1
Q
Sensation vs perception
A
Sensation refers to how your senses transform physical properties of the environment and body into electrical signals relayed to the brain (also called ‘transduction’)
Perception is the process of organizing, selecting, and INTERPRETING these signals (active)
2
Q
sensation meaning
A
how your senses transform physical properties of the environment and body into electrical signals relayed to the brain (also called ‘transduction’)
3
Q
six senses in humans
A
Vestibular – inner ear senses gravity and movement
Vision – receptors in eyes respond to light
Hearing – receptors in ears respond to sound and vibrations
Somatosensation – the awareness of the body
Taste – receptors on tongue respond to chemicals
Smell (Olfaction) –receptors in the nose respond to chemicals
4
Q
Perception meaning
A
the process of organizing, selecting, and interpreting signals from our senses
5
Q
T/F: Perception is the ‘registration’ of what exists in the world
A
False
It’s an ACTIVE process of organizing information into meaningful (useful) representations of the world
6
Q
Perception is an active or passive process?
A
It’s an ACTIVE process of organizing information into meaningful (useful) representations of the world
7
Q
Segmentation and grouping in terms of perception of information is where what happens?
A
Our brain can select key features to recover complex information about objects and make sense of the sensory information it receives
8
Q
what is the problem of qualia
A
why do our experiences of stimuli have the qualities that they do? i.e. how can we differentiate between types of stimuli from our senses
eg. why does vision evoke a certain experience that is different to sound
All of our different senses transform their physical input into the same ‘currency’: electrical impulses in the brain, so why do we experience one set of electrical impulses as sight, and others as sounds, flavors, smells, touch, pain, or a sense of balance? How does the brain know what is causing the stimulation it receives? And what can happen if it gets this ‘wrong’ or ‘mixed up’?
9
Q
what is Synesthesia
A
when the ‘lines’ between types of stimuli/senses get crossed or are somehow not fully separated
10
Q
Most common form of synesthesia
A
Grapheme-color synesthesia – letters/numbers/sounds have colours associated
11
Q
Significance of illusions – what do illusions demonstrate about perception
A
Illusions demonstrate the active processes the brain deploys to interpret images
They provide insight into contexts where the visual system goes beyond the information in the input
Reveals the general rules the visual system uses to extract information about the physical world Importance of illusions
12
Q
What can happen if the brain gets this distinction between stimuli/senses ‘wrong’ or ‘mixed up’?
A
synesthesia
13
Q
what are Illusory figures
A
where the brain constructs the whole image from the parts it has
14
Q
T/F: The visual system can generate percepts of illusory volumes
A
true
15
Q
dimensionality problem of Chemical senses (Taste, Smell, and Flavor)
A
Very large number of chemicals but we only have a finite sized sense organ with finite amount of receptors to detect them
16
Q
solution to the dimensionality problem of Chemical senses (Taste, Smell, and Flavor)
A
Must collapse the large number of chemicals into a few biologically relevant dimensions (have 5 for taste, about 400 for smell)
17
Q
how many biological dimensions are there for taste?
A
5
18
Q
how many biological dimensions are there for smell?
A
~400
19
Q
Flavour = ?
A
Taste + Smell + Temperature
20
Q
4 types of papillae on the tongue (EXTRA)
A
Fungiform (resembles tiny mushrooms), visible to the eye on the anterior portion of tongue. Huge variation between people
Filiform: no taste function, located at the anterior portion of tongue (tip). Different shapes in different species (e.g., cats). Draws in food and acts as an abrasive (most numerous)
Foliate: sides of the tongue; look like folds, taste buds buried in the folds
(Circum)vallate: large visible structures like an inverted V on the back of tongue. Look like islands surrounded by moats
21
Q
T/F: there are no taste buds on the roof of mouth where soft and hard palates meet
A
false
22
Q
Labelled-line model is better than the cross-fibre model of the tongue’s taste receptors. What does the labelled line model say?
A
each fibre corresponds to a different taste dimension
23
Q
Labelled-line model is better than the cross-fibre model of the tongue’s taste receptors. What does the cross-fibre model say?
