Exam 3 Flashcards
(188 cards)
1
Q
What are the 3 Functions of Color Vision?
A
Color helps us classify and identify colors.
Color facilitates perceptual organizaton
Color allows us to survive
2
Q
What did Issac Newton propose regarding white light?
A
Isaac Newton proposed that white light was a mixture of differently colored lights.
3
Q
What is a prism?
A
A prism was in an object that could separate the different colors from the white light.
4
Q
What is the visual spectrum?
A
Visual spectrum colors that humans can perceive; 400-700 nanometers
5
Q
How many nanometers can people see color?
A
Humans can perceive about 400-700 nanometers
6
Q
How can you identify a Blue wavelength?
A
Blue- short wavelength
7
Q
How can you Identify green wavelengths?
A
Green-medium(middle) wavelength
8
Q
How can you identify a yellow wavelength?
A
Yellow- medium/long wavelength (a combo of the 2)
9
Q
How can you identify a red wavelength?
A
Red- long wavelength
10
Q
How do wavelengths get processed?
A
The color of an object is determined by wavelengths that are reflected by light into the eyes.
11
Q
What are chromatic colors?
A
When light is able to reflect different wavelengths, think of red, green, blue.
12
Q
What are Achromatic colors?
A
When light reflects EQUAL wavelengths (ex. white, black, and gray)
13
Q
What is selective reflection?
A
When some colors reflect more than others.
14
Q
What is selective transmission?
A
transmission curves are used to plot the percentage of light reflected or transmitted to perceive specific wavelengths.
15
Q
What is the use of the reflectance and transmission curves?
A
They are used to plot the percentage of light reflected or transmitted to perceive specific wavelengths.
16
Q
What two ways can we mix color to describe different wavelengths?
A
Mixing Paints
Mixing Lights
17
Q
What happens when you mix paint colors?
A
Paint absorbs or takes away colors- short, medium, and long wavelengths mixed together creates black
18
Q
What happens when you mix light colors? 💡
A
When light of short, medium, and long wavelengths are superimposed (placed over each other) they reflect a white light.
19
Q
What is subtractive color mixture?
A
Paint is a subtractive color mixture when 2 mixed wavelengths lose their colors.
20
Q
What are the three perceptual dimensions of color?
A
- Hue
- Value
- Pureness
21
Q
What is hue?
A
Hue is the color being assessed
22
Q
What is Value?
A
The perceived brightness of the color
23
Q
What is saturation?
A
The perceived pureness of color
24
Q
What is DeSaturation?
A
The fading of color is due to more white in it.
25
What is the HSV color solid?
HSV= a new way to look at a hue, value, and saturation together.
26
What is the trichromatic theory of color vision?
When 3 different receptor mechanisms are responsible for color vision.
27
How many wavelengths do we rely on?
3 Wavelengths
28
What is the color matching experiment?
Adjust 3 wavelengths in a comparison field to match a test field of one wavelength
29
What is a test field?
The color light the experimenter wants the observer to match.
30
What is a comparison field?
The observer must manipulate the lightning to match the test field color.
31
What are the key findings of the color-matching experiment?
Adjusting 3 wavelengths= possible to match any colors in the test field.
Adjusting 2 wavelengths only= cannot match all colors
Normal color vision = requires 3 receptors
32
The cones consist of 3 pigments – what are they?
1 Short-wavelengths, 2 medium-wavelengths, and 3 long-wavelengths.
33
What is the visual pigment molecule?
retinal bends from ospin to produce light
34
What does the retinal represent?
protein structure differs representing the 3 different pigments
35
What does the opsin represent?
protein structure differs representing the 3 different pigments.
36
What is metamerism?
a situation in which colors of different wavelengths create an identical color.
37
What are metamers?
different wavelengths that come together to make a similar color
38
What happens when you have one receptor?
1 Receptor=1 Pigment
| Wavelengths cannot be identified- color from light looks the same (shades of gray)
39
What is the principle of Principle univariance?
receptors cannot detect differences in wavelengths, only the intensity of light
40
What are the two theories of color vision?
