Chapter 4 Senses Flashcards
(116 cards)
1
Q
sensation is defined as
A
the stimulation of the senses
2
Q
perception is defined as
A
the selection, organization and interpretation of sensory input (the brain’s way of making sense of it)
3
Q
psychophysics is
A
the study of how physical stimuli are translated into psychological experience (Gustav Fechner)
4
Q
threshold is
A
a dividing point between energy levels that do and do not have a detectable effect
5
Q
absolute threshold
A
for a specific type of sensory input is the minimum amount of stimulation that an organism can detect
- it’s not absolute, though, it’s more of a gradual thing where as the stimulus increases, there’s a stronger likelihood that the person will detect it
- if that detection is at a 50% of the time, then that is considered the absolute threshold
6
Q
just noticeable difference is
A
the smallest difference in the amount of stimulation that a specific sense can detect
7
Q
weber’s law states that
A
the size of a just noticeable difference is a constant proportion of the size of the initial stimulus
eg: for weight, the JND is 1/30
you can tell the difference between something that is 300 grams and 310 grams because 1/30th of 300 is 10
but if you lifted something that was 900 grams, you’d have to lift something that was 930 grams to notice the difference
“webs” are mathematical
8
Q
Fechner’s law states that
A
the magnitude of a sensory experience is proportional to the number of JNDs that the stimulus causing the experience is above the absolute threshold
eg: pitch black and you turn on a light
you notice the light to a strong magnitude
then you turn on another light and don’t really sense the change that much – it’s proportional
in the domain of sensory experience virtually everything is relative
“feching new experiences”
9
Q
signal-detection theory proposes
A
that the detection of stimuli involves decision process as well as sensory processes which are both influenced by a variety of factors besides stimulus intensity
10
Q
define hit, miss, false alarm, correct rejection
A
hit: detecting signals when they are present
miss: failing to detect signals when they are present
false alarm: detecting signals when they are not present
correct rejection: not detecting signals when they are not present
11
Q
subliminal perception
A
the registration of sensory input without conscious awareness
12
Q
sensory adaptation/habituation is
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a gradual decline in sensitivity due to prolonged stimulation
13
Q
what are the 3 properties of light
A
amplitude, wavelength, purity
14
Q
amplitude
A
affects perception of brightness
15
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wavelength
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affects hue
16
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purity
A
affects saturation
greater the purity, the greater the saturation (less mixes of wavelengths)
17
Q
describe the path of vision
A
cornea –> pupil (opens and closer from iris control) –> lens (bends or flattens for focus) –> projects upside down image on the retina –> receptors, cones, rods –> send signals to neurons –> out the optic nerve
18
Q
define lens
A
is the transparent eye structure that focuses the light rays falling on the retina (behind the pupil)
19
Q
define accomodation
A
focussing
when you focus on a close object the lens gets rounder to give you a clear image
when you focus on distant objects the lens flattens
20
Q
define nearsightedness
A
close objects are seen clearly but distant ones are blurry
happens when the lens or cornea bends light too much
the image is focussing too NEAR so the eye ball is TOO LONG
21
Q
define farsightedness
A
far objects seen clearly and near ones blurry
happens when the eyeball is too short
so the image is being focused after the retina - too FAR!!! BEHIND!!