A
each fibre has all the taste dimensions
24
Q
5 primary taste sensations/dimensions:
A
Sweet: identify energy rich nutrients
Salty: maintain electrolyte balance
Sour: acidity (dangerous at high levels, rotten food)
Bitter: potential poison (huge class)
Umami (savoury): detection of amino acids (MSG and aspartate)
25
are the 5 primary taste sensations/dimensions intrinsic properties of the chemicals?
no, they are just biological interpretations
26
Innate preference for what taste sensation? why
sweetness: purpose is to gain enough energy to grow a body (sweet things tend to be high in calories)
27
T/F: Taste discrimination does not change much with age
true
28
T/F: Taste preference does not change much with age
false
29
T/F: Sensitivity to different tastes varies
true
30
Detection thresholds for different taste dimensions
Sweetness: one part glucose in 200
Saltiness: in one part NaCl in 400
Sourness: in one part HCl in 130,000
Bitterness: in one part Quinine in 2,000,000
31
Sensitivity to a taste dimension is proportional to?
its potential to be dangerous
32
Super-Tasters have more what?
more fungiform taste receptors around the tip and sides of their tongue
33
Super-Tasters are identified using?
6-n-propylthiouracil (PROP)
34
% PROP Non-Tasters Across Cultures ranged from what to what?
1.2% in Indonesia to 73% in France
35
Demographics of super-tasters and non-tasters
Females have more Super-Tasters and fewer Non-Tasters than males
Asian Australians have more Super-Tasters and fewer Non-Tasters than caucasians
36
taste sensitivity (super-tasters and non-tasters) is genetic
yes, this is likely
Similarity between sensitivity of Asians living in and out of Australia, suggesting a genetic rather than cultural influence
37
T/F: Spicy is NOT a taste
true
Spicy sensations are actually pain and temperature from chemosensory irritation signaled by the trigeminal nerve
38
T/F: Taste doesn’t always require the presence of the taste experienced
true
Eg. “miracle fruit” (Synsepalum dulcificum): binds to taste buds. At low pH, miraculin binds proteins and activates sweet receptors
Eg. “pine mouth”
39
function of papillae on the tongue
enabling taste perception through their taste buds
40
which types of papillae on the tongue have taste buds?
fungiform, foliate, (circum)valiate
41
olfaction provides information about chemicals located where?
suspended in the air around us
42
how many channels for smell in humans
~400
43
smell in Dogs vs humans
Dogs have a much bigger olfactory bulb and nose so sample more air and have a larger surface are for mucus to dissolve odor molecules
Dogs have up to 300 million nerve cells to detect odors whereas humans have 5 million
44
Shape pattern theory of olfaction
Odorants and odorant receptors have different shapes which bind and cause activation if their shapes match
45
olfactory adaptation occurs because?
We cannot escape the smell of ourselves
46
olfactory adaptation results in higher sensitivity to?
We are more sensitive to smells that are not our own (e.g., produced by potential mates)
47
give examples of olfactory adaptation
We are more sensitive to smells that are not our own (e.g., produced by potential mates)
Eg. Smokers are usually unaware of the smell of smoke on themselves until they quit smoking
48
Smell and age
Sense of smell increases in childhood and early adulthood, but decreases starting in middle age
49
Starting in middle age, what happens to our odour sensitivity?
Need more concentrated odour to detect it, and once detected it will be judged as less intense.
50
Starting in middle age, what happens with our odour adaptation speed and duration?
Process of odour adaptation (which makes us no longer smell strong odours after a while) occurs sooner and lasts longer for older adults
51
what is olfactory adaptation?
the process where the sense of smell becomes less sensitive to a persistent odor, making it fade or disappear over time
52
most flavour comes from smell or taste?
smell
53
Exteroception
information about the external world beyond the body boundary.
54
Proprioception
information about the disposition of the body itself, and particularly the position of one body part relative to another.
55
Interoception
information arising from receptors within the core internal organs of the body, such as the heart, lungs and gut.
56
2 major subsystems of the somatosensory system
Detection of mechanical stimuli
Detection of pain and temperature
57
Mechanosensory processing involves what receptors to detect external stimuli?
cutaneous and subcutaneous mechanoreceptors at the body surface
58
Mechanosensory processing involves what receptors to detect internal stimuli?
