Ch. 1-4 Flashcards
1
Q
Nativism
A
our abilities are innate; knowledge comes from the mind
2
Q
Empiricism
A
objectivity; we can make observations; knowledge comes from the outside world and our experiences
3
Q
Plato
A
Nativist; ideas are superior over materials; sensory organs that detect, but we are the ones who make judgments; cannot trust our senses
4
Q
Aristotle
A
Empiricist; senses provide raw material for knowledge; can trust our senses; tabula rasa
5
Q
tabula rasa
A
we are born blank slates and our experiences write on that blank space to form our knowledge
6
Q
Rene Descartes
A
dualist; believed that mind and body are separate entities
7
Q
George Berkeley
A
there are limitations to our perceptions; not that we cannot trust our senses, but that there are limitations; have to trust ideas more
8
Q
Berkeley’s logical deducation
A
we perceive ordinary objects; we perceive only ideas; therefore, ordinary objects are ideas
9
Q
followers of Plato
A
Rene Descartes and George Berkeley
10
Q
followers of Aristotle
A
Thomas Hobbs and John Locke
11
Q
Thomas Hobbs
A
empiricist; without input, there is nothing to generate thought; mental activity is a consequence of sensation and perception
12
Q
John Locke
A
empiricist; there are first sensory impressions; parts = whole
13
Q
method of constant stimuli
A
when an experimenter presents something, a stimulus, and the participant says “Yes, I perceive it” or “No, I don’t perceive it”; many stimuli with different intensities; repeat measures multiple times then average the responses or otherwise describe the pattern of results
14
Q
example of method of constant stimuli
A
hearing test with presenting tones
15
Q
absolute threshold
A
50% chance of perceiving a stimuli
16
Q
method of limits
A
same as method of constant stimuli but done in sequence rather than at random; in increasing or decreasing order
17
Q
method of adjustment
A
same as method of limits except the participant is in control of adjusting the stimulus
18
Q
signal detection theory
A
two distributions overlapping, can be more separated or can be more layered; criterion; quanities the response of an observer to the presentation of a signal in the presence of “noise”
19
Q
hit [p(Y/Y)] in signal detection theory
A
detect a stimulus that is actually there
20
Q
false alarm [p(N/Y)] in signal detection theory
A
detect a stimulus that is not there
21
Q
miss [p(Y/N)] in signal detection theory
A
stimulus is present, but not detected
22
Q
correct rejection [p(N/N)] in signal detection theory
A
stimulus is not present, and is not detected
23
Q
d’ (d-prime)
A
distance between the peaks (means) of the distributions; describes how easy the stimulus is detected when “noise” is present
24
Q
the larger the d’…
A
the more likely a hit
25
receiver operating characteristic (ROC)
graphs the hits, misses, false alarms, and correct rejections
26
cross-modeling matching
comparing sensations; compare a sensation to another experience to get a better understanding of what someone is perceiving; measure someone's experience
27
neuron
dendrites, cell body, nucleus, myelin sheath, axon, axon terminals; impulses go from dendrites to the axon terminals
28
types of neurons
multipolar interneurons, motor neurons, sensory neurons
29
myelin sheath
protects the axon and increases the speed of impulse transmission; a series of Schwann cells; action potential must "jump" from node to node
30
action potential unmyelinated neuron
slower conduction of action potential along an unmyelinated axon (10 m/s)
31
action potential myelinated neuron
rapid, saltatory action potential along myelinated axon (150 m/s)
32
synapse
gap between neurons; transfer neurotransmitters
33
brain lobes
frontal lobe, parietal lobe, occipital lobe, temporal lobe
34
frontal lobe
higher executive functioning, speech, motor cortex, frontal association area
35
parietal lobe
spatial processing, somatosensory cortex, speech, taste, reading, somatosensory association area
36
occipital lobe
vision
37
temporal lobe
memory, smell, hearing, auditory association area
38
corpus callosum
allows communication between the two hemispheres
39
cerebellum
fine motor movements, memory
40
properties of light
light can be absorbed, scattered, reflected, transmitted, or refracted
41
transmitted
passes through
42
refracted
breaks the light apart into different wavelengths; like light hitting a prism
43
primary layers (outer) of the eye
sclera, cornea
44
sclera
provides support and keeps pressure; basically keeps the whole eye together
45
cornea
thin layer of clear fibers with unmyelinated nerve endings; refracts light