1. ) Trichromatic theory of color vision. Proposed by Helmholtz, Young, and Maxwell
2. ) opponent-process theory. Proposed by Hering
41
What is the trichromatic theory of color vision?
explains cones in the retina
42
What is the opponent-process theory?
explains neural response from cones to the brain.
43
What is the phenomenological method?
describing an observation.
People observed a color circle - people were able to identify changes of a color
Note: The color circle leaves out saturation and value and focuses on the hue only
- this is different from a color (HSV) solid
44
What did Hering observe in the color circle?
Hering showed that differences in colors were observed as primary colors (red, yellow, green, or blue) are added in small amounts
He noticed that certain colors do not mix
45
What colors do not mix – opponent colors?
You can have bluish red and bluish green but not bluish yellow.
This led to the idea that certain pairs of colors are opposites and do not mix.
Color vision consists of opposing responses:
Blue/yellow
Green/red
Black/white
46
Based on physiological evidence of the opponent-process, what are opponent neurons and where are they located?
They respond in an excitatory way to one end of the visible spectrum and an inhibitory way to the other for color pairings.
Excitatory (positive) = neurons fire
Inhibitory (negative) = neurons don't fire
in the retina and Lateral Geniculate Nucleus (LGN)
47
What are primary colors?
Red, yellow, green, or blue.
48
What are complementary after-images?
Seeing the opposite side of the color circle when a color disappears from an image. If green in an image disappears, you see red.
49
What are opponent neurons?
O.N responds in an excitatory manner to one end of the visible spectrum and an inhibitory manner to the other for color pairings.
50
How do the trichromatic and opponent-process theories work together?
Each theory describes physiological mechanisms in the visual system.
Trichromatic theory - explains cones in the retina
Opponent-process theory- explains neural response from cones to the brain.
51
Is there a single color center in the cortex?
There is no single area for color perception.
52
What is cerebral achromatopsia?
Cerebral Achromatopsia- brain damage causing loss of color vision.
53
What is color deficiency?
Partial loss of color perception
dichromats; some colors can still be observed.
54
How is it different from color blindness?
Color Blindness= they can’t see any colors AT ALL, just white, gray, and black; a monochromat.
55
What are unilateral dichromats?
People with trichromatic vision in one eye and dichromatic vision in the other.
56
What are Ishihara plates?
A color vision test to diagnose people with color deficiencies.
57
What is a monochromat?
Rare hereditary condition of color blindness
Only rods and no functioning cones
Perceives white, gray, and black tones
Poor visual acuity (unable to see details)
Sensitive to bright light
58
What colors do monochromats see?
Perceives white, gray, and black tones
59
Describe the problems someone who is a monochromat may deal with in their color vision.
Poor visual acuity (unable to see details)
| Sensitive to bright light
60
What is a dichromat?
Perceives some color but not all; lacks one type of wavelength
Males tend to have it more than females.
Why? MAles lack the extra X chromosome.
If only 1 X has a genetic defect, the color becomes deficient.
61
Who is more likely to be a dichromat – males or females?
Males tend to have it more than females.
| Why? Males lack the extra X chromosome.
62
What is causing an individual to be a dichromat?
If only 1 X has a genetic defect, the color becomes deficient.
63
What are the three types of dichromats?
Protanopia
Deuteranopia
Tritanopia
64
Explain the issues with protanopia.
Person sees:
Short wavelengths as blue
Fades to gray (neutral point) at 492 Nanometers.
Not able to see green as much.
Long-wavelengths as yellow above the neutral point
However, difficulty seeing red ( lacks long-wavelength pigment)
65
Explain the issues with deuteranopia.
Person sees:
Short wavelengths as blue
Fades to gray (neutral point) at 498 nanometers
Difficulty seeing green (lacks medium wavelength pigment)
Long-wavelengths as yellow above neutral point (not able to see red as much)
66
Explain the issues with tritanopia.
