Sensation Flashcards
1
Q
Senses (what is it? how many?)
A
- how we experience the world
- 5 basic senses, but we have many more (ie. subgroups of somatonsensory)
2
Q
Importance of audition, vision and smell, and taste and touch
A
- Audition important for social behaviour
- Vision and smell give us info about distant events
- Taste and touch give us info about immediate, nearby events
3
Q
sensation
A
- detecting STIMULI (brightness, colour, warmth)
- Ie. Seeing the colour red
4
Q
perception
A
- detecting OBJECTS (apples, chairs, soccer balls)
- Ie. Seeing a red apple
5
Q
transduction
A
sense organs converting energy from environmental events into neural activity that the brain can respond to
6
Q
role of sense organs in transduction
A
detect stimuli, then transmit it to the brain via neural impulses -> brain analyzes these impulses to reconstruct what has occurred
7
Q
role of receptor cells in transduction
A
respond to physical stimuli like light, vibrations, etc.
8
Q
anatomical coding
A
- interpreting the LOCATION and TYPE of stimulus (depends on which nerve fibers are active)
- Ie. Rubbing eyes -> stimulate light-sensitive receptors -> brain doesn’t know that those receptors were stimulated by a non-visual stimulus -> we see stars and flashes
9
Q
temporal coding
A
- encoding INTENSITY (time/rate)
- The rate at which neurons fire tells us how intense that stimulus is
10
Q
psychophysics (and what it relies on)
A
- study of relation between physical characteristics of stimuli and the sensations they produce
- Rely on thresholds (line between perceiving and not perceiving)
11
Q
difference threshold
A
minimum detectable DIFFERENCE BETWEEN 2 STIMULI
12
Q
absolute threshold
A
minimum VALUE OF A STIMULUS that can be detected
13
Q
just-noticeable difference (JND)
A
Weber measured this - smallest change in stimulus that a person can detect (aka: difference threshold)
14
Q
weber fractions
A
different ratios of the just-noticeable difference
15
Q
How did Fechner use the JND system?
A
to measure people’s sensations - used lights behind frosted glass, brightening one of them until person could tell the difference -> showed how a logarithmic function could be derived from Weber’s principle
16
Q
signal detection theory
A
Every stimulus requires discrimination between signal and noise
17
Q
signal (in signal detection theory)
A
stimulus
18
Q
noise (in signal detection theory)
A
background stimuli and random activity of nervous system
19
Q
response bias (in signal detection theory)
A
tendency to say yes or no (ie. When a light flashes and you have to say whether or not it was accompanied by a tone)
20
Q
hit
A
saying yes when the stimulus was presented
21
Q
miss
A
saying no when the stimulus was presented
22
Q
correct negatives
A
saying no when the stimulus was not presented
23
Q
false alarms
A
saying yes when the stimulus was not presented
24
Q
manipulation of response bias
A
Examples:
- promising the participant a dollar every time they make a hit with no penalty for false alarms -> they would say yes all the time
- giving them a dollar for every hit but fine a dollar for every miss -> will be very conservative with their answers
25
receiver operating characteristic curve
a graph of hits and false alarms of participants under different motivational conditions; detects a person's ability to detect a particular stimulus
26
light
stimuli that consists of radiant energy that has wavelengths between 380 and 760 nm
27
wavelength
- distance between adjacent waves of radiant energy
- different visible wavelengths have different hues/colours
- we can't see invisible wavelengths like UV, X, Gamma, etc. but some animals can (ie. bees can see UV, snakes can see infared)
28
electromagnetic spectrum
entire range of wavelengths
29
visible spectrum
the wavelengths our eyes can detect and see as light
30
eye is protected by
- eye-sockets
- eyelid (keeps out dust and dirt)
- eyelashes (keep stuff from falling in eye)
- eyebrows (prevent sweat from dripping into eye)
- reflexes (automatic eyelid closure and withdrawal of head)
31
cornea
transparent tissue covering front of the eye, admits light
32
sclera
tough other layer of eye; the "white" of the eye
33
iris
pigmented muscle of the eye that controls the size of the pupil and thus the amount of light emitted into the eye (brain controls the 2 muscles in the pupil)
34
aqueous humor
- fluid-filled space behind the cornea; filters fluid from blood to nourish cornea and other parts of eye
- problem with aqueous humour can cause glaucoma
35
how does the eye view things
upside-down and reversed from left to right, but the brain compensates for this and interprets it appropriately
36
lens
- transparent organ situated behind iris of eye; helps focus image on the retina
- as people age, it becomes less flexible -> vision become fuzzier and less focused
37
accomodation
changes in thickness of the lens that focus images of near or distant objects on the retina
38
nearsightedness
- eyes are too long
- image focused in front of fovea
- require concave lenses
39
farsightedness
- eyes are too short
- image focused behind fovea
- require convex lenses
40
retina
- tissue at the back of the eye that contains photoreceptors and associated neurons; performs sensory functions
- no photoreceptors in front of optic disk -> this part of retina is blind
41
photoreceptors
receptive cell for vision in the retina (either rod or cone) that transduce light into neural activity
42
optic disc
at back of eye; information from photoreceptors is sent here before going to optic nerve and then to brain
43
Order in which light passes through retina
1. ganglion cell layer
2. bipolar cell layer
3. photoreceptor layer
44
Order in which visual information passes to brain
1. photoreceptor layer
2. bipolar cell layer
3. ganglion cell layer
45
bipolar cell
neuron in the retina that receives information from photoreceptors and passes it on to the ganglion cells, from which axons process from optic nerves to brain
46
ganglion cell
neuron in retina that receives info from photoreceptors by means of bipolar cells and from which axons proceed through the optic nerves to the brain
47
rod
photoreceptor that is very sensitive to light but cannot detect changes in hue
48
cone
photoreceptor that is responsible for acute daytime vision and colour perception
49
fovea
- small pit near centre of retina only containing densely packed cones; responsible for most acute and detailed vision
- farther away from fovea = less cones and more rods
50
photopigment
- complex molecule found in photoreceptors; when struck by light, it splits and stimulates the membrane of photoreceptor in which it resides
- human eyes contain 4 kinds (1 for rods, 3 for cones)
- after it splits, it becomes bleached; then it recombines and is ready for light again
51
rhodopsin
pink photopigment contained by rods
52
what is responsible for transducing light into neural activity?