22
Q
define the pupil
A
is the opening in the center of the iris (color part) that helps regulate the amount of light passing into the rear chamber of the eye
when pupil constricts = less light but sharper image
when pupil dilates = more light but blurrier
23
Q
define the retina
A
is the neural tissue lining the inside back surface of the eye; it absorbs light, processes images and sends visual information to the brain
it’s a pice of the central nervous system that happens to be in the eyeball
the spinal cord is a complicated extension of the brain, and the retina is the brain’s envoy in the eye
24
Q
define optic disk
A
is a hole in the retina where the nerve fibers exit the eye
since it’s a hole in the retina, you can’t see the part of the image that falls on it
that said, each eye compensates for the blind spot of the other
25
define receptor site
very sensitive to light are located in the innermost layer of the retina, so light needs to pass through several layers of cells to get to receptors that detect it
26
what are saccades
micro movements that are happening constantly to adjust and scan the environment
27
define cones
are specialized visual receptors that play a key role in daylight vision and color vision
do not respond well to dim light
better visual acuity than rods
concentrated heavily in the centre of the retina and fall off in density toward the periphery
stubbier than rods
28
the fovea is
a tiny spot in the centre of the retina that contains only cones and visual acuity is the sharpest there
29
Rods are
receptors that play a key role in night vision and peripheral vision
longer in shape
peripheral vision because they outnumber the cones on the periphery of the retina by more than 10 to 1
30
dark adaptation is
he process in which the eyes become more sensitive to light in low illumination (going into a movie theatre)
cones adapt more quickly so in the first ten minutes they adapt to handle dimmer light but they it get too dark for them so they stop adapting after 10 minutes
whereas rods are slower, but they keep adapting for a full 30 minutes as they can get really good at seeing in the dark
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light adaptation is
the process in which the eyes become less sensitive to light in high illumination (coming out of the theatre)
32
Describe the processing of visual information within the retina
light strikes cones/rods triggers neural signals that moves from receptors to bipolar cells to ganglion cells, which in turn send signals to the optic nerve a collection of axons that connect the eye with the brain
33
the concepts of receptive fields and lateral antagonism
the receptive field of a visual cell is the retinal area that when stimulated affects the firing of that cell
when receptive fields are stimulated, retinal cells send signals both toward the brain and laterally (sideways) towards nearby cells, allowing an interaction between cells
34
Lateral antagonism (or inhibition) occurs when
neural activity in a cell opposes activity in a surrounding cell
this accounts for contrast, which is really important when recognizing stuff in the outside world to be
35
Describe the routing from eye to brain
axons depart from the eye through the optic disc –> stream of neural impulses to the brain –> optic chiasm –> main pathway (via the lateral geniculate nucleus (side of the thalamus) and then into the occipital lobe OR –> the second pathway superior colliculus (midbrain) then the thalamus then the occipital lobe
coordinates visual stimulus with other sensory input
36
define optic chiasm
the point at which the optic nerves from the inside half of the eye cross over and then project to the opposite half of the brain
37
which side of the brain are optic signals from the retina processed on?
axons from the left half of each retina go to the left half of the brain and axons from the right side of each retina go to the right side of the brain
38
define feature detectors
neurons that respond selectively to more complex stimuli
according to some theorists it goes from pattern of stimulation on the retina to feature detectors to higher level analyzers then to decision making
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feature detectors: what do simple cells process
bars of a particular orientation
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feature detectors: what do complex cells process
movement of correctly oriented bars across the receptive field
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feature detectors: what do hypercomplex cells process
corners, angles, or bars of a particular length moving in a particular direction
42
define subjective contours
perception of contours where there really are none - you fill in the blanks of missing pieces of the circle
and example of top down theory of visual perception
43
what is the routing post visual cortex?