Proprioceptors
59
Tactile Afterimages
Opponent-like after-effects: texture contrast after-effects (after touching something rough, a medium rough surface feels smoother); can be observed for temperature as well.
60
Tactile adaptation
Importance of movement in perceiving spatial patterns in the skin; stabilized (i.e., non-moving) objects on the skin are less salient than when the skin is first perturbed
61
Active versus Passive Touch perception level
The tactile system has evolved to perceive best when it is exploring.
62
T/F: all somatosensory receptors work in the same way
True
Stimuli applied to the skin deform or otherwise change the nerve endings, which in turn affects the ionic permeability of the receptor cell membrane. This induces a depolarizing current in the nerve ending, which triggers action potentials (sensory transduction).
63
Stimuli applied to the skin deform or otherwise change the nerve endings, which in turn affects?
the ionic permeability of the receptor cell membrane
64
Stimuli applied to the skin deform or otherwise change the nerve endings, which in turn affects the ionic permeability of the receptor cell membrane. This induces ?
a depolarizing current in the nerve ending, which triggers action potentials (sensory transduction).
65
3 functional groups of somatosensory receptors
mechanoreceptors
nociceptors
thermoreceptors
66
Proprioceptors location
in muscles, joints, and other deep structures monitor mechanical forces generated by the musculoskeletal system
67
examples of proprioceptors
Eg. muscle spindles provide information about muscle length
Eg. Golgi tendon organ provides information about muscle tension
Eg. join receptors provide information about the positions and tensions on the joints (contain four different kinds of receptors)
68
Two-point thresholds tell you information about
size of the receptive fields (somatosensory)
69
what is the Two-point threshold?
Minimal separation between two-points needed to perceive them as separate
70
2 general types of Mechanosensory touch fibers
Rapidly adapting
Slowly adapting
71
rapidly adapting mechanosensory touch fibres convey information about?
change or dynamical quality of stimuli
72
slowly adapting mechanosensory touch fibres convey information about?
shape, edges, rough texture, persisting features
73
rapidly adapting mechanosensory touch fibres examples
Meissner corpuscles
Located at dermal papillae
Low-frequency vibrations
Pacinian corpuscles
Located in subcutaneous tissue and gut
Vibrations and/or tickle
High-frequency vibrations
74
slowly adapting mechanosensory touch fibres example
Merkel disks
Located in stratum basale
Dense in fingertips, lips, external genitalia
Light pressure
75
Consequence of not having either rapidly or slowly adapting mechanosensory touch fibres not working locally:
Local anesthesia
76
in Local anesthesia, absence of sensation is attributed to the body or the world? why?
the world
The response of these fibers provide information about the external world, not the self
77
Nociceptors terminate in?
unspecialised free endings
78
Nocireceptors categorized according to
the properties of the axons associated with them
79
nocireceptor categories
Aδ: myelinated axons, conduct at 20 m/s
Acute and sharp pain
C fibers: unmyelinated axons, which conduct at 2 m/s
Diffused pain
80
Aδ nociceptors are myelinated or unmyelinated?
myelinated
81
C fibres (nociceptors) are myelinated or unmyelinated?
unmyelinated
82
Aδ nociceptors relay what type of pain?
acute and sharp
83
C fibre nociceptors relay what type of pain?
diffused
84
3 calsses of nociceptors in skin
Aδ mechanosensitive nociceptors
Aδ mechanothermal nociceptors
Polymodal nociceptors (C fibers, quite slow)
85
example of Polymodal nociceptors (C fibers, quite slow) use
Eg. hot peppers activate a subset of C-fibres
86
Hyperalgesia
enhanced sensitivity to pain stimuli over time
87
T/F: Pain is the only sense that exhibits an enhanced sensitivity to pain stimuli over time
true
all other senses exhibit adaptation (decreased sensitivity) to the same stimulation.
