Psych Ch. 4

Psychology- Chapter 4
Perception test
Sensation and Perception
 Simulation
of sensory receptors and
transmission of sensory information to the
central nervous system
 Interpret sensory stimulation
 *Perception is our reaction to sensation
Absolute threshold Weakest
amount of stimulus that can be
Difference thresholds
 minimum
amount of difference between two
Signal detection theory
 distinguishing
sensory stimuli by strengths
and also physical setting, mood, attitudes
Sensory adaptation
More sensitive to weak stimuli and less
sensitive to unchanging stimuli
 Optical
Walking into a dark theatre your eyes will
 Hear a train every day you will not notice it
very much
Light- electromagnetic energy
 Wavelengths
 Roy G. Biv
 Colors
of rainbow- red, orange, yellow, green,
blue, indigo, violet
Ultraviolet and Infrared
The Eye
Pupil- (Black circle) lets in light and is sensitive
to emotions
 Lens- (Blue oval) focuses image on retina
 Cornea- (Outer blue) protection
 Iris- (Dark blue lines) muscle that controls pupil
 Optic nerve- (Back pink) takes image to brain
 Retina- (Back pink) picks up image and relays
to brain
More parts to the eye
 Blind spot- everyone has one in each eye
 Rods (shades) and cones (colors)- 100
million rods, 5 million cones
 Brain fixes images for us even if we don’t
really see that
Visual acuity
20/20 vision
20/20 vision is a term used to express normal
visual acuity (the clarity or sharpness of vision)
measured at a distance of 20 feet. If you have
20/20 vision, you can see clearly at 20 feet what
should normally be seen at that distance. If you
have 20/100 vision, it means that you must be as
close as 20 feet to see what a person with normal
vision can see at 100 feet.
20/20 vision does not mean perfect vision. It only
indicates the sharpness or clarity of vision at a
distance. There are other important vision skills,
among them peripheral awareness or side vision,
eye coordination, depth perception, focusing ability
and color vision that contribute to one's overall
vision ability.
Color vision
Complementary colors
 Afterimage
 Color blindness
Seeing Facts
Most people blink every 2-10 seconds.
Each time you blink, you shut your eyes for 0.3 seconds,
which means your eyes are closed at least 30 minutes a day
just from blinking.
If you only had one eye, everything would appear twodimensional. (This does not work just by closing one eye.)
Owls can see a mouse moving over 150 feet away with light
no brighter than a candle.
The reason cat's and dog's eyes glow at night is because of
silver mirrors in the back of their eyes called the tapetum. This
makes it easier for them to see at night.
An ostrich has eyes that are two inches across. Each eye
weighs more than the brain.
A chameleon's eyes can look in opposite directions at the
same time.
A newborn baby sees the world upside down because it takes
some time for the baby's brain to learn to turn the picture
right-side up. One in every twelve males is color blind.
Pitch- frequency of sound waves
 Loudness- amplitude of sound waves
 Timbre- a distinctive sound
The ear
 Hammer
 Anvil
 Stirrup
 Eardrum
 Ear canal
 Eustachian tube
 Auditory nerve
Conductive deafness- middle ear, deals with
the bones; cure- hearing aids
 Sensorineural deafness- inner ear, no cure
 Stimulation deafness
Hearing Facts
When you go up to high elevations, the change in
pressure causes your ears to pop.
Children have more sensitive ears than adults. They can
recognize a wider variety of noises. Mosquito ringtone
Dolphins have the best sense of hearing among animals.
They are able to hear 14 times better than humans.
Animals hear more sounds than humans.
An earache is caused by too much fluid putting pressure
on your eardrum. Earaches are often the result of an
infection, allergies or a virus.
Olfactory nerve
Taste and smell video
Take a deep breath. Air is sucked up into
your nostrils over bony ridges called
turbinates, which add more surface area to
your sniffer. The air travels over millions of
olfactory receptor neurons that sit on a
stamp-size sheet, the olfactory epithelium,
on the roof of the nasal cavity. Odor
molecules in the air stimulate and inhibit
the receptors.
Each aroma sets off a signal made by the
receptors that travels along the olfactory
nerve to the olfactory bulb. The olfactory
bulb sits underneath the front of your
brain. Signals from the bulb tell your brain
what reeks.
Humans can recognize 10,000 different
odors. However, no two people sense
anything the same.
Smelly Facts
Dogs have 1 million smell cells per nostril and their smell
cells are 100 times larger than humans!
Humans use insect warning chemicals, called
pheromones, to keep away pesky insects!
People who cannot smell have a condition called
If your nose is at its best, you can tell the difference
between 4000-10,000 smells!
As you get older, your sense of smell gets worse.
Children are more likely to have better senses of smell
than their parents or grandparents.
Taste buds
 Bitter
 Sweet
 Sour
 Salty
We have almost 10,000 taste
buds inside our mouths; even
on the roofs of our mouths.
Insects have the most highly
developed sense of taste.
They have taste organs on
their feet, antennae, and
Fish can taste with their fins
and tail as well as their mouth.
In general, girls have more
taste buds than boys.
Taste is the weakest of the
five senses
Skin senses
 Temperature
 Pain
Body Senses
Vestibular sense
 Kinesthesis
 Arms
through the floor
 Arms raise above the head
 Touch your finger- hands wrapped.
The Pinocchio experiment with
body image
* Find 2 willing (and good) friends
* Sit on a chair blind-folded, and ask your friend (let’s call her
Sam) to sit on a chair in front of you, with her back to you.
* Ask your other friend to take your right hand and put it on
Sam’s nose
* Tap and stroke her nose in a gentle random manner,
making exactly identical movements with your other hand, on
your own nose.
* Continue this for 60 seconds
About 50% of people will have the extremely odd sensation that
their nose is 3 feet long, or somehow their nose is elsewhere!
_NM90 freaky body illusions
QJwow broom through body
vestibular sense
The vestibular sense is also connected to parts of the
brain that tell you when it is time to vomit. This is the
cause of motion sickness.
If you spin hard enough and then suddenly stop, the tiny
current keeps going for a little bit, and gives you the
sensation that you are still spinning, but in the opposite
direction. Your brain may try to compensate for this, and
cause you to fall or at very least feel dizzy.
You can also confuse these canals when you take a
shower and allow hot or cold water into your ear. The
temperature changes can cause currents to develop that
wind up feeling just like spinning, and you may get dizzy.
cnU6Hk 10 in 2 minutes
when gaps
are present
Figure ground perception
What we see as
background and what
we perceive as figure
influence our
Power point or word
Place optical illusions in a power point
 Things that express consistancy,
perspective, continuity, similarity, contrast,
figure ground, ect…… no limit. But there
will be expectations of high quality…..
Things that are near each other influence
each other
wPmjmw Proximity and elation
Group objects that
are similar to each
We like to see a
smooth continuous
pattern rather than
individual parts
Common fate
See things moving together you perceive
them as belonging to each other
Perception of movement
Stroboscopic motion
Depth perception
Monocular cues
 Perspective
 Clearness
 Overlapping
 Shadow
 Texture
Binocular cues
Retinal disparity- floating finger
Perceptual constancy’s
 Color
 Brightness
 Shape
 Speed
Visual illusions