routed through 2 streams to other other cortical areas for further processing
- ventral (the ventre - underside - temporal) stream processes details of 'what' objects are out there and
- dorsal stream (think dorsal fin, middle of brain) which processes 'where' the objects are
44
define visual agnosia
an inability to recognize objects
45
define prosopagnosia
an inability to recognize familiar faces, including one's own face
46
define subtractive color mixing
works by removing some wavelengths of light, leaving less light than was originally there
yellow and blue makes green in paint because pigments absorb most wavelengths, selectively reflecting specific wavelengths that give specific colors
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define additive color mixing
works by superimposing lights, putting more light in the mixture than exists in any one light by itself
shine red, green and blue spotlight on a white surface, you'll have an eg of additive CM
48
trichromatic theory of color vision holds that
the human eye has three types of receptors sensitive to the specific wavelengths associated with red, green and blue (miles david blue in green + red)
TV sets and computer screens use this principle and blend the 3 primary colors
but people have a hard time using these three to describe yellow, so when we give people yellow too, they can then describe any color
research has shown that there are 3 types of cones, with each one being sensitive to different bands of wavelengths
short, medium and long wave lengths that correspond to the trichromatic theory
49
the opponent process theory of color vision holds that
color perception depends on receptors that make antagonistic responses to the three pairs of colors
three pairs of opponent colors are blue/yellow (lakers), red/green (christmas), black/white (michael jackson)
this theory provides substantiation for the afterimage complimentary effect and the need for yellow to describe all colors
both theories are currently supported with regard to how we perceive color
theorists suggest that early stages of color processing is trichromatic whereas later stages of processing is opponent process
50
complimentary colors are
colors that make grey tones when mixed together
51
afterimage is a
visual image that persists after the stimulus is removed
the color of the afterimage will be the compliment of the color you originally stared at
52
define color blindness
encompasses a variety of deficiencies in the ability to distinguish among colors
occurs more frequently in men than women
complete blindness to colors is quite rare
most are dichromates so they make do with only 2 color channels
53
have their been studies suggesting that color affects behaviour
yes. red test = poorer scores cause it reminds the student of being marked
red dress is more attractive
re seems to move faster on a sightline
54
a reversible figure is a
drawing that is compatible with two interpretations that can shift back and forth
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a perceptual set is a
readiness to perceive a stimulus in a particular way
as a result perception involves much more than passively receiving signals from the outside world, it involves interpretations of sensory input
56
inattentional blindness which likely happens when
people work on a task that requires a lot of attention or create a heavy perceptual load and something else really obvious gets blocked out
it's similar to "not listening" when someone is talking to you
57
feature analysis is
the process of detecting specific elements in visual input and assembling them into a more complex form
start with components / lines edges / corners that get turned into perception of more complex shapes and things
58
bottom up processing is a
progression from individual elements to the whole
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top-down processing relates to a
progression form the whole to the elements
reading words before detecting letters, for instance
60
Define subjective contours
the perception of contours where none actually exist
61
Describe the phi phenomenon
the illusion of movement created by presenting visual stimuli in rapid succession
film
62
Define figure-ground relationship
the figure is the thing being looked at and the ground is the background against which it stands
figures seem to have more substance and shape and appear closer
seem to stand out in front
63
What is a reversible perspective
the two faces looking at each other or the vase, depending on how you see it, but you can't see both at the same time
64
gestalt concept of proximity
things that are close to one another seem to belong together
in the example provided, people perceive rows, not columns because the dots are closer together in rows
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gestalt concept of closure
we group elements to create a sense of closure
if there are gaps between lines of a cat, then we see the whole cat
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gestalt concept of similarity
elements that are similar tend to be grouped together
67
gestalt concept of simplicity law of pragnaz
good form. we tend to simplify a form
in this example it's a bunch of lines, but we tend to see a rectangle over a triangle
68
gestalt concept of continuity
tend to see elements in ways that produce smooth continuation/direction and people tend to follow in ways that they have been led
69
Differentiate distal stimuli and proximal stimuli as they relate to visual perception
distal stimuli are stimuli that lie in the distance (things outside of your body)
proximal stimuli the stimulus energy that impinge directly on the sensory receptors (light falling on your retinas)
70
define perceptual hypothesis
an inference about which distal stimuli could be responsible for the proximal stimuli sensed
as you move the square away from you it becomes a trapezoid but you still perceive it as a square so your brain is doing something to compensate and this is called perceptual hypothesis
an example of top down
71
deine depth perception
involves interpretation of visual cues that indicate how near or far away objects are