88
T/F: Chronic pain can grow in psychological intensity over time.
true
89
Receptors for the transmission of visceral pain are conveyed centrally via neurons which also code for?
cutaneous pain through a dorsal column pathway
90
Stimulus quality (i.e. what it is and where it is) in the somatosensory system depends on?
the receptors that respond and where they project to
91
Stimulus quantity in the somatosensory system depends on?
the number of action potentials generated
92
what is the sensory homunculus
a somatosensory map/representation of the cortex saying stimuli at one point of the body stimulates a specific region in the cortex
93
vestibular system functions
control of gaze and posture
94
The inner ear contains sensory structures with receptor cells that detect ?
gravitational forces, including angular and linear head accelerations in space
95
Vestibular sense organs
5 sensory organs in the labyrinth of each ear
96
what are the 5 sensory organs in the labyrinth of each ear in the vestibular system
3 semicircular canals (SCCs) – angular accelerometers
2 otoliths – linear accelerometers
97
3 semicircular canals in the vestibular system measure ?
angular acceleration
98
2 otoliths in the vestibular system measure?
linear acceleration
99
Bending a vestibular hair-cell receptor in its preferred direction does what?
excites the neuron
100
Bending a vestibular hair-cell receptor in its opposite direction does what?
inhibits the neuron
101
Spinning can lead to dizziness, nausea, etc even after the spinning itself because?
fluid flowing in the SCCs bends the cupula and underlying hair cells
102
The vestibuloocular reflex (VOR)
Head movements require precise and rapid compensatory (directly opposite) eye movements in order to stabilise the images of objects on the retina
103
Fastest reflex arc built into the brain is?
The vestibuloocular reflex (VOR)
104
Amplitude – Gives rise to the percept of?
loudness
105
loudness is measured in
decibels (log 10 scale)
106
The reference sound level (I0) is?
the accepted minimum detectable sound level for humans at a particular frequency
107
Frequency – Gives rise to the percept of?
pitch
108
Purity of a sound wave – Gives rise to the percept of?
timbre
109
loudness is determined by
amplitude
110
pitch is determined by
frequency
111
timbre of sound is determined by
purity
112
Middle ear function
impedance matching
113
Eustachian tube in middle ear -- function
ensures the air pressure in the middle ear is the same as the atmospheric pressure outside the eardrum which is needed for transduction to occur
114
what is needed for transduction of sound waves to occur?
air pressure in the middle ear is the same as the atmospheric pressure outside the eardrum
115
Middle ear transmits eardrum vibrations to?
the oval window
116
Oval window transmits eardrum vibrations to?
fluid-filled cochlea
117
oval window vs eardrum size
oval window is 20x smaller
118
perception of pitch organisation
Organized like a helix: it wraps around to the same note (to your brain, not in physics), and octave higher, over the range of audible frequencies
119
3 Ossicles
malleus, incus, stapes
120
what happens to most incoming sound in the middle ear?
reflected rather than transmitted
121
Inner ear is filled with?
perilymphatic fluid
122
perilymphatic fluid has more or less resistance than air? what does this mean about the mechanical energy required to transmit sound waves?
more
Greater mechanical energy is required to transmit sound waves through the denser fluid filling the cochlea
123
pitch of different frequencies uses what scale?
logarithmic
124
with regards to pitch, doubling of frequencies is separated by?
an octave
125
oval window vibrations cause what to vibrate?
basilar membrane
126
Movement of the basilar membrane causes the what to move against the tectorial membrane?
hair cells
127
Movement of the basilar membrane causes the hair cells to move against the what?
tectorial membrane
128
Movement of the basilar membrane causes the hair cells to move against the tectorial membrane, which causes?
the cilia to bend
129
Movement of the basilar membrane causes the hair cells to move against the tectorial membrane, which causes the cilia to bend. What happens when the cilia bends?
hair cells release neurotransmitters onto synapses with auditory nerve fibers that send signals to the brain
130
Early theory (Rutherford) as to how the basilar membrane moves
moves at once like a diaphragm
131
Early theory (Rutherford): whole basilar membrane moves at once like a diaphragm. what was the issue with this?
basilar membrane varies in thickness and stiffness (high frequency stiff region at the base near the oval window, low frequency flexible region at the apex)
132
basilar membrane varies in thickness and stiffness -- describe the high frequency region
narrower, thicker, and stiffer at the base near the oval window, with shorter hair cells
133
basilar membrane varies in thickness and stiffness -- describe the low frequency region
wider, thinner, and more flexible at the apex wich longer hair cells
134
Bekesy’s observation about basilar membrane movement
Frequency sensitivity changes as you move along the basilar membrane due to its mechanical properties
135
The travelling wave from vibrations of the oval window peaks in different places depending on?
its frequency content
136
When the cilia bend, the hair cells release ?
neurotransmitters
137
When the cilia bend, the hair cells release neurotransmitters onto synpases with?
synapses with auditory nerve fibers that send signals to the brain
138
For low frequencies, auditory nerve spikes are phase-locked to?
the stimulus
139
For low frequencies, auditory nerve spikes are phase-locked to the stimulus
Degree of phase locking declines with?
frequency
140
Two cues to the frequencies in a sound:
1) The place of excitation in the cochlea.
