Chapter 4 Review
A) Vision
1. Wavelength (Hue)
- Distance between one wave and the
other
- Perception of color
- longer “red”
- Short “blue”
2. Amplitude
- Height of wave
- Perception of brightness
- The taller the brighter
3. Purity
- Mixture of wavelengths that create
color
4. Cornea
- Transparent window of the eye.
- Outer layer
5. Lens
- Changes shape to help focus near or
far objects on the retina
6. Iris
- Colored muscle around the ring that
constricts or dilates w/ light
- Contracts to change size of pupil for
light
7. Pupil
- Amount of light controls size of pupil
by constricting to let in less light
8. Retina
- transduction
- Ambassador to the central nervous
system
- Absorbs light, processes images and
sends information to the brain
9. Optic disk
- Hole in the retina where the optic
nerve fibers exit the eye
- Considered the “blind spot” of the eye
(you cannot see the part of the image
that falls on it)
10. Optic nerve
- Fibers that sends the message to the
brain
11. Rods
- Receptor in eye
- Black and white & low light vision
- 100-125 million
- Generate neural signals that then
activate bipolar cells
12. Cones
- Color and daylight vision
- 5 – 6.4 million
- Generate neural signals that then
activate bipolar cells
13. Light
- Electromagnetic radiation
- Emitted from energy (sun, light bulbs)
14. Nearsightedness
- Can see from near
- Focus falls short of the retina
15. Farsightedness
- Can see from far
- Focus lands past the retina
16. Receptive fields
- Where rods and cones are located
- When stimulated they funnel signals
to a particular visual cell in the retina
17. Lateral antagonism
- Send sideways to other cells
- Occurs when neural activity in a cell
opposes activity in surrounding cells
18. Monocular & binocular cues
- Binocular Disparity: The closer an
object gets to the eyes, the greater the
difference is in the image that is seen
of that object.
- Monocular: one eye binocular: two
eyes.
- Perception of depth is distorted with
one eye and is better measured when
two eyes give cues.
Depth perception involves
interpretation of visual cues that
indicate how near or far away objects
are
Retinal disparity
- Images are sent to slightly different
locations of the right and left eye, so
right and left eyes see different views
- The closer you get to an object, the
greater the disparity b/w images seen
by both eyes
Size constancy
- The ability to perceive things as their
actual size even when your retinal
image gets smaller
Convergence
- Sensing the eyes converging toward
each other as they focus on closer
objects
Vision acuity
- Involved in sharpness and precise
detail in vision
- Greatest in the fovea (which is a tiny
spot in the center of the retina that
only contains cones)
- Cones provide better visual acuity
than rods but rods provide some as
well
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19.
20.
21.
22.
B) Hearing
1. Wavelength
- Pitch
- Measured by cycles per second.
Higher the frequency, the higher the
pitch
2. Amplitude
- Loudness
- Measured with decibel levels
- Higher, louder
3. Purity
- Combination of qualities of a sound
that distinguish it from other sounds
of the same pitch & volume
4. Pinna
- External ear
Collects sound from vibration of air
molecules
5. Hammer, anvil, stirrup
- Middle ear
- Tiniest bones in body
- Vibration of bones creates sound
- Transfer sound from the tympanic
membrane to the oval window
6. Middle ear
- Same as above
7. Cochlea
- Inner ear
- Waves in the fluid stimulate hair cells
- Contains auditory receptors
- Tube like structure
8. Semicircular canals
- Influences balance
9. Auditory pathway
- See all 6 steps in notes
10. Intensity
- loudness
11. Timing
- Shadow heard in each ear
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C) Other senses
1. Gustation
- Sense of taste
- Receptors are taste buds
- Lips have the largest number of
sensory neurons
2. Taste pathway
- Absorb chemicals, trigger neural
impulses and send the info to the
thalamas and on to the cortex
3. Primary tastes
- Sweet, sour, bitter and salty. (5th taste
is umami)
4. Nontasters vs supertasters
- Supertasters are much more sensitive
to certain sweet and bitter tastes. 25%
of people fall into this category. Tend
to more negatively toward alcohol and
smoking which reduces their chances
of developing a drinking problem or
addiction to nicotine. (more likely
women than men)
Nontasters make up 25% of the
population and have have about ¼ the
taste buds as supertasters
- The other 50% of the population are
“medium tasters”
5. Olfaction
- Sense of smell
- Located in the upper portion of the
nasal passage
- Receptors have synapse set up
straight to the base of the brain. (only
sense to skip the thalamus)
- Humans can identify 10,000 odors but
have a hard time attaching names to
odors
6. Pathway of smell
- Olfactory cilia- neural impulseolfactory nerve – olfactory bulb
7. Temperature
- Registered by free nerve endings in
the skin. Receptors specific to hot and
cold temperatures
8. Pain receptors
- Registered in free nerve endings
- Two path ways: fast and slow.
