Sensation and Perception Flashcards
1
Q
Sensation vs perception
A
Sensation: Parts of our surroundings (stimuli) that the brain analyzes and processes
Perception: When the brain uses stimuli to create an understanding of our surroundings
2
Q
Bottom-up vs top-down processing
A
Bottom-up: Perception of the world by processing physical messages delivered to the senses
Top-down: Perception of the world when one’s beliefs, memories and expectations are included
3
Q
Gestalt psych
A
Born organizing info in specific, predetermined ways that have usefulness
4
Q
Figure-ground principle
A
Other info is given priority over the background
5
Q
Proximity
A
Objects that are close together are grouped together
6
Q
Similarity
A
Objects that look like each other/similar to each other are grouped together
7
Q
Closure
A
Parts of object are missing but brain can still perceive a whole, coherent object
8
Q
Good continuation
A
Lines are perceived to continue themselves even when they cross each other and are interrupted
9
Q
Common fate
A
Objects that move together are grouped together
10
Q
Retina
A
Thin layer of tissue at back of eye that contains photosensitive receptor cells
11
Q
Cornea
A
Transparnet covering of eye and performs ~80% of focusing on a visual image
12
Q
Pupil
A
Hole in centre of eye where light enters and regulates entering by controlling relaxation/tension of muscles attached to iris
13
Q
Iris
A
Ring of pigmented tissue surrounding pupil and responsible for controlling its diameter and size, controlling light that reaches the retina
14
Q
Lens
A
Flexible tissue located behind pupil that focuses light on the retina
15
Q
Accommodation
A
When lens changes shape to bring objects into focus on the retina, which is determined by distance b/w eye and object (close = thick & round; far = relaxed & elongated)
16
Q
Myopia/nearsightedness
A
Eyes longer than average = focuses image before retina
17
Q
Hyperopia/farsightedness
A
Eyes shorter than average = focuses image after retina
18
Q
Sclera
A
White part of eye surrounding cornea
19
Q
Fovea
A
Part of retina behind pupil that contains many cones but no rods
20
Q
Optic nerve
A
Translates info from retina and sends it to visual cortex
Creates blind spot in vision b/c of part of retina it occupies
21
Q
Choroid
A
Has blood vessels and delivers nutrients to photoreceptors
22
Q
Anterior chamber aqueous humor
A
Liquid-filled space b/w cornea and iris and is routinely cleaned
23
Q
Virteous chamber virteous humor
A
Fluid-filled space that provides support and structure to eye and lens
24
Q
Photoreceptors/photoreceptive cells
A
Cells sensitive to exposure to light
25
Rods
- Most responsive to low-level light
- Mostly in retina's periphery
- Communicates/responds to amount of light, but not its qualities
- Compiles early processing about location of object & motion in surroundings
26
Cones
- Most responsibe to bright lighting conditions
- Chemically communicates info about acuity and colour
- A few million in fovea
- Only cells that communicate info about wavelength of object
27
Visual acuity
Transmitting info about fine detail
28
Refraction
Lens inverts image prior to brain perceiving it
29
Diffuse bipolar cells
Receive signals from rods and send messages to large/magno ganglion cells (M-cells)
30
Midget bipolar cells
Receive signals from cones and send messages to small/parvo ganglion cells
31
Small ganglion/parvo cells
- Receive signals from midget bipolar cells and axons leave cell to form part of optic nerve
- Sends signals about qualities of colour and detail
32
Large ganglion cells
- Receive signals from diffuse bipolar cells and axons leave eye to form part of the optic nerve
- Found in periphery
- Sends info about motion and visual stimuli in periphery
33
Light on center of ganglion receptive field vs. light on surrounding
Light on center = cell responds more rapidly
Light on surrounding = cell reduces firing
34
Optic chiasm
X-shaped structure where optic nerves from each eye cross before message is sent to thalamus
(Info from R side of BOTH eyes is sent to left hemisphere and vice versa)
35
Lateral geniculate nucleus
6-layered portion of thalamus that processes and organizes visual info
36
Visual striate cortex (VC)
Location in occipital lobe where visual info is organized and analyzed
37
Retinotopic organization
Spatial organization of retinal image is maintained through visual pathway
