Sensation and Perception Flashcards
1
Q
What did Jonathan I. develop after sustaining brain injury?
A
Cerebral achromatopsia
2
Q
What is cerebral achromatopsia?
A
Loss of colour vision
3
Q
What is sensation?
A
Process by which a stimulated receptor creates a pattern of neural messages that represent the stimulus in the brain, giving rise to our initial experience of the stimulus
4
Q
What is perception?
A
A mental process that elaborates and assigns meaning to the incoming sensory patterns
5
Q
Sensation is to perception as ________ is to _________
A
Stimulation; recognition
6
Q
What is a sensory receptor?
A
A specialised neuron that detects sensory energy in the outside world
7
Q
What is transduction?
A
The sensory process that converts information carried by a physical stimulus (such as light or sound waves) into the form of neural messages/impulses
8
Q
Nerve impulses that carry information travel along _______, usually by way of the _______, to specialised processing areas in the brain
A
Sensory pathways; thalamus
9
Q
What is absolute threshold?
A
The point at which a person can detect a stimulus 50% of the time it is presented
10
Q
The absolute threshold for vision is defined as the ability to detect _________ located _________ on a clear night
A
a candle flame; 30 miles away (~48km)
11
Q
The absolute threshold for human hearing is the _______ from ________ under very quiet conditions
A
tick of a watch; 20 feet (~6m)
12
Q
The absolute threshold for smell is one drop of ________ diffused throughout a ________
A
perfume; three-room apartment
13
Q
The absolute threshold for taste is _________ in _________
A
one teaspoon of sugar; 2 gallons of water (~7.5l)
14
Q
The absolute threshold for touch is a ________ falling on the ________ from ________ above
A
bee’s wing; cheek; 1 centimetre
15
Q
What is the difference threshold?
A
Degree of change in a stimulus level that is required in order for a person to detect a change 50% of the time
16
Q
What is another name for difference threshold?
A
Just noticeable difference (JND)
17
Q
What is another name for just noticeable difference (JND)?
A
Difference threshold
18
Q
What is Weber’s law?
A
Weber’s law states that the size of the JND is proportional to the intensity of the stimulus
aka The amount of change needed to detect a JND increases as the intensity of the initial stimulus increases
19
Q
What is signal detection theory?
A
The signal detection theory explains how we detect signals consisting of stimulation affecting our eyes, ears, nose, skin and other sense organs
20
Q
According to signal detection theory, sensation depends on the: (3 things)
A
characteristics of the stimulus,
background stimulation,
detector
21
Q
Signal detection theory suggests that differences in absolute thresholds between different people reflect ________
A
human judgment
22
Q
What is sensory adaptation?
A
The loss of responsiveness in receptor cells due to constant stimulation
23
Q
The sensory pathways carry information from _________ to _________
A
sense organs; the brain
24
Q
Why do sensory psychologists use the standard of the amount of stimulation that your sensory system can detect about half the time for identifying the absolute threshold?
A
The amount of stimulation that we can detect is not fixed
It varies depending on ever-changing factors such as our level of arousal, distractions, fatigue, and motivation
25
Use the concept of transduction to explain why the brain never directly senses the outside world
The senses transduce stimulation from the external world into the form of neural impulses
which is the only form of information that the brain can use
Therefore, the brain does not deal directly with light, sound, odors, and other stimuli but only with information that has been changed (transduced) into neural messages
26
Which is the most complex and highly developed sense for humans?
Sight
27
What is the retina?
The light-sensitive layer of cells at the back of the eye
28
Each retina of the eye has about ______ million rods
125 million rods
29
What are photoreceptors?
Light-sensitive cells (neurons) in the retina that convert light energy to neural impulses
30
What are the two types of photoreceptors?
Rods and cones
31
Which component of the eye contains the visual receptors?
Retina
32
Visual transduction occurs within the
Retina
33
What are rods?
Photoreceptors in the retina that are especially sensitive to dim light but not to colours.
(They are rod-shaped)
34
What are cones?