72
2 kind sof depth perception are:
binocular depth cues
| monocular depth cues
73
retinal disparity refers to
objects project images to slightly different locations on the right and left retinas so the right and left eyes see slightly different views of the object
an object within 25 feet projects images to slightly different locations on your R and L retina
the closer the object, the more retinal disparity there is
this is why the wagon in front of you seems to have more depth than the mountain in the distance
74
convergence involves
sensing the eyes converging toward each other as they focus on closer objects
the more your eyes need to converge toward each other when looking at an object, the closer the object must be
75
motion parallax involves
images of objects at different distances moving across the retina at different rates
the fence going by when you're driving - it goes by faster cause it's closer
this is an example of active use of the eye whereas the pictoral depths don't need active use
76
accommodation happens when
the change in lens shape happens as a result of objects getting closer it is another account for sensing depth
77
pictorial depth cues
clues about distance that can be given in a flat picture
78
name the 6 pictorial cues
interposition: if an object comes between you and another object it must be closer to you
relative size: closer objects appear larger
linear perspective: parallel lines converge in the distance, so it give us a sense of distance
texture gradients: details of textures of things that are closer are more defined or coarser and details of objects that are further away are smoother
light and shadow: gives depth (example of the crater vs mound)
height in plane: distant objects appear higher in a picture whereas closer objects are lower in the visual field
79
perceptual constancy is a
tendency to experience a stable perception in the face of continually changing sensory input
eg: someone is coming closer to you so they seem bigger but you don't assume they are growing
in the ames room we assume that its a rectangle room, but it's not
80
define optical illusion
an apparently inexplicable discrepancy between the appearance of a visual stimulus and its physical reality
Müller-Lyer illusion: if two lines cast equally long retinal images but one seems farther away then the more distant one is a assumed to be longer
The Ames room is a room with different heights and distances that makes two things in front of you seem bigger or smaller
81
impossible figures are
objects that can be represented in 2D pictures but cannot exist in 3D space
Escher
82
Goodale experiment
a study of "DF" who suffered brain damage
she could grasp a pencil but not able to identify it
she couldn't copy a photo of an apple but she could create it from a memory
concluded that there are two vision pathways to the brain: ventral stream determines the perception of the external world
dorsal stream for the visual control of action
83
sound waves are
vibrations of molecules moving through air
84
pitch is measured by
Frequency is cycles per second (Hz)
85
loudness is measured by
Amplitude (dB)
perceived loudness doubles every 6-10 decibels
there is an interplay between dB and Hz in terms of absolute threshold
frequencies between 1k and 5k yield the lowest absolute threshold because the human ear is most sensitive to sounds in this range
86
the factor that determines timbre
purity
87
how many parts of the ear are there?
inner, middle and external
88
define pinna
a sound collecting cone on external ear
89
where is the auditory canal
middle ear
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define eardrum
a taut membrane that vibrates in response to sounds from auditory canal (middle ear)
91
3 tinniest bones in ear are called
stirrup hammer anvil (ossicles) they amplify change sin pressure (middle ear) also known as the malleus, incus, and stapes
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cochlea
(greek for spiral shelled snail) a fluid-filled, coiled tunnel that contains the receptors for hearing (inner ear)
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oval window
lies behind and is vibrated by the stirrup
is a membrane-covered opening that leads from the middle ear to the vestibule of the inner ear.
Vibrations that contact the tympanic membrane travel through the three ossicles and into the inner ear. The oval window is the intersection of the middle ear with the inner ear
94
basilar membrane
neural tissue that runs the length of the spiraled cochlea, holds the auditory receptors
the auditory receptors are called hair cells because of the tiny bundles of hairs that protrude
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functioning of the inner ear
waves in the fluid of the inner ear stimulate the hair cells analogous to rods and cones, the hairs convert the physical stimulation into neural impulses
then on to the thalamus and auditory cortex in the temporal lobe
evidence suggests there are specialized cells like feature detectors as well as parallel processing of signals
96
place theory with regard to pitch
holds that perception of pitch corresponds to the vibration of different portions or places along the basilar membrane
both theories are correct in that the whole membrane vibrates together, but certain frequencies cause certain areas to have more response than others
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frequency theory with regard to pitch
holds that perception of pitch corresponds to the rate or frequency at which the entire basilar membrane vibrates
both theories are correct in that the whole membrane vibrates together, but certain frequencies cause certain areas to have more response than others
98
2 main factors in auditory localization
intensity (loudness)
and the timing of sounds arriving at each ear
with the second one, we measure the difference in time it takes to get to the ear that is furthest away from the sound, and that helps us to account for distance
the head cause a baffle shadow, which also dampens the dB to a certain degree in one ear over the other, so there is a corresponding measurement in dB from one ear to the other.