38
Simple cells
Feature-detecting cells that respond to lines on specific orientations
39
Complex cells
Cells that respond to lines in specific orientations in motion
40
Ventral/"what" stream
Info from occipital to temporal to identify object
41
Dorsal/"where" stream
Info from occipital to parietal to identify object location
42
5 steps of light passing through the eye to the visual cortex
1) Light waves enter eye through cornea then through pupil and when it hits the lens, it's focused toward the retina
2) Photoreceptors in retina transduces light energy into neural activity through the rods and cons, which turn light info into neurochemical signals
3) Transduced light creates action potentials that are sent along the optic nerves, which cross at the optic chiasm
4) After the optic chiasm, it's sent to the lateral geniculate nucleus (LGN) and visual info is processed in its 6 layers
5) Visual info is sent to the visual striate cortex (VC) and it's retinotopically/spatially organized in pattern we experience info
43
Short cones
Respond to short wavelengths (~450 nm, e.g. blue)
44
Medium cones
Respond to medium wavelengths (~530 nm, e.g. geen and yellow)
45
Long cones
Respond to long wavelenghts (~670 nm, e.g. red and orange)
46
Trichromatic theory
Proposes that colour info is identified by comparing activation of different conesin retina
47
Colour blindness
Born w/o a stype of cone
48
Opponent process theory
- Suggests that cells in visual pathway increase activation when receiving info from one type of cone and decreases when it sees the second colour
- Red and green
- Blue and yellow
- Black and white
49
Monocular depth/pictorial cues
Only need one eye to understand messages of depth
50
Occlusion
Object that's being partially blocked by another object is perceived as farther away
51
Relative height
Objects near horizon = appear farther away and objects far from horizon - closer
52
Relative size
When objects are about the same size, the one that's farther will take up a smaller portion of retina
53
Perspective convergence
Parallel lines that move farther away appear to converge
54
Familiar size
Judge distance based on prior knowledge of object's size
55
Atmospheric perspective
The farther the object, the more hazy with a blue tint b/c of atmosphere
56
Binocular depth cues
Cues require comparing an image as it falls on both eyes to understand its distance
57
Retinal disparity
- Difference b/w retinal images used to calculate distance b/w individual and object (far = smaller degree of retinal disparity)
- Also measured with tension of eyes (close = eyes move inward; far = eyes are straight ahead)
58
Sound
Mechanical energy that requires a medium to move through space and travels in waves of small vibrating air molecules that collide with other molecules
59
Frequency
Physical measurement of pitch in Hertz (Hz)
60
Intensity
Physical measurement of loudness of a sound measured in decibels (dB)
61
Pinna
External part of ear made of mostly cartilage that directs sound waves to eardrum
62
Tympanic membrane/eardrum
Transfers energy to the ossicles
63
Ossicles
- Malleus, incus, stapes
- Amplify vibrations and transmit signals to oval window through the stapes
- Oval window transfers vibrations to the cochlea
64
Cochlea
- Contains basilar membrane, which is a flexible tissue where auditory hair cells are
- When hair cells re displaced, they create electrochemical signals that are sent to the auditory cortex to perceive sound
65
Transduction
- Process by external sensations turn into neural firing in the brain
- Vibrations against oval window = movement in fluid in cochlea = pushes against cilia attached to hair cells = excitatory message sent to auditory nerve
66
Place theory
Suggest we understand pitch b/c of firing location on basilar membrane
67
Frequency theory
Suggests we understand pitch b/c of rate of cellular firing on basilar membrane (more rapid = higher perception of pitch)
68
Auditory cortex
Are of temporal lobe where auditory info is processed
69
Medial geniculate nucleus
Portion of thalamus that evaluates and organizes auditory info before sending it to auditory cortex
70
Tonotopic organization
Spatial organization of basilar membrane maintained through auditory pathway
71
Simple sounds (e.g. pure tones) are processed in ___ regions
Lower
72
Complex sounds (e.g. speech) are processed in ___ regions
