Chapter 4 Flashcards
(78 cards)
1
Q
What is the difference between sensation and perception? examples
A
Sensation is the stimulation of sensory organs (light to eye)
Perception is organizing sensory info into representation of physical stimulus
-qualitative experience
(light of different wavelengths into colour)
2
Q
Term for translation and the process that link the two
A
Transduction, the process that links sensation and perception.
- transformation of a physical stimulus into a neural signal
3
Q
How many senses do we have
A
More than the 5 standard senses.
- balance, body position, temperature
4
Q
What is sensory adaptation
A
-gradual decline in sensitivity to a stimulus over prolonged stimulation
(jumping in a cold lake)
- result of sensory neurons firing less and less
cant redirect stimulus to feel cold again
5
Q
What is habituation
A
- decreased response to a repeated stimulus
(clock ticking in the background) - result of simple learning processes in the CNS (not sensory neurons)
can redirect the stimulus if focused on it
6
Q
Visual adaptation
A
- all senses adapt to help us concentrate on what is important. we do not notice this in our eyes because they are constantly moving
- tiny involuntary movements in our eyes ensure that the millions of individual receptors in our eyes are always seeing something new or different
7
Q
Cornea function
A
- protective bump at the front of the eye
- sharply refracts light
- part of focusing light onto retina
- 80% of focusing power but fixed in place
8
Q
Pupil function
A
- hole that allows for light into the eye
- dilation or constriction controlled by muscles in the iris
9
Q
Pupillary reflex does what
A
keep the light entering into the eye at optimal level
10
Q
Iris function
A
dilates or constricts to allow light into the eye
11
Q
Lens function
A
- elastic, crystalline structure that also helps focus light into the retina
- 20% of focus power
- purpose is to focus light precisely onto the retina
- changes shape to accommodate
12
Q
Shapes of the lens and what muscle controls the shape
A
thinner lens is to focus distant objects (bends light less)
thicker lens is to focus closer objects (bends light more)
shape is controlled by the ciliary muscles
13
Q
Function of accomodation
A
the most important function of focussing light onto the retina
14
Q
What is the near point of vision and occurs when?
A
The point at which the image of a close object becomes blurred, occurs when the lens reaches its maximum curvature.
15
Q
Correct terms for nearsighted and farsighted
A
- myopia is nearsightedness
- light is focused in front of the retina, elongation of the eye
- hyperopia is farsightedness
- light is focused behind the retina, shortened eye
16
Q
What is the order of the cells in the retina from the back of the eye
A
- photoreceptors
- horizontal cells
- bipolar cells
- amacrine cells
- ganglion cells
17
Q
Do we have more rods or more cones
A
More rods 120 million per eye
cones 6 million per eye
18
Q
Are cones or rods more sensitive to light what causes it?
A
Rods are extremely sensitive to light
- convergence causes more sensitivity, but poor acuity
19
Q
Which photoreceptor sees in colour
A
Cones see in colour
- 3 different types, special for different wavelengths
20
Q
Which photoreceptor is associated with greater acuity and why?
A
Cones have better acuity because they have no convergence, poorer sensitivity
21
Q
Which photoreceptors are found in the fovea
A
only cones
22
Q
Fovea function 6
A
small area on centre of the retina
- vast majority of vision is here
- involved in directed looking
- highest density of photoreceptors
- great visual acuity
- ONLY CONES each connecting to one bipolar then 1 ganglion cell
23
Q
Which photoreceptors are in peripheral vision
A
mostly rods
24
Q
Which photoreceptors has faster pigment recovery?
A
cones (10 min)
25
What are photo pigments
- proteins that change shape when they absorb light
| - changing shape requires action potential
26
Define dark adaptation
progressive increase in sensitivity to light
27
Why is there a "blip" in sensitivity to light as we adapt to the dark
- as you enter a dark room a fair number of photo-pigments are used up, the likelihood of a photon hitting a ready photo-pigment is not 100%, not very sensitive to dim light
- after awhile, more and more photo-pigments have regenerated, and more means more sensitive
28
What is determined by the frequency of wavelengths?
colour
29
what is determined by amplitude of wavelengths?
brightness
30
What colour most visible in the dark?
yellow
31
What are the three colours of light our cones are sensitive to?
blue green red
32
3 basic types to recognizing or perceiving an object bottom-up theory
Optic nerve to thalamus to primary visual cortex
| - topographic organization
33
What are feature detector cells
in the visual cortex, ganglion cells are combined to feature detector cells
- based off patterns of ganglions firing
- each with own map
34
What are different types of feature detector cells
angle, feature detectors would look at them firing in a horizontal line, vertical line
colour, brightness, movement, distance, shape, texture
35
What is parallel processing?
3 different feature detectors are processed parallel, all of the information is processed at the same time, in different portions of the brain
36
Biedman's Recognition by Components model
- 36 fundamental geons which make up all real-world objects
37
What are geons
- 3D volumetric shapes that make up all real-world objects
38
What is the Principal of Componential Recovery?