9. Kinesthetic
- Knowing the position of the various
parts of the body
- Receptors lie in the joints and muscles
- Taste is a learned sense and is also
social (you eat things because of your
environment and what is socially
acceptable in your culture)
10. Vestibular
- Keeps you informed of your body’s
location in space
- equilibrium
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D) Perception
1. Reversible figure
- A drawing that is made to have two
interpretations
- Same visual points can result in
radically different perceptions
2. Perceptual sets
A readiness to perceive a stimuli in a
particular way
- Creates a certain bias in someone
- Can change someone’s perception by
altering expectations
Inattentional blindness
- Failure to see visible objects or events
because ones attention is somewhere
else
Top- down processing (aka form
perception theory b/c we process actual
form first then features)
- Assemble visible input into a more
complex form
Bottom-up processing (aka feature
detection theory b/c we process features
first)
- A progression from the individual
elements to the whole
Subjective contours
- Perception of contours where none
actually exist
Gesalt principles:
a. Figure-ground
- figures have more shape and appear
to be closer, stand out in front of
background
b. Proximity
- Things closer together seem to belong
together
c. Similarity
- Group elements of stimuli that are
smaller
d. Continuity
- Group “smooth paths”
e. Closure
- Complete figures that actually have
gaps in them
f. Simplicity
- Group elements in the most simplest
form
Perceptual hypothesis & how context
plays a role
- When you look at something you
develop a perceptual hypothesis
based on prior knowledge
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3.
4.
5.
6.
7.
8.
We use context in which something
appears to guide our hypothesis
9. Perceptual constancy
- tendency to experience a stable
perception in the face of continually
changing sensory input; people tend
to view objects as having a stable size,
shape, brightness, hue, and texture
10. Motion parallax
- Cue to depth that involves images of
objects at different distances moving
across the retina at different rates
- Things that are closer appear to be
moving more or moving faster than
objects further away
11. Pictorial depth cues
- Clues about distance in a flat picture
12. Optical illusions
- Visual appearance seems different
even though physical reality is
actually the same
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13. Motion aftereffect
- After focusing on an image, you
continue to see the image when it is
removed
E) Names
1. Fechner
- Came up with the concept of threshold
2. Weber
- Webers law: size of JND proportional
to size of initial stimuli
3. Hubel & Weisel
- Discovered that visual cortex has
detectors (cortical cells) in it, neurons
that respond selectively to very
specific features of stimuli such as
lines and edges
4. Hermann von Helmholtz
- Place theory
- Proposed that perception of pitch
corresponds to the vibration of
different portion of the basilar
membrane
5. Rutherford
- Frequency theory
- Perception of pitch corresponds to the
rate or frequency at which the entire
basilar membrane vibrates causing
the auditory nerve to fire at different
rates for different frequencies
6. Georg von Bekesy
- Claimed both theories above are valid.
Membrane does move, but the waves
peak at particular places of the
membrane depending on the
frequency.
7. E.G Boring
- Reversible figure
8. Walk & Gibson
- Visual cliff
- Concept of perceiving depth
- When do we identify that something
has depth and is dangerous? This was
what his experiment was about
F) Key terms
1. Sensation
- Stimulation of sensory organs
2. Threshold
- Dividing point b/w energy levels that
do and do not have a detectable effect
- What is the weakest detectable
stimuli?
3. Absolute Threshold
- Minimum stimulus intensity that an
organism can detect.
- Detected 50% of the time
- Created by Gustav Fechner
- Adapts to your environment in order
to sense harm.
4. Transduction
- Converting stimulation of the senses
into neural impulses
5. Just noticeable difference
- Smallest difference detected
- People who can detect smallest
difference are known as experts
6. Signal detection theory
- Study of peoples tendencies to make
correct judgments in detecting the
presence of stimuli
- Responses will depend on your
standard you set for how sure you
must feel before you react
- Decision can be thrown off due to
other factors i.e. Alcohol, fatigue,
drugs
7. Subliminal perception
- Registration of sensory input without
conscious awareness
- Example drive in movie with “eat
popcorn” in background had popcorn
sales raise by 58%
8. Mere-exposure effect
- Develop a positive attitude toward a
product that has been advertised
repeatedly in the media
9. Sensory adaptation
- Decline in sensitivity to prolonged
stimuli
- Adapt in order to identify threats
10. Trichromatic theory
- Three color receptors; red, green and
blue
11. Opponent Process Theory
- Said we need yellow to form all colors
- Three receptors…one receptor is for
red and green, one is for blue and
yellow, and other is black and white
- If one wavelength is being picked up
by receptor the other colors
wavelength is blocked off. Example if
picking up red wavelength, you cannot
pick up green
12. Phi phenomenon(Apparent motion)
- The illusion of motion due to the
flashing of lights in a continuous
pattern.
13. Vestibular sense
- monitors balance in response to
movement detected by the
proprioceptors.
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The vestibular sense receives
information from the semicircular
canals and the vestibular sacs, located
in the ear.
The semicircular canals and vestibular
sacs are filled with fluid and lined with
hair cells that response to movement
and changes in the body.