46
primary layers (middle) of the eye
choroid, ciliary body, iris, pupil, lens, vitreous chamber
47
choroid
network blood vessels; heavy pigmentation; prevents scattering of light
48
ciliary body
produces aqueous humor, provides nourishment for the cornea, helps maintain the shape of the overall eye
49
iris
pigment that gives people the color of their eyes, contains blood vessels, essentially a muscle
50
pupil
allows light to enter the eye, controlled by the iris, autonomic nervous system process
51
lens
three parts: capsule, epithelial layer, lens; zonules of zinn
52
zonules of zinn
accomodation; ciliary muscle; focuses refracted light
53
vitreous chamber
clear liquid; nonrenewable; helps maintain the shape of the eye
54
primary layers (inner) of the eye
retina, visual optics
55
retina
a light-sensitive membrane in the back of the eye that contains photoreceptors and other cell types that transduce light; sensory transduction --> when a physical stimulus (light) is changed into neuronal energy
56
visual optics
emmetropia, myopia, hyperopia, astigmatism
57
emmetropia
normal vision
58
myopia
nearsightedness
59
hyperopia
farsightedness
60
astigmatism
lens not accommodating correctly
61
duplex retina theory
rods and cones in the retina
62
photoreceptors
rods and cones; the cells that capture light and initiate the act of seeing
63
3 segments of photoreceptors
outer, inner, and synaptic terminal
64
outer segment of photoreceptors
stores pigment, chromophore captures light, rhodopsin
65
rhodopsin
pigment in rods
66
inner segment of photoreceptors
produces pigment
67
retinal eccentricity
the distance between the retinal image and the fovea
68
foveal center
indent in the back of the eye with highest visual acuity
69
layers of the retina
rods and cones, horizontal cells, amacrine cells, bipolar cells, ganglion cells
70
bipolar cells
messenger of information; connected to rods and cones
71
diffuse bipolar cells
hook up to multiple photoreceptors; project to M ganglion cells
72
midget bipolar cells
connect to single cones; send signals to P ganglion cells
73
luminance levels
scotopic, mesopic, photopic
74
scotopic
starlight, cannot see color, only rods activated; nighttime vision
75
mesopic
can see some color; bright full moon at night; cones and rods activated; Purkinje shift --> shifting cones to rods; dusk; long wavelength to short wavelength
76
photopic
rod saturation begins; only cones activated; good color vision; daytime vision
77
ON-center ganglion cell
spot in center activates the cell; spot in surround turns off the cell of receptive field
78
OFF-center ganglion cell
spot in center turns off the cell; spot in surround activates the cell of receptive field
79
types of ganglion cells
parvo cells, magno cells, konio cells
80
visual pathway
optic tract, optic chiasm, lateral geniculate nucleus (LGN), visual cortex
81
properties of LGN
thalamus, receives fibers, output fibers; made up of ganglion cell pathways
82
functions of LGN
relay station; feedback loop --> light intensity, control over retinal outputs
83
primary visual cortex (striate cortex)
V1; simple and complex cells; sends information to V2
84
secondary visual cortex (extrastriate cortex)
V2
85
objective properties of light
radiance, lumen, illuminance, luminance, reflectance, retinal illuminance
86
subjective properties of light --> what is perceived by someone
brightness and lightness
87
lumen
one lumen is one candlelight
88
illuminance
the amount of light falling on a surface
89
luminance
amount of light reflected off of a surface
90
reflectance
percent of light falling on the surface that is reflected
91
retinal illuminance
the amount of light falling on the retina
92
brightness
amount of light from the source or being reflected
93
lightness
percentage of reflected light relative to the total light on the surface
94
visual angle
determined by size --> actual size of stimulus and size on the retina; proportion: object size/distance
95
Fourier analysis
take the whole, visual scene, and break it down into its component parts, sine waves
96
forms of spatial grating
- square-wave grating: hard lines between light and dark; sawtooth waves
- sine wave grating --> not a simple transition between light and dark; sine waves
97
low spatial frequency filters
encode coarse luminance variations in the world (e.g., large objects, overall shape)
98
high spatial frequency filters
respond to the fine spatial structure of the world (e.g., small objects, detail)
99
cycle
one repetition; from dark bar to light bar
100