Photoreceptors in the retina that are especially sensitive to colours but not to dim light
(they are cone-shaped)
35
Are rods or cones responsible for helping us perceive colours?
Cones
C for Colour!
36
What sort of stimulation do the cones detect?
The cones give us high-resolution color vision in relatively bright light and sharp images
37
Are rods or cones responsible for vision in low-level situations?
Rods
D in roDs stand for Dark
38
What sort of stimulation do the rods detect?
The rods are better than the cones for detecting objects in dim light
39
Where are cones located?
They are concentrated in the very centre of the retina, in a small region called the fovea
Funfact the fovea also gives us our sharpest vision
40
What is the fovea?
The tiny area of sharpest vision in the retina
41
What is the correct order in which light activates the visual cells of the retina?
Rod and cone cells (photoreceptors) -> bipolar cells -> ganglion cells
42
Bundles of axons from ganglion cells make up the _________
optic nerve
43
What is the optic nerve?
Bundle of neurons that carries visual information from the retina to the brain
44
The ________ refers to the region of the eye at where the ________ exit the eye
blind spot; optic nerve
*there are no photoreceptors there! any stimulus that falls on the blind spot cannot be seen
45
What is the visual cortex?
A special brain area that creates visual images from the information imported from the eyes through the optic nerve
46
The aspect of colour that corresponds to names such as red, green and blue is _________
hue
47
The psychological sensations of vision relating to
wavelength: ________
intensity (amplitude): _________
colour; brightness
48
The physical stimulation of vision relating to
colour: __________
brightness: __________
wavelength; intensity/amplitude
49
The visible spectrum refers to
the portion of the whole spectrum of light that is visible to the human eye
50
Range of wavelength of visible light is?
400nm (blue) to 700nm (red)
51
Humans can typically discriminate amongst _________ hues
5 million
52
What is the trichromatic theory?
The idea that the eye contains three different types of cones (receptors) sensitive to light in the red, green and blue wavelengths
and that is how colours are sensed
53
What is the trichromatic theory sometimes called?
Young-Helmholtz theory
54
What is the opponent-process theory?
The idea that cells in the visual system process colours in complementary pairs
such as red/green or yellow/blue
55
The trichromatic and opponent-process theories of colour vision are not in conflict because each corresponds to _________.
What do they correspond to?
a different portion of the spectrum
trichromatic: concerns what happens when light hits the cones in the retina
opponent-process: concerns neural signals in the bipolar cells and on their way to the brain
56
What is an afterimage?
A sensation that lingers after the stimulus is removed
Most visual afterimages are negative afterimages, which appear in reversed colours
57
_____ have more problems with colour vision
Men
due to the sex-linked nature of most forms of colour blindness
58
The psychological sensations of hearing relating to
frequency (wavelength): ________
intensity (amplitude): _________
complexity: _________
pitch; volume; timbre
59
The physical stimulation of hearing relating to
pitch: __________
volume: __________
timbre: __________
wavelength; intensity/amplitude; complexity
60
Which is a characteristic of both light waves and sound waves?
Wavelength
61
A sound wave generated in outer space will travel at the rate of _________
0 feet per second
sound waves cannot be formed in outer space
62
Snapping your fingers causes the surrounding air to _________
vibrate
63
In terms of sound waves, frequency refers to the
number of vibrations the wave completes in a given time
64
The eardrum is also called the
tympanic membrane
65
The outer ear is also called the
pinna
66
The tiny bones in the middle ear consist of the
hammer, anvil, stirrup
67
The pinna is the
outer ear
68
The tympanic membrane is the
eardrum
69
The hammer, anvil and stirrup form the
tiny bones in the middle ear
70
What is the cochlea?
The primary organ of hearing
A coiled tube in the inner ear, where sound waves are transduced into nerve messages
71
The hammer, anvil and stirrup transmit sound waves from the _________ to the __________
outer ear; cochlea
72
What happens in the cochlea? (in terms of wave conversion)
Airwaves are converted to fluid waves
73
What is the basilar membrane?
What is its function?