2) The frequency of firing
141
White noise: the ultimate ‘broadband’ sound – contains what frequencies?
all frequencies at approximately equal amplitude
142
T/F: Instruments all generate the same component frequencies when played at a given pitch
true
143
instruments playing the same pitch differ in?
relative amplitudes of component frequencies
144
what contribute to timbre of music?
amplitude of the upper harmonics/component frequencies (or overtones)
145
The pitch of an instrument is mainly conveyed by the?
FUNDAMENTAL (or lowest) frequency
146
humans sing one note of a given pitch, consisting of?
the fundamental frequency, as well as a range of underlying upper harmonics (overtones)
147
Western musical scale is based on?
stacked 5ths
148
A fifth (the fifth note in the major scale) has a ratio of?
3:2
149
The octave is a ratio of?
2:1
150
All western musical instruments are ‘equal temperament’, which means?
errors are distributed -- only octaves are perfectly in tune
151
3 stages of vision
1. sample optical structure
2. transduce light energy into electrical impulses
3. transmit info to the brain for interpretation
152
The light returned from objects creates a set of?
nested rays of light
153
T/F: Different evolutionary strategies have emerged to sample the optical structure (a set of nested rays of light)
true
eg. eyes that are: compound, pinhole, single chambered, convex mirrors
154
what type of eye do humans have?
single chambered
155
in single chambered eyes, each region (point) of the world maps onto?
one receptor
156
with a convex lens, the focal plane varies as a function of?
lens curvature and object distance
157
eye accommodation involves?
Cornea performs most of the initial focusing of the incoming image
Lens changes shape to focus objects at different distances
158
what eye structure performs most of the initial accommodation/focusing?
cornea
159
what eye structure performs focus of objects at different distances?
lens
160
T/F: Not all depths can be simultaneously in focus
true
161
to focus light from a distant/near object, what eye structure changes and how?
Lens becomes “flatter” to focus light from a distant object on the retina or rounder to focus light from a near object on the retina
162
what helps the brain infer size and distance of objects?
light from depths that are different to the focused object is not focused
163
Two different classes of photosensitive receptors that operate in different luminance regimes
rods and cones
164
Scotopic vision is dominated by what photoreceptor and what level of light is it used in?
low-light, rod dominated
165
Photopic vision is dominated by what photoreceptor and what level of light is it used in?
high light, cone-dominated
166
Four types of photoreceptors
one rod, three cones
167
how many photons needed to stiulate a rod receptor?
only one
168
ratio of rods:cones by number
20 rods : 1 cone
120 million rods versus 6 million cones
169
what photoreceptor is responsible for our experience of color
cones
170
how many optic nerve fibres are there
1 million
171
Theories for why objects appear coloured
Trichromatic theory
Opponent processes
172
Trichromatic theory says different color experiences are due to ?
the activation of just 3 receptor (cone) types in different proportions
173
Opponent processes theory of colour perception says that?
Colour perception depends on six psychological primaries that are arranged in pairs
174
Evidence for Opponent Processes Theory:
We do not perceive reddish greens or bluish yellows
Colour aftereffects?
175
Colour-Vision Deficiencies is due to?
Defects in genes for making pigments in cones
176
3 main types of colour-vision deficiencies
red-green
blue-yellow
complete
177
People who suffer red-green deficiency are known as?
anomalous trichromats
178
anomalous trichromats demographic
more likely to be males because it is an X-linked trait
179
heredity of red-green colour blindness
X-linked
180
do anomalous trichromats (those suffering from red-green colour blindness) have all 3 cone types?
yes, but the L and M overlap more than they should
PSYC1002
flashcards
Decks in class (6)
# Cards