four different component that can be manipulated in the Gabor Patches to observe neural responses
contrast, spatial frequency, spatial phase, orientation
101
contrast
difference in illumination; object vs. background, dim area vs. light area on object
102
contrast sensitivity function (CSF)
a function describing how the sensitivity to contrast depends on the spatial frequency of the stimulus
103
simple cell
a cortical neuron whose receptive field has clearly defined excitatory and inhibitory regions; edge detector; stripe detector
104
complex cell
a cortical neuron whose receptive field does not have clearly defined excitatory and inhibitory regions; tuned to a particular orientation and spatial frequency and shows an ocular preference
105
hypercolumn
a 1-millimeter block of striate cortex containing two sets of columns, each covering every possible orientation (0-180 degrees), with one set preferring input from the left eye and one set preferring input from the right eye
106
4 factors that hypercolumns are sensitive to
left or right eye, line orientation, line width, color
107
what pathway
ventral pathway that goes to temporal lobe; visual semantics
108
visual semantics
when you look at a desk, you recognize it as a desk
109
where pathway
dorsal pathway; where is it in the environment
110
contours
object edges; quick, sudden changes in light intensity; first order: quick changes, exist in reality, luminance contour
111
illusory contours
color based; created by the brain; does not exist in reality
112
context
refers to the environment the stimuli is in
113
subjective contours
second order or emergent contours: line orientation, texture; perceived edges of surfaces in locations where there is no physical contour in the image
114
structuralism
theory about how the visual system puts together information; Wilhelm Wundt, E. B. Titchener; reduce brain to structures, experiences to basic components
115
Gestalt principles
law of Prägnanz (good figure), law of proximity, law of similarity, law of good continuation, law of symmetry, law of closure, law of common fate
116
law of Prägnanz (good figure)
ordering of information, regular, orderly, symmetric, simplest
117
law of proximity
based on grouping; objects close together = grouped as a set
118
law of similarity
based on comparing objects, then grouping them together; similar objects are grouped together
119
law of good continuation
based on an object's continuum, direction, likelihood of relatability
120
law of closure
based on experience with the world; fill in missing parts
121
law of common fate
based on motion; similar motion = grouping
122
sensation
the ability to detect a stimulus and, perhaps, to turn that detection into a private experience
123
perception
the act of giving meaning to a detected sensation
124
qualia
private conscious experiences of sensation or perception
125
methods for testing sensation and perception
thresholds, scaling (measuring private experience), signal detection theory, sensory neuroscience, neuroimaging, computational methods
126
Gustav Fechner
founder of psychophysics; thought it would be possible to describe the relation between mind and body using mathematics
127
dualism
the idea that the mind has an existence separate from the material world of the body
128
materialism
the idea that the only thing that exists is matter, and that all things, including the mind and consciousness, are the results of interaction between bits of matter
129
panpsychism
the idea that the mind exists as a property of all matter— that is, all matter has consciousness
130
psychophysics
the science of defining quantitative relationships between physical and psychological (subjective) events
131
two-point touch threshold
the minimum distance at which two stimuli are just perceptible as separate
132
just noticeable difference (JND)
the smallest detectable difference between two stimuli, or the minimum change in a stimulus that enables it to be correctly judged as different from a reference stimulus
133
Weber's law
the principle describing the relationship between stimulus and resulting sensation that says the just noticeable difference is a constant fraction of the comparison stimulus
134
Fechner's law
a principle describing the relationship between stimulus and resulting sensation that says the magnitude of subjective sensation increases proportionally to the logarithm of the stimulus intensity
135
absolute threshold
the minimum amount of stimulation necessary for a person to detect a stimulus 50% of the time
136
scaling methods
used to figure out how strong one's experiences are