- as long as we can perceive the relative size/placement of a few of the geons of an object, we can recognize it
39
3 basic steps to recognizing an object for top-down theory?
1. formulate perceptual hypothesis
2. examine features to check hypothesis
3. recognize stimulus
40
3 things that can influence top-down models
1. organization
2. context
3. attention
41
What are the 7 gestault laws of perceptual perception in a top-down theory
1. law of continuity
2. law of similarity
3. law of proximity
4. law of closure
5. law of figure vs. ground
6. law of meaningfulness or familiarity
7. principal of pragnanz
42
Law of continuity
- points that when linked together would make a straight or smoothly continuous line
43
Law of similarity
-similar things tend to be grouped together
44
Law of proximity
- elements that are near one another tend to be perceived as going together
45
Law of closure
-tend to close edges or fill in gaps to complete an object
46
Law of principal vs. ground
- tend to perceive figure in the foreground, on top of a continuous background
47
Law of meaningfulness or familiarity
- tend to perceive things in terms of meaningful groupings
48
Principal of Pragnanz
- tend to perceive things such that the resulting structure is as simple as possible
- also called law of simplicity
49
Can context mess with perception
- we tend to compare things we actually see with our mental library of schemata, as long as something is close enough, we tend to recognize it
50
Describe Paimers bread box/mailbox study
Asked participants to name line drawn objects, before naming person shown a picture of a scene, and the naming of the object would often be suited for the scene, the mailbox being mistaken for bread because participant was shown a kitchen
51
What is perceptual schema
A perceptual set is a readiness to perceive things a certain way, a perceptual set primes a perceptual schema (mental representations of an object)
52
Describe Harold Kelly's example
Harold Kelly held a guest lecture and gave half of his lecture hall a warm brochure and half a bad one, the reviews reflected exactly what they were given at the beginning because they had a perceptual schema
53
What are perceptual constancies?
the tendency to experience the same, stable perception despite changes in sensory input
-otherwise we would have to re-discover what something is, with changes in lighting or distance
54
What are examples of perceptual constancies?
- size constancy
- lightness constancy
- colour constancy
- melodic constancy
55
Describe size constancy
- size perception is not determined solely by the size of the image on the retina
- size is perceived as constant, even across different distances
- despite that farther objects stimulate less space on the retina
56
Describe shape constancy
- shape perception is not determined solely by the patters on receptor firing
- the shape of an object is perceived as constant, even across different viewpoints
- despite the fact that the 2D shape of retinal stimulation changes
57
Describe brightness constancy
- perception of brightness is not determined solely by the amount of light reflected from it surface
- the lightness of an object is generally perceived as constant, even across different lighting conditions
- despite the fact that different amounts of lights will be reflected, under different lighting conditions
58
Describe colour constancy
- object colour is not determined solely by the wavelength of light reflected from its surface
- the colour of an object is generally perceived as constant, even across different lighting conditions
- despite the fact that different colours of light will affect the wavelength of light that are reflected back
59
What is in-attentional blindness? example
failure to register unattended stimuli in consciousness
- gorilla video
- factors will grab your attention intensity, movement, contrast
60
What sorts of stimuli are better at grabbing attention?
intensity, movement, contrast, personal interests (hunger), sexual, novelty
61
Difference between monocular and binocular depth cues?
Monocular depth cues require only one eye
| Binocular depth cues require both eyes
62
What are the 8 monocular depth cues
```
Linear perspective
Texture/clarity
clarity
interposition
Height in horizontal plane
relative size
light and shadow
motion parallax
```
63
Describe linear perspective
- parallel lines converge into the distance (a vanishing point)
ex. a hallway
64
Describe texture/clarity
- texture appears diner in the distance
| - nearby objects are typically more clearly seen
65
Describe clarity
- distant objects are less clear (or hazy)
66
Describe interposition
-objects in front cut off parts of objects behind
67
Describe height in horizontal plane
-near objects tend to be lower on the horizontal place (farther from the horizon)
68
Describe relative size
-farther objects take up less space on the retina than equally sized objects that are near to us
69
Describe light and shadow
-gives us a sense of 3D shape, depth
70
Describe motion parallax
-as we move objects seem to zip past while fat away ones seem to slowly move with us
71
What are the two binocular depth cues
- binocular disparity
| - convergence
72
Describe binocular disparity
each eye sees a slightly different image of the world
- closer objects=more of a difference
- 3D movies, viewmaster slides use this to produce 3D images
73
Describe convergence
to focus on an object, the eyes both point toward it
| -closer objects your eyes have to turn more inward
74
What are the cues we use for motion perception
motion across retina
motion relative to background
75
Describe the primary cue
motion across the retina
| -cells fire frequently, feature detectors interpret this as motion (the lights going across the top of movie theatres)
76
Describe motion relative to background
can fixate on an object and still "see" it moving despite no change in retinal position
-watching a baseball fly across the stadium
77
Example of how culture affects the way we perceive things
- interpret things based on cultural experiences
- blue basket or window
- muller-lyer illusion
78
How exposure to culture art techniques affects picture interpretation
-not all monocular (pictorial) cues are common across all cultures