```
Lacking Blue Cones
Difficulty seeing blue (lacks
short-wavelength pigment)
Fades to gray (neutral point) at 570 nm
Long-wavelength as red above neutral
point (unable to see yellow)
VERY RARE
```
67
What is color constancy?
We perceive the colors of objects as not changing even under different lighting.
Prolonged exposure to achromatic color leads to receptors in the cones to adapt to that color, making us less sensitive to that color and more sensitive to other colors not exposed as much.
68
What is lightness constancy?
We perceive achromatic colors (white, gray, and black) as remaining relatively constant
69
What does the term, lightness, mean?
Different shades of grey
70
What is depth perception?
Automatic through repeated exposure of cues.
71
What are the three types of cues to signal depth?
Oculomotor
Monocular
Binocular
72
What is an oculomotor cue?
Cues are given based on sensing the position of the eyes through tension in eye muscles. How our eyeballs move around to identify distance!
73
What is a monocular cue?
Depth cues are created from one eye. Consist of 2 types of cues: Pictorial cues and Motion-produced cues.
74
What is a binocular cue?
Cues that depend on two eyes.
75
Define accommodation
Change in the shape of the lens to focus on objects at different distances.
EX. Lens flatten when the object is far away from the eyes.
76
Define convergence
Inward movement of eyes when focusing on nearby objects.
| Converge = Come Together
77
Monocular cues consist of what two types of cues?
Pictorial cues and Motion-produced cues.
78
What are the eight pictorial cues?
1. ) Occlusion
2. ) Relative Height
3. ) Familiar Size
4. ) Relative Size
5. ) Perspective Convergence
6. ) Atmospheric Perspective
7. ) Texture Gradient
8. ) Shadows
79
What is occlusion?
Think Adventure Time!
| When one object hides or partially hides from another object, causing the hidden object to seem farther away
80
What is relative height?
Objects closer to the base of the horizon are seen as more distant; whereas objects away from the base are seen closer.
81
What is familiar size?
Judging distance according to prior knowledge of the sizes of objects (coins)
82
What is relative size?
When objects are of equal size, the one farther away takes up less of your field of view than the closer one.
83
What is perspective convergence?
Parallel lines appear to come together in the distance, showing an increase in distance (Abby Road)
84
What is atmospheric perspective?
Occurs when distant objects appear less sharp (e.g., being very foggy and unclear) than nearer objects
Farther distances tend to give off short wavelengths from light - that is why the sky looks blue.
85
What is texture gradient?
Think of the lilypads picture!
Elements in a scene seem more closely packed when distance increases. A smaller texture appears in the distance.
86
What are Shadows?
A decrease in light intensity due to blockage of light can provide info for location. Shadows can also make objects 3D.
87
What are the two motion-produced cues?
Sources of depth info that come from an observer's movement.
88
What is motion parallax?
Close objects in direction of movement glide rapidly past but objects in the distance appear to move slowly.
When driving in your car things look like they're moving slower than they actually are.
89
What is deletion?
the covering of an object
90
What is accretion?
the uncovering of an object
91
What is stereoscopic depth perception?
Our awareness of depth through input by both eyes
| Each eye has a different viewpoint
92
What is the difference between a two-dimensional and three-dimensional image?
Positioning.
2D - both eyes receive the same info that Images are flat, relying on monocular cues (pictorial cues) for both eyes
3D - both eyes receive different info Images are positioned in different viewpoints to produce a 3D experience
93
What is strabismus?
Someone who is cross-eyed, a misalignment of the eyes.
94
How do people with strabismus perceive images?
People with strabismus rely on monocular cues instead of binocular cues.
95
What is binocular disparity?
Differences in images from the left and right eyes
96
If both eyes have different viewpoints, how do we perceive an image as a single viewpoint with both eyes?
Corresponding retinal points - points on the retina where an image overlap → falls on the fovea.
97
What are the corresponding retinal points?
Objects that appear in the corresponding retinal points overlap into a single image.