chemical reactions
53
dark adaptation
process of the eyes becoming capable of distinguishing dimly illuminated objects after going from a bright area to a dark one (at first, photopigments are bleached so there aren't many left to respond to dim light, so you can only make out objects in the dark once they regenerate)
54
eye movement and Riggs, Ratliff, and Cornsweet's experment
- eyes are never still, always slightly moving
- experiment used mirrored contacts to ensure eye always focused on image even when it moved -> some details began to blur/fog -> elements of visual system aren't responsive to unchanging stimuli and eventually cease to respond -> our eyes slight movements prevent our vision from blurring while we focus on something
55
3 types of the eye's purposive movements
1. vergence movements
2. saccadic movements
3. pursuit movements
56
vergence movements
co-operative eye movement that ensure that the image of an object falls on identical portions of both retinas
57
saccadic movements
rapid movement of the eyes that is used in scanning a visual scene
58
pursuit movements
used to follow a moving object and maintain its image on the fovea
59
who has colour vision
- birds
- fish
- primates
60
what do spectral colours (like the ones in the rainbow) tell us about colour vision?
spectral colours don't include all the colours we can see, so differences in wavelength don't account for all the differences in the colours we can perceive
61
physical dimensions of colour
- wavelength
- intensity
- purity
62
perceptual dimensions of colour
- hue
- brightness
- saturation
63
hue
perceptual dimension of colour, most closely related to the wavelength of light
64
brightness
perceptual dimension of colour, most closely related to the intensity of radiant energy emitted by a visual stimulus
65
saturation
perceptual dimension of colour, most closely associated with purity of colour
66
colour mixing
perception of two or more lights of different wavelengths seen together as light of an intermediate wavelength
67
trichromatic theory
- proposed by Thomas Young, elaborated on by Helmholtz
- theory that colour vision is accomplished by three types of photoreceptors, each of which is maximally sensitive to a different wavelength of light (blue, green, and red)
68
opponent process
the representation of colours by the rate of firing of two types of neurons: red/green and yellow/blue
69
negative afterimage
image seen after a portion of the retina is exposed to an intense visual stimulus; a negative afterimage consists of colours complementary to those of the physical stimulus
70
why are males more likely to be colour-blind?
because genes for producing photopigments are found in the X chromosome, and men only have 1 while women have 2, so their defective genes will always be expressed
71
protonopia
form of colour-blindness caused by defective red cones in the retina (red cones filled w/green pigment)
72
deuteranopia
form of colour-blindness caused by defective green cones in the retina (green cones filled w/red pigment)
73
tritanopia
form of colour-blindness caused by lack of blue cones in the retina (most rare type of colour blindness)
74
sound
consists of rhythmical pressure changes in air that move the eardrum in and out
75
hertz
primary measure of frequency of vibration of sound waves; cycles per second
76
physical dimensions of sound
1. amplitude/intensity
2. frequency
3. complexity
77
perceptual dimensions of sound
1. loudness
2. pitch
3. timbre
78
pinna
- what we all refer to as the "ear"
| - flesh-covered cartilage that funnels sound through the ear canal to the inner ear
79
eardrum
- aka tympanic membrane
- vibrates back and forth in response to sound waves and passes these vibrations onto the receptor cells in the inner ear
80
ossicles
- a set of 3 bones that transmit vibrations of eardrum to the inner ear
- hammer/malleus; anvil/incus; stirrup/stapes
81
cochlea
snail-shaped, bony, liquid-filled structure that contains the receptive organ for auditory transduction
82
oval window
opening in the bone surrounding the cochlea, stirrup presses against this to transmits sound vibrations into cochlear fluid
83
basilar membrane
one of two membranes that divide the cochlea of the inner ear into 3 compartments; the receptive organ for audition resides here
84
round window
opening in bone surrounding cochlea, permits sound to be transmitted through oval window into cochlea
85
auditory hair cell
sensory neuron of auditory system; located in basilar membrane
86
cilium
hair-like appendage involved in transducing sensory info
87
tectorial membrane
located above basilar membrane, serves as a shelf against which cilia of auditory hair cells move
88
how do we perceive pitch?