Higher
73
Binaural cues
Auditory cues that require comparisons from both ears to understand object's location
74
Interaural time difference
Comparisons made b/w small differences in arrival time of a sound in each ear
75
Interaural level difference
Brain compares intensity differences of sounds as it arrives at each ear to understand object location (closer = slightly louder)
76
Involuntary musical imagery/earworm
Auditory experience of inability to remove song from one's consciousness
77
McGurk effect
Shows how visual info can affect auditory perception
78
Chemoreceptors
Sensory cells in nose that respond to air molecules we interpret as smell and taste
79
Smell is the only sense that DOESN'T pass through the ____
Thalamus
80
Olfactory mucosa
Tissue that contains chemoreceptros in the nose
81
Olfactory receptor neurons (ORN)
Neurons specifically responsive to odorants
82
Chemical process of smell
1) Airmorbne chemoreceptors interact w/ receptor sites in mouth and nose
2) Olfactory receptors bind to cilia of hair cells in olfactory mucosa
3) Odorants come into contact w/ olfactory receptor neurons
4) ORN send message to glomeruli in olfactory bulb in brain
83
The 5 basic tastes
Sweet, sour, bitter, salty, umami
84
Papillae and 4 types
- Papillae: Bumps on surface of tongue where tastebuds are located
- Filiform: Found on entire surface of tongue and doesn't have tastebuds
- Fungiform: On tips and side of side of tongue and look like mushrooms
- Foliate: Folds along back of tongue
- Circumvallate: Mounds along back of tongue
85
Taste pore
Location of taste-sensitive cells on tongue
86
Orbitofrontal cortex (OFC)
Region of brain that analyzes both taste and smell and gets info from "what" path
87
Bimodal neurons
Neurons that respond to more than one sense and specialize in determining sensations that occur together
88
Pressure
Physical message of touch
89
Somatosensory cortex
Where touch and motion are processed in parietal lobe
90
Mechanoreceptors and 4 types
- Receptors in skin that sense different kinds of pressure
CLOSE TO SKIN'S SURFACE:
- Merkel receptors: Fire continuously when skin is in contact w/ object
- Meissner corpuscle: Fires when skin 1st encounters stimulus and when removed
DEEPER IN SKIN
- Ruffini cylinder: Interpet stretching of skin
- Pacinian corpuscle: Vibrations and texture
91
Sensory homunculus
Visual depiction of what bodies would look like if built in proportion to representation on cortex (large hands, tongue and lips)
92
Thermoreceptors
- Receptors in skin specifically designed to detect changes in temp
- Cold fibers = increase firing to cold
- Warm fibers = increase firing to warmth
93
Pain
Adaptive response to tissue damage
94
Nociceptors
Detect pain and send signals to brain
95
Gate-control theory of pain
Painful stimuli can be blocked in spinal cord when engaged in other activities
96
Small diameter fibers (S-fibers)
Fire to damaging and painful stimuli, which activate T-cells when activated
97
Transmission cell (T-cell)
Excitation influences intensity of perception of pain
98
Large diameter fibers (L-fibers)
Send signals to brain about stimuli that's NOT PAINFUL
99
Congenital analgesia
Rare conditions where individual can't feel pain/temperature
100
Kinesthetic sense
Sense of where bodies are in space and how to move to accomplish tasks (receptors located in joints and muscles)
101
Vestibular sense
- Sense of balance
- Sensory cells in cochlea and is closely related to visual system
102
Semicircular canals
Structures in inner ear that sense changes in acceleration and rotation of head
103
Vestibular hair cells
Sensory neurons inside vestibular sacs that convert info about gravity into neural firing
104
Vestibular sacs
Structures in inner ear that respond to cues associated w/ balance and posture
105
Psychophysics
Study of how physical experience of sensations is turned into perception
106
Absolute threshold
Point of intensity required for person to detect stimulus 50% of the time
107
Signal detection
When someone detects stimulus even though there's none present
108
Difference threshold
Smallest amount of particular stimulus required for difference in magnitude to be detected
109
Just noticeable difference (JND)
Amount of stimuli required to notice difference
110
Weber's law
Ability to notice difference b/w 2 stimuli in a constant proportion of intensity/size of stimulus