98
What is a horopter?
an imaginary sphere that passes through the point of focus. Objects on the horopter fall on the corresponding points on the 2 retinas
99
What are non-corresponding retinal points?
Objects that do not fall on the horopter.
| These points create different images in both eyes
100
What is absolute disparity?
Objects deviate from falling on corresponding retinal points.
101
What is the angle of disparity?
The amount of absolute disparity indicates how far an object is from the horopter.
102
What is relative disparity?
The difference between the absolute disparity of 2 objects.
103
What is crossed-disparity?
When you focus your horopter from FAR AWAY, a close object in front of you creates a crossed disparity (the close object goes between the focused object of the horopter).
104
What is uncrossed disparity?
When you focus your horopter from a close object, your far object creates an uncrossed disparity (the far object goes to the sides of your close object from the horopter).
105
What is stereopsis?
The ability to perceive depth through binocular disparity (differences in viewpoint for both eyes)
In 3D movies, slightly different positions of an image in the left-eye and right-eye are superimposed (placed over each other) on a screen - this creates stereopsis.
106
How does the visual system match (correspond to) images from the two eyes when both eyes are shown different viewpoints in 3D?
Our visual system is able to detect specific features or parts of an object from both eyes together to form a single 3D object.
107
Has the correspondence problem been resolved?
Researchers are still trying to figure this problem out!
108
What are binocular depth cells?
They are specialized neurons that respond to binocular disparity.
109
What is another name for it?
disparity-selective cells
110
Where are these specialized neurons located?
Located in the primary visual cortex, temporal lobe, and parietal lobe.
111
What do these neurons specifically respond to?
Absolute disparity (i.e., when your left and right eyes create different images and not a single image).
112
What is absolute disparity?
When your left and right eyes create different images and not a single image.
113
What perceptions are interrelated to perceive size?
Depth and size
114
Explain what the Holway and Boring experiment is about and what did they find when depth cues (Part 1) and no depth cues (Part 2) are provided?
A luminous test circle was in the right hallway placed from 10 to 120 feet away
A luminous comparison circle was shown in the left hallway at 10 feet away
Goal: To adjust the diameter of the comparison circle (left hallway) to match the test circle (right hallway) Test circles had the same visual angles in the eye.
115
What is the Visual Angle?
The angle of an object relative to the observer's eye.
116
What is size constancy?
X
117
What are visual illusions?
Perception of an object's size will remain relatively the same even when we view the object at different distances.
118
Describe the Müller-Lyer illusion
Misperceiving two lines with equal lengths as different due to the fins connected to the lines.
119
Describe the Ponzo illusion,
Two same-sized objects are placed over different areas of a railroad track in a picture.
Far objects appear larger than the closer object although both are the same size.
Possible explanation- misapplied size-constancy scaling.
120
Describe the Ames room illusion
2 People of equal size appear very different in size in a room.
One appears like a giant over the other
121
Describe the moon illusion
The moon appears larger on the horizon than when it is higher in the sky.
122
Describe misapplied size constancy scaling,
we view 2D as though it is 3D.
123
Describe conflicting cues theory,
Conflicting cues theory- our misperception of line length is caused by conflicting information: the actual length of lines and the overall length of the figure.
124
Describe size-distance scaling,
Size distance scaling:
| Distance is the same for both people but not the size.
125
Describe relative size,
Relative Size:
| One person is taking up more space than the other in the same distance.
126
Describe apparent-distance theory,
Apparent-Distance Theory:
Horizon moon is surrounded by depth cues while the moon higher in the sky has none.
WHEN WE SEE @ GROUND LEVEL
127
Describe angular size-contrast theory.
Angular Size-Contrast Theory:
The moon appears smaller when surrounded by larger objects.
When we see at the Sky level.
128
What is sound?
2 ways of defying sound:
Physical- sound is what a person senses during hearing through pressure changes occurring in the ears.
Perceptual - sound is what the person experiences, perceives, or interprets during the hearing.
129
What happens when you have two receptors?
Ability to identify 2 wavelengths and not just the intensity of light.