137
magnitude estimation
a psychophysical method in which the participant assigns values according to perceived magnitudes of the stimuli
138
cross-modality matching
the ability to match the intensities of sensations that come from different sensory modalities; allows insight into sensory differences
139
criterion (signal detection theory)
an internal threshold that is set by the observer; if the internal response is above criterion, the observer detects the stimulus; if the internal response is below criterion, the observer does not detect the stimulus
140
sensitivity (signal detection theory)
a measure that defines the ease with which an observer can tell the difference between the presence and absence of a stimulus or the difference between Stimulus 1 and Stimulus 2; d' (d-prime)
141
receiver operating characteristic (ROC) curve
graphical plot of signal detection theory of the hit rate as a function of the false-alarm rate; if these are the same, points fall on the diagonal, indicating that the observer cannot tell the difference between the presence and absence of the signal; as the observer’s sensitivity increases, the curve bows upward toward the upper left corner; that point represents a perfect ability to distinguish signal from noise
142
excitatory
some neurons increase the response of the next neuron
143
inhibitory
some neurons decrease the response of the next neuron
144
two ways to conceptualize light
as a wave or as a stream of photons
145
wave
an oscillation that travels through a medium by transferring energy from one particle or point to another without causing any permanent displacement of the medium
146
photon
a quantum of visible light or other form of electromagnetic radiation demonstrating both particle and wave properties
147
hue
the perceptual attribute of colors that enables us to classify visible light wavelengths
148
what happens to light on its way from a star to an eye
- some photons are absorbed when they reach the atmosphere
- some of the light is scattered by particles in the atmosphere
- most of the photons make it through the atmosphere and eventually hit the surface of an object
- if it strikes a light-colored surface, most of the light would be reflected
- if it strikes a dark-colored surface, most of the light would be absorbed
- light that is neither absorbed nor reflected is transmitted
- if the light travels through glass, it is refracted
149
scatter
to disperse in an irregular fashion
150
reflect
to redirect something that strikes a surface
151
cornea
transparent outermost layer of the eye
152
aqueous humor
watery fluid in the anterior chamber (space between the cornea and the iris) of the eye
153
vitreous humor
the transparent fluid that fills the vitreous chamber in the posterior part of the eye
154
four optical components of the eye that must be perfectly matched to the length of the eyeball to focus on distant light
cornea, aqueous humor, lens, and vitreous humor
155
accommodation
the process by which the eye changes its focus; lens brings close things into focus with ciliary muscle (iris)
156
presbyopia
the age-related loss of accommodation, which makes it difficult to focus on near objects
157
cataract
an opacity of the crystalline lens
158
emmetropia
the condition in which there is no refractive error because the refractive power of the eye is perfectly matched to the length of the eyeball
159
refractive error
a very common disorder in which the image of the world is not clearly focused on the retina
160
myopia
nearsightedness; a common condition in which light entering the eye is focused in front of the retina, and distant objects cannot be seen sharply; eyeball is too long for the optics
161
hyperopia
farsightedness; a common condition in which light entering the eye is focused behind the retina and accommodation is required in order to see near objects clearly; eyeball is too short for the optics
162
astigmatism
a visual defect caused by the unequal curving of one or more of the refractive surfaces of the eye, usually the cornea
163
fundus
the back layer of the retina
164
optic disc
point where the arteries and veins that feed the retina enter the eye and where axons of ganglion cells leave the eye via the optic nerve; blind spot
165
fovea
a small pit containing the highest concentration of cones and no rods; produces the highest visual acuity
166
optical coherence tomography (OCT)
method to see each layer of the retina in cross section
167
transduction in the retina
rods and cones transduce light into neuronal energy
168
when photoreceptors sense light...