99
list steps in gustatory process
food/drink = chemical substances that are water soluble
gustatory receptors are clusters of taste cells found in the taste buds that line the trenches around the tiny bumps on the tongue
when chemicals get dissolved in saliva and are absorbed they trigger neural impulses –> thalamus –> insular cortex in frontal lobe
taste cells have a short life - 10 days then new ones take their place
100
four primary tastes and the fifth taste some scientists have suggested be added?
sweet, sour, bitter, salty and
| umami - meat and cheeses
101
define flavor
the combination of taste, smell and the tactile sensation of food in ones mouth
102
Describe the routing of olfactory information
similar to taste in that the stimuli are volatile chemicals (evaporate) that dissolve in fluid - in this case in the mucus
the receptors are olfactory cilia located in the upper portion on the nasal passage
receptors have axons that synapse with cells in the olfactory bulb and then routed to various spots in the cortex
short life span an constantly being replaced at about 30 - 60 days
only sense to not go through the thalamus
The olfactory bulb (bulbus olfactorius) is a neural structure of the vertebrate forebrain involved in olfaction, or the sense of smell. Flow of olfactory information from receptors to glomeruli layer.
103
pheromones are
chemical messages typically imperceptible that can be sent by one organism and received by another member of the same species
linked to physical attraction and sexual activity
104
why do humans have fewer olfactory receptors?
evolution probably just allocated more and more to vision
105
Describe the structures and functions involved in feeling pressure
mechanical, thermal and chemical
path is through spinal cord –> brainstem –> fibres cross over to opposite sides –> through thalamus –> into somatosensory cortex in parietal lobe
cells in the nervous system are sensitive to specific patches of the skin
physical stimuli for touch are
they vary considerably in size and are the touch equivalent to receptive fields in vision - often involving a center surround arrangement (stimuli falling in the centre often produce opposite effect of stimuli falling in the surrounding area)
106
how are touch receptors similar to receptive fields in vision?
often involving a center surround arrangement (stimuli falling in the centre often produce opposite effect of stimuli falling in the surrounding area)
107
How many pathways are there for pain?
2
| fast and slow
108
fast pathway re pain
registers localized pain and relays to the cortex in a fraction of a second
sharp pain when you cut your finger
thick myelinated neurons called A-delta fibres
*fast/sharp/myelinated because myelin speeds things up and A-Delta because A stands for the 1st row of pain*
109
slow pathway re pain
lags a second or two behind the other one
long lasting aching/burning that you feel after the initial pain
thin unmyenilated neurons called C fibres
110
Describe the gate-control theory of pain
holds that incoming pain sensations must pass through a "gate" in the spinal cord that can be closed, thus blocking ascending pain
(thumb is cut so pain, but then baby in trouble and you stop feeling your pain in thumb and tend to baby)
the gate is not anatomical, but a pattern of neural activity
pain is a multidimensional phenomenon produced by many influences
111
periaqueductal gray in the mid-brain (PAG) serves to modulate pain - how?
this area is initiated by endorphins that trigger impulses which eventually release serotonin and then go down the spine and release more endorphins, curbing the pain
when this pathway is cut, analgesic effects of morphine are curbed and when it is stimulated, the analgesic effects are heightened, so it may be that "gate" area
112
What is the kinesthetic system
monitors the positions of the various parts of the body
receptors located in joints as in how much are they bending
also located in muscles as in registering tautness or extension
113
Describe the structures and functions of the vestibular system
responds to gravity and keeps you informed of your body's location in space
provides a sense of balance and equilibrium compensating for changes in the body's position
located in the inner ear in 3 semi-circular canals filled with fluid
shifts in the fluids are detected by hair cells like the ones in the cochlea
114
door in the face technique
making a large request that is likely to be turned down as a way to increase the chance that people will agree to a smaller request later
115
contrast effect
is lightning a candle in a dark room - seems brighter than lighting the second candle
116
what are comparitors
people, objects, events and other standards used as a baseline for comparison in making judgements
if you're judging your own beauty and you just watched TV with supermodels, you might not feel so hot
we often use these