130
What happens when you have 3 receptors?
3 Receptors= 3 Pigments
| Ability to identify 3 wavelengths, creating perception of many colors.
131
What are binocular depth cells?
They are specialized neurons that respond to binocular disparity, sometimes called disparity-selective cells.
132
What are sound waves?
the pattern of air pressure moving or vibrating
133
What two patterns occur with these sound waves?
1. ) Condensation
| 2. ) Rarefaction
134
What is condensation?
when sound first comes out, there is an increase of air pressure in the atmosphere (air molecules are pushed together)
135
What is rarefaction?
when air pressure spreads out in the atmosphere, there is a DECREASE in air pressure (air molecules are more apart)
136
How do sound waves travel?
air pressure from air molecules does not just go outward. The air molecules vibrate BACK and FORTH in a certain way at a location and stay about the same place for that location
137
What is a pure tone?
a pattern of pressure changes mathematically described as a sine wave.
138
What is frequency?
the number of cycles within a given time period
139
What unit of measurement is represented for
| frequency?
Hertz (Hz) - 1 Hz = 1 cycle per second
140
What does frequency represent perceptually?
Represents pitch (tone)
141
What happens to the frequency when
| the tone increases?
frequency increases
142
What is amplitude?
difference in pressure between high and low peaks of wave; the size of air pressure
143
What does amplitude represent perceptually?
Unit of Represents loudness
144
What happens when the peak of the sound wave gets higher?
The higher the peaks of the sound wave, the louder the sound.
145
What is loudness?
Our ability to detect sound!
| Measured based on dB (the level or amplitude of sound) Often referred to as dB SPL (decibel sound pressure level)
146
How do we experience loudness – what happens when it is 0 dB or 120 dB
0 dB - can't hear anything
| 120 dB+ = extremely loud (you can actually destroy your ears and feel pain in your ears)
147
What is the audibility curve?
The combination of loudness and pitch can be graphed into an audibility curve to show the threshold (detection) of hearing
148
How many hertz can we hear sound?
We can hear sounds between 20 Hz to 20,000 Hz
149
Between how many hertz
| are humans most sensitive to sound?
Humans are most sensitive between 2,000 and 4,000 Hz
150
What is the auditory response area?
Auditory response area - the area between hearing in the audibility curve and feeling pain.
151
What is pitch?
our ability to perceive high and low tones
Low frequency = sound of a tuba
High frequency = sound of a piccolo
152
What is timbre?
(pronounced TAM-ber) - our ability to detect differences of sound not due to loudness, pitch, or duration.
EX. - being able to identify different instruments playing at the same loudness, pitch, and duration.
153
What is an attack of sound?
buildup of sound at the beginning of tone
154
What is a decay of sound?
decrease of sound at the end of tone
155
What happens if you eliminate hearing the attack and decay of instruments?
you can have difficulty distinguishing one instrument from another.
156
What are the three basic tasks of the auditory system?
1. ) Sound stimulus enters ear to auditory receptors
2. ) Stimulus from air pressure changes into electrical signals from receptors to the brain (transduction)
3. ) Brain interprets electrical signals (e.g., loudness, pitch, timbre, location)
157
What are the three divisions of the ear?
Outer Ear, Middle Ear, Inner Ear
158
In the outer ear, what are the pinnae?
the physical structure that sticks out of our head (we call them our ears)
159
What is the pinnae’s function?
Helps identify location of sound
160
What is the auditory canal?
Tube-like 3 centimeter long structure
161
What is the canal’s two functions?
Protects the tympanic membrane (a.k.a., eardrum; the part responsible for sound vibration)
Resonance - amplifies (increases) the sounds' frequency between 1,000 and 5,000 Hertz (Hz)
162
What is the tympanic membrane or eardrum,
part responsible for sound vibration)
163
What is resonance?
amplifies (increases) the sounds' frequency between 1,000 and 5,000 Hertz (Hz)
164
In the middle ear, how many cubic centimeters is the cavity (opening)?