they can stimulate neurons in the intermediate layers, including bipolar cells, horizontal cells, and amacrine cells; these neurons then connect with the frontmost layer of the retina, which is made up of ganglion cells, whose axons pass through the optic nerve to the brain
169
each cone has...
one of three different photopigment that differ in the wavelength at which they absorb light most efficiently
170
four primary ways in which the visual system adjusts to changes in illumination
- pupil size
- photopigment regeneration
- duplex retina
- neural circuitry
171
pupil size
can adjust diameter of pupil to account for different lighting conditions
172
photopigment regeneration
after a photopigment molecule is bleached (used to detect a photon), the molecule must be regenerated before it can be used again to absorb another photon; slow regeneration; helps increase sensitivity range
173
duplex retina for adjustment to changes in illumination
use rods to see when the light is low and cones take over when there is too much light for the rods to function well; light compensation mechanism
174
neural circuity for adjustment to changes in illumination
ganglion cells will encode the pattern of relatively dark areas in the retinal image
175
receptive field
the region on the retina in which visual stimuli influence a neuron's firing rate
176
five major classes of neurons in the retina
photoreceptors, horizontal cells, bipolar cells, amacrine cells, and ganglion cells
177
parts of a photoreceptor
outer segment, inner segment, and synaptic terminal
178
rhodopsin
the visual pigment found in rods
179
visual pigment consists of...
a protein (opsin) and a chromophore
180
chromophore
the light-catching part of the visual pigments of the retina
181
horizontal cell
a specialized retinal cell that contacts both photoreceptor and bipolar cells; run perpendicular to the photoreceptors
182
lateral inhibition
antagonistic neural interaction between adjacent regions of the retina
183
amacrine cells
a retinal cell found in the inner nuclear layer that makes synaptic contacts with bipolar cells, ganglion cells, and other amacrine cells
184
form a vertical pathway in the retina
photoreceptors, bipolar cells, and ganglion cells
185
bipolar cell
a retinal cell that synapses with either rods or cones (not both) and with horizontal cells then passes the signals on to ganglion cells
186
diffuse bipolar cell
a bipolar retinal cell whose processes are spread out to receive input from multiple cones
187
midget bipolar cells
a small bipolar cell in the central retina that receives input from a single cone and pass information on to single ganglion cells
188
ON bipolar cell
a bipolar cell that depolarizes in response to an increase in light captured by the cones
189
OFF bipolar cell
a bipolar cell that hyperpolarizes in response to an increase in light captured by the cones
190
ganglion cell
a retinal cell that receives visual information from photoreceptors via two intermediate neuron types (bipolar and amacrine cells) and transmits information to the brain and midbrain
191
P ganglion cell
a small ganglion cell that receives excitatory input from single midget bipolar cells and feeds the parvocellular layer of the LGN
192
M ganglion cell
a ganglion cell resembling a little umbrella that receives excitatory input from diffuse bipolar cells and feeds the magnocellular layer of the LGN
193
koniocellular cell
a neuron located between the magnocellular and parvocellular layers of the LGN; bistratified ganglion cells
194
amblyopia
a developmental disorder characterized by reduced spatial vision in an otherwise healthy eye, even with proper correction for refractive error
195
minimum visible acuity
refers to the smallest object that one can detect
196
minimum resolvable acuity
refers to the smallest angular separation between neighboring objects that one can resolve
197
minimum recognizable acuity
refers to the angular size of the smallest feature that one can recognize or identify
198
minimum discriminable acuity
refers to the angular size of the smallest change in a feature that one can discriminate
199
contrast sensitivity function (CSF)
a function describing how the sensitivity to contrast depends on the spatial frequency (size) of the stimulus
200
contrast threshold
the smallest amount of contrast required to detect a pattern
201
fourier analysis
a mathematical procedure by which any signal can be separated into component sine waves at different frequencies
202
phase
the position of a grating relative to a fixed position measured in degrees, where one complete cycle is 360 degrees
203
when spatial frequency of the grating is too low...
