like a real drum
Sound waves hit the ear drum and vibrate, causing connected bones
to vibrate
Like strings on a musical instrument
Auditory Nerve- bundle of nerves that carry sound from the
ear to the brain
Sensation- Touch
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Cutaneous Receptors- nerve receptors in the skin
which respond to pressure, temperature, and pain
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3 Sensations of touch:
Pressure
 Temperature
 Pain
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Sensation- Smell
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Olfaction- the sense of smell
Olfactory bulbs- units that receive odor
molecules and communicate their nature to the
brain
Pheromones- odor chemicals that communicate
a message
Smell cont
Olfactory
nerve
Olfactory
bulb
Nasal
passage
Receptor cells in
olfactory membrane
Smell cont
Number
of correct
answers
Women and young adults
have best sense of smell
4
Women
3
Men
2
0
10-19
20-29
30-39
40-49
50-59
60-69
Age Group
70-79
80-89 90-99
Sensation- Taste
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Taste Receptors- chemical receptors on the tongue
that decode molecules of food or drink to identify
them
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4 Sensations of Taste:
Salt
 Sweet
 Sour
 Bitter
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Sensations
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Sensory Interaction- principle that one sense
may influence another
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Ex smell and taste regarding food