2 cubic centimeter cavity (opening) separating inner from the outer ear
165
What are ossicles and how many are there?
3 and they are the smallest bones in body.
166
What are the following:
malleus (hammer)
incus (anvil)
stapes (stirrup)
1.) malleus (hammer)
attached to tympanic membrane; moves due to sound vibration
2.) incus (anvil)
sends a vibration to stapes
3.) stapes (stirrup) -
sends a vibration to the inner ear via the oval window of the cochlea
167
What are the functions of the ossicles?
Air pressure changes are transmitted poorly in the inner ear due to being filled with fluid
Ossicles amplify the air pressure changes (vibrations) when sent to the fluid of the inner ear
Attached to ossicles are middle-ear muscles that help us to perceive sound from the environment without the sound of our voices or chewing interfering what we hear
168
What are the middle-ear muscles?
middle-ear muscles help us to perceive sound from the environment without the sound of our voices or chewing interfering with what we hear.
169
Which division of the ear has fluid? I
INNER EAR
170
In the inner ear, what is the cochlea?
Cochlea: fluid-filled snail-like structure (35 millimeters long if uncoiled) set into vibration by the stapes.
171
When the cochlea is uncoiled, what and where is the cochlear partition, scala vestibule, and scala tympani?
Scala vestibule - upper half of cochlea
| Scala tympani - lower half of cochlea
172
Where is the base and where is the apex?
```
Base = (stapes end)
Apex = (far end)
```
173
What is inside the cochlear partition?
the structures for transforming the vibrations from the cochlea to electrical signals
174
What organ is inside of the
| cochlear partition?
Organ of Corti
175
What are cilia?
hair cells - receptors for hearing)
176
In the organ of Corti, what are the two membranes that help to create electrical signals into the brain?
Basilar membrane - moves up and down when fluid vibration occurs
Tectorial membrane - slides back and forth, moving the hair cells
177
What are the two types of cilia?
Inner hair cells - not in contact with the tectorial membrane but can identify pressure waves from it
Outer hair cells - in contact with the tectorial membrane
178
Who was Georg von Békésy - what did he find?
found that the basilar membrane vibrated like a traveling wave (a motion similar to a rope when you snap it that goes up and down)
179
What is the traveling wave?
(a motion similar to a rope when you snap it that goes up and down)
180
What is the place theory of hearing?
Each place on the basilar membrane is tuned to respond best to a different frequency
181
What is the tonotopic map?
an orderly map of frequencies along its length of the cochlea
182
What area responds best to low frequencies and
| what area responds best to high frequencies?
Apex - responds best to low frequencies
| Base - responds best to high frequencies
183
After the hair cell fire from the cochlea, where do the signals go?
The Brain
Sends info in the following sequence (order):
1.) Cochlear nucleus (brain stem)
2.) Superior olivary nucleus (brain stem)
3.) Inferior colliculus (midbrain)
4.) Medial geniculate nucleus (thalamus)
5.) Auditory receiving area (A1 in temporal lobe)
184
Know the sequence of the
auditory pathway.
CSI Massachusetts:
```
CSI Massachusetts:
Cochlear Nucleus
Superior Olivary Nucleus
Inferior Colliculus
Medial Geniculate Nucleus of the Thalamus
A1-Auditory receiving area
```
185
What is presbycusis?
Presbycusis- loss of sensitivity to hearing high frequencies due to damaging noises or drugs (in addition to aging)
186
What is noise-induced hearing loss?
Noise-Induced Hearing Loss- loud noise for a long period of time can severely damage the organ of Corti
187
What are cochlear implants?
An electrode device that acts as a cochlea and stimulates the auditory nerve fibers.
188
How do hair cells create electrical signals into the auditory nerve fibers?
Vibration (pressure waves) bends hair cells
Bending of hair cells in one direction creates electrical signals (transduction) and bending in opposite direction stops electrical signals
Electrical signals go into the auditory nerve fibers (located in the basilar membrane), where neurons fire into the brain