the ganglion cell responds weakly because part of the fat, bright bar of the grating lands in the inhibitory surround, damping the cell's response
204
when spatial frequency of the grating is too high...
the ganglion cell responds weakly because both dark and bright stripes fall within the receptive-field center, washing out the response
205
lateral geniculate nucleus (LGN)
a structure in the thalamus, part of the midbrain, that receives input from the retinal ganglion cells and has input and output connections to the visual cortex
206
6 layers of the LGN split into 2 types
magnocellular layers and parvocellular layers
207
magnocellular layers
either of the bottom two neuron-containing layers of the LGN, the cells of which are physically larger than those in the top four layers
208
parvocellular layers
any of the top four neuron-containing layers of the LGN, the cells of which are physically smaller than those in the bottom two layers
209
koniocellular cells
a neuron located between the magnocellular and parvocellular layers of the LGN
210
left LGN
receives projections from the left side of the retina in both eyes
211
right LGN
receives projections from the right side of both retinas
212
striate cortex
the area of the cerebral cortex of the brain that receives direct inputs from the LGN as well as feedback from other brain areas; consists of six major layers
213
cortical magnification
the amount of cortical area devoted to a specific region in the visual field
214
consequence of cortical magnification
visual acuity declines in an orderly fashion with eccentricity
215
visual crowding
the deleterious effect of clutter on peripheral object recognition; an essential bottleneck
216
orientation tuning
the tendency of neurons in striate cortex to respond optimally to certain orientations and less to others
217
ocular dominance
the property of the receptive fields of striate cortex neurons by which they demonstrate a preference, responding somewhat more rapidly when a stimulus is presented in one eye than when it is presented in the other
218
each neuron in the striate cortex responds to a distinctive set of stimulus properties
stripes, edges, and/or gratings that are oriented at a particular angle, with a particular width or spatial frequency, possibly moving in a particular direction
219
column
a vertical arrangement of neurons; neurons within a single column tend to have similar receptive fields and similar orientation preferences
220
adaptation
a reduction in response caused by prior or continuing stimulation
221
spatial-frequency channel
a pattern analyzer, implemented by an ensemble of cortical neurons, in which each set of neurons is tuned to a limited range of spatial frequencies
222
extrastriate cortex
the region of cortex bordering the primary visual cortex and containing multiple areas involved in visual processing
223
border ownership
when one object is in front of another there will be a visual border formed between the object and the background; that border is "owned" by the object; it is the edge of the object, not a property of the background
224
what and where pathways
from the extrastriate regions of the occipital lobe, visual information moves out along two main pathways
225
where pathway
heads up (dorsally) into the parietal lobe from the extrastriate regions; process information relating to teh location of objects in space and the actions required to interact with them; plays an important role in the deployment of attention
226
what pathway
heads down (ventrally) into the temporal lobe from the extrastriate regions; appears to be the locus for the explicit acts of object recognition
227
agnosia
a failure to recognize objects in spite of the ability to see them
228
inferotemporal (IT) cortex
part of the cerebral cortex in the lower portion of the temporal lobe, important in object recognition; found to be connected to agnosia
229
homologous regions
brain regions that appear to have the same function in different species
230
fusiform face area (FFA)
a region of extrastriate visual cortex in humans that is specifically and reliably activated by human faces
231
extrastriate body area (EBA)
a region of extrastriate visual cortex in humans that is specifically and reliably activated by images of the body other than the face
232
parahippocampal place area (PPA)
a region of extrastriate visual cortex in humans that is specifically and reliably activated more by images of places than by other stimuli
232
visual word form area (VWFA)
a region of extrastriate visual cortex in humans that is specifically and reliably activated more by images of written words than by other stimuli
233
feedforward process
a process that carries out a computation one neural step after another, without need for feedback from a later stage to an earlier stage
234
reverse-hierarchy theory
a theory that fast, feedforward processes can give you crude information about objects and scenes based on activity in high-level parts of the visual cortex