A thin strip of hairy tissue sensitive to vibrations in the cochlea
The basilar membrane contains hair cells connected to neurons
When a sound wave causes the hair cells to vibrate, the associated neurons become excited
Result, the sound waves are converted (transduced) into nerve messages
74
Fluid located in the cochlea is set in motion and causes vibration in the _______
basilar membrane
75
Sounds are converted into action potentials within the ___________ and then transmitted to the ____________ in the ____________
basilar membrane; auditory cortex; temporal lobes
76
The ________ are the auditory receptors where sound waves finally become neural impulses
hair cells
77
How do we hear sound waves? (4 steps)
1. Airborne sound waves are relayed to the inner ear
Vibrating waves of air enter the outer ear, move through the ear canal to the eardrum. This tightly stretched sheet of tissue transmits the vibration to the hammer, anvil and stirrup. These bones pass the vibrations on to the cochlea in the inner ear
2. The cochlea focuses the vibrations on the basilar membrane
In the cochlea, the airborne sound becomes "seaborne". As the stirrup vibrates against the oval window at the base of the cochlea, the vibrations set the fluid into wave motion, causing vibration in the basilar membrane
3. The basilar membrane converts the vibrations into neural messages
The swaying of tiny hair cells on the vibrating basilar membrane stimulates sensory nerve endings connected to the hair cells. The excited neurons transform the mechanical vibrations of the basilar membrane into neural activity
4. The neural messages travel to the auditory cortex in the brain
Neural signals leave the cochlea in a bundle of neurons called the auditory nerve. The neurons from the two ears meet in the brain stem, which passes the auditory information to both sides of the brain. Ultimately, the signals arrive in the auditory cortex in the temporal lobes for higher-order processing
78
Humans can hear a range between _______ to _______Hz
20; 20,000
79
Place theory argues that sounds of __________ induce vibration in different areas of the ___________
different frequencies; basilar membrane
80
What is place theory?
Place theory of pitch suggests that pitch is determined by the specific location where hair cells are stimulated
Accounts for our ability to hear high tones above 1000Hz
81
What accounts for our ability to hear high tones above 1000Hz?
Place theory of pitch
82
Frequency theory alone would best describe how the basilar membrane deals with frequencies below _________
5000Hz
83
What accounts for our ability to hear below 5000Hz?
Frequency theory
84
What is frequency theory?
Neurons on the basilar membrane respond with different firing rates to different sound wave frequencies
85
What is special about the range of 1000 to 5000Hz?
This interval spans the upper frequency range of human speech
Is crucial for discriminating high-pitched sounds that distinguish consonants like p, s, t
The auditory canal is specially shaped to amplify sounds within this speech range
86
What can cause hearing loss? (3 things)
1. Aging
2. Diseases that attack auditory nerve
3. Exposure to loud noises that damage the hair cells in the cochlea
87
The _______ sense allows us to orient our body with respect to gravity
Vestibular
88
What is the function of the vestibular sense?
The body position sense that orients us with respect to gravity
It also tells us when we are moving or how our motion is changing
89
What are the receptors for our vestibular sense? What is their function? Where do they connect to?
Tiny hairs in the semicircular canals of the inner ear
They respond to our movements by detecting corresponding movements in the fluid of the semicircular canal
Allows us to maintain our balance and tell our posture
Connect to parietal lobes
90
The ______ sense controls knowledge of the position of your limbs and keeps track of body parts relative to each other
Kinesthetic
91
What is the kinesthetic sense?
The body position and movement sense that keeps track of body parts relative to each other
92
What are the receptors for our kinesthetic sense?
Where do they connect to?
Kinesthetic receptors in joints, muscles and tendons
They connect to the parietal lobes
93
Sense of smell is also known as
olfaction
94
Sense of smell is adaptive in that (4 functions)
1. aids in the location of food
2. allows us to detect decaying food
3. signals sexual receptivity in some mammals
4. can mark the boundaries of a territory
95
What are pheromones?
chemical signals released by organisms to communicate with other members of their species
often used by animals as sexual attractants
96
Sense of taste is also known as
gustation
97
What are the five primary qualities/dimensions of taste?