- what kinds of neurons fire
- high and med frequencies of sound cause different parts of the basilar membrane to vibrate
- low frequencies cause only tip of basilar membrane to vibrate
89
how do we perceive loudness?
- rate of neuron firing
| - louder sounds -> more vibrations -> more rapid firing of neurotransmitters
90
harmonics/overtones
a series of tones where the frequency is a multiple of the fundamental frequency
91
fundamental frequency
the lowest/most intense basic pitch of sound
92
timbre
- complexity of a sound
| - harmonics and fundamental frequency combined
93
what we use to locate source of sound
- relative loudness (appears louder to ear facing the sound)
- difference in arrival time (whether the sound waves cause one ear to be pushed in while the other is pushed out [noise from r or l side], or if they move in synchrony [noise in front])
94
masking-level difference
- ability to use background info to process a sound (ie. not being able to hear a conversation in a noisy room)
- less MLD = indication of hearing loss
95
chemosenses
- senses that detect chemicals in environment
| - taste (gustation) and smell (olfaction)
96
how is flavour different than taste?
flavour includes odour, texture, and touch as well as taste
97
papillae
small bump on tongue that contains taste buds
98
taste bud
small organ on tongue that contains group of gustatory receptor cells
99
microvilli
hair-like projection on taste buds, interact with molecules of substances dissolved in saliva
100
5 senses and their qualities
- salty (ionize when dissolved; helps recognize sodium chloride, which helps regulate body fluids)
- sweet (non-ionizing molecules; recognize sugar content of energy-giving foods)
- bitter (non-ionizing molecules; recognize potential poison)
- sour (acids; recognize decomposing foods)
- umami (amino acids/proteins; recognize fuel-rich foods)
101
why is scent one of the most puzzling senses?
- people struggle to describe scents in words
| - scents can evoke old memories because the odour info is sent to limbic system, which aids in memory
102
what is the accessory olfactory system?
- our second olfactory system
| - detects pheromones
103
pheromones
chemical signs that regulate sexual and social behaviours
104
olfactory mucosa
mucus membrane lining the top of the sinus, contains cilia of olfactory receptors
105
olfactory bulbs
stalk-like structures located at the base of the brain that contain neural circuits that perform the first analysis of olfactory info
106
where is olfactory info sent (why is this different from other senses?)
- directly to the limbic system
| - different because other info is sent to thalamus and then to a specific region of the cerebral cortex
107
how can we detect tons of odours when we have limited odour receptors?
odours bind to more than one receptor -> brain receives signals from multiple receptors at once -> this pattern signals which odour it is
108
somatosenses
body sensations; sensitivity to touch, pain, temp, etc.
109
free nerve ending
dendrite of somatosensory neurons, surrounds our hair follicles
110
pacinian corpuscle
somatosensory nerve ending that detects mechanical stimuli ie. vibrations
111
touch vs. pressure
- touch: sensation of light contact of an object with the skin
- pressure: sensation produced by more forceful contact
112
two-point discrimination threshold
minimum distance between two small points that can be detected as seperate stimuli when pressed against a particular region of the skin (smaller distance on lips and fingers, larger on forearm)
113
why does menthol produce a cooling sensation?
because it stimulates a thermal receptor and produces neural activity that the brain interprets as coolness
114
3 types of pain receptors (aka nociceptors) in skin
1. detect intense pressure (ie. hitting, stretching, pinching of skin)
2. detect extremes in heat or acids
3. detect ATP (which is present in tumour growth... ie. cancer, muscle damage, etc.)
115
pain is made up of ____ and ____; drugs that affect pain
- sensation and emotion
- some drugs diminish sensation of pain (ie. morphine) while some drugs just diminish emotional reaction to ie (ie. valium)
116
phantom limb and its significance
- amputees feel sensations in a limb that has been amputated
| - suggests our brains are programmed to provide sensations for all 4 limbs, even if we don't have them
117
muscle spindles
muscle fibre that functions as a stretch receptor; detects changes in muscle length
118
vestibular apparatus
receptive organs of the inner ear that contribute to balance and perception of head movement
119
semicircular canals
a set of 3 canals in the inner ear that contain a liquid, which flows in response to head movements
120
vestibular sacs
have crystals that respond to head movements
121
3 organs in our ear that help keep us balanced
- vestibular apparatus
- semicircular canals
- vestibular sacs