235
mid-level (middle) vision
a loosely defined stage of visual processing that comes after basic features have been extracted from the image (low-level vision) and before object recognition and scene understanding (high-level vision)
236
goal of mid-level vision
to organize the elements of a visual scene into groups that we can then recognize as objects
237
illusory contour
a contour that is perceived even though nothing changes from one side of it to the other in an image
238
occlusion
one guess the visual system may make that a line suddenly stops is becuase something else gets in the way, hiding it from view
239
structuralism
in reference to perception, a school of thought that believed that complex objects or perception could be understood by analysis of the components
240
Gestalt
in reference to perception, a school of thought stressing that the perceptual whole can be greater than the apparent sum of the parts; perceptual whole is more than the sum of its sensory parts
241
Gestalt grouping rules
a set of rules describing which elements in an image will appear to group together
242
texture segmentation
carving an image into regions of common texture properties
243
parallelism
a rule for figure-ground assignment stating that parallel contours are likely to belong to the same figure
244
symmetry
a rule for figure-ground assignment stating that symmetrical regions are more likely to be seen as figure
245
camouflage
getting your features to group with the features of the environment so as to persuade an observer that your features do not form a perceptual group of their own
246
ambiguity and perceptual "committees"
a host of rules, principles, and good guesses contribute to our organized perception of the world
247
ambiguous figure
a visual stimulus that gives rise to two or more interpretations of its identity
248
necker cube
an outline that is perceptually bi-stable; unlike the situation with most stimuli, two interpretations continually battle for perceptual dominance
249
accidental viewpoint
a viewing position that produces some regularity in the visual image that is not present in the world
250
figure-ground assignment
the process of determining that some regions of an image belong to a foreground object (figure) and other regions are part of the background (ground)
251
principles at work in the assignment of regions to figure or ground
- surroundedness
- size --> the smaller region is likely to be the figure
- symmetry --> a symmetrical region is more likely to be seen as a figure
- parallelism --> regions with parallel contours are more likely to be seen as figures
- relative motion --> how surface details move relative to an edge can also determine which portion of a display is the foreground figure and which is the background
252
dealing with occlusion
- relatability
- heuristic
- nonaccidental features
- Gestalt principle of good continuation
253
relatability
the degree to which two line segments appear to be part of the same contour
254
heuristic
a mental shortcut
255
nonaccidental features
a feature of an object that is not dependent on the exact (or accidental) viewing position of the observer
256
global superiority effect
the finding in various experiments that the properties of the whole object take precedence over the properties of parts of the object
257
summarizing mid-level vision
- early-vision processes give us the local features in the visual world
- mid-level vision processes begin the work of understanding what those local features might be telling us about the state of the world
- bring together that which should be brought together (Gestalt grouping principles)
- use what you know
- avoid accidents
- seek consensus and avoid ambiguity
258
pandemonium model
an account of letter recognition, a relatively simple subset of the object recognition problem; used "demons" as metaphor for processes
259
template
the internal representation of a stimulus that is used to recognize the stimulus in the world
260
structural description
a description of an object in terms of the nature of its constituent parts and the relationships between those parts
261
recognition-by-components model
model of object recognition, which holds that objects are recognized by the identities and relationships of their component parts
262
geons
"geometric ions" out of which perceptual objects are built
263
entry-level category
for an object, the label that comes to mind most quickly when we identify it; at the subordinate level, the object might be more specifically named; at the superordinate level, it might be more generally named
264
holistic processing
processing based on analysis of the entire object or scene and not on adding together a set of smaller parts or features
265
prosopagnosia
an inability to recognize faces; caused by damage to specific areas in the temporal lobe
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congenital prosopagnosia
a form of face blindness apparently present from birth