Sweet, sour, bitter, salty, umami
98
Structure of taste receptors?
On the tongue, there are small mucous-membrane projections "bumps" called papillae
There are taste buds in every papillae
And there are taste receptors/gustatory cells in the taste buds
99
What can produce a loss of taste reactivity? (6 things)
1. Aging
2. Reduced density of papillae on the tongue
3. Alcohol
4. Smoking
5. Acids
6. Hot foods
3-6 damage our taste receptors
but they can be replaced :D
100
Which system boasts the most resistance to permanent damage?
Taste
101
What are supertasters?
Individuals with relatively high density of papillae on the tongue (most taste buds)
and hence are more sensitive to taste than others
102
Sensory information related to the skin senses is processed within the ___________
somatosensory cortex
103
What are skin senses?
Sensory systems for processing touch, warmth, cold, texture and pain
104
We are ____ times more accurate in sensing stimulation on our fingertips than stimulation on our backs
10
Due to more receptors on our fingertips than our backs
Other places with more receptors are face, tongue, hands
105
What are the important functions of touch? (3 functions)
Through touch, we communicate our desire to give or receive comfort, support and love
Touch also serves as a primary stimulus for sexual arousal in humans
It is essential for healthy mental and physical (motor) development
106
What is synesthesia?
The mixing of sensations across sensory modalities, as in tasting shapes or seeing colours associated with numbers
107
What might be the cause of synesthesia?
The cortical area called the TPO, lying at the junction of the temporal, parietal, and occipital lobes, simultaneously processes information coming from many pathways
Synesthetes have more neural connections among the TPO lobes
108
What are pain receptors called?
Nociceptors
109
What do pain receptors do?
Specialize nerve cells, called nociceptors, sense painful stimuli and send their unpleasant messages to the central nervous system
Different nociceptors are sensitive to different stimuli (heat/pressure/chemical trauma/tissue injury/itching)
110
What are the two distinct regions that have primary roles in processing incoming pain messages?
1. A pathway terminating in the parietal lobe - registers location, intensity and sharpness or dullness of pain
2. A group of structures deep in the frontal cortex and the limbic system - registers how unpleasant the painful sensation is
111
What is the phantom limb condition?
When the amputee feels sensations, sometimes painful ones, that seem to come from the missing body part
112
How does the phantom limb condition work?
Phantom limb sensations arise in the brain, perhaps the result of the brain generating sensation when none comes from the missing limb
113
What does the phenomenon of phantom limbs teach us?
Understanding pain requires understanding not only painful sensations but also mechanisms in the brain that both process and inhibit pain
114
What is the gate-control theory of pain?
The idea that pain signals must pass through a neural "gate" in the spinal cord.
The "gate" involves special interneurons that can open or close the pain pathway running up the spinal cord towards the brain
Under some circumstances, closing the "gate" can interfere with the transmission of pain messages in the spinal pathway and block incoming pain signals
115
What can close the "gate" mentioned in gate-control theory? (3 things)
1. Messages from nonpain nerve fibers (eg those involved in touch)
2. Messages from the brain - opiate drugs like morphine initiate a cascade of inhibitory messages that travel downward to block incoming pain messages
3. Hypnosis
116
Psychological aspects of pain perception can influence the release of neurotransmitters called _________ which are the body's natural version of morphine
endorphins
117
The capacity of a placebo treatment to reduce pain perception is due to ____________
release of endorphins in the brain
118
What is the main function of pain?
It serves as an essential defense signal: it warns us of potential harm,
and helps us to survive in hostile environments
and to get treatment for sickness and injury
119
How does pain become a disease in itself?
Neurons in the pain pathways become hypersensitive, amplifying normal sensory stimulation into pain messages
Chronic pain may sometimes arise from genes that get "turned on" in nerve-damaged tissue
120
What is the main function of morphine?
Morphine suppress pain messages in the spinal cord and the brain
121
What is the main function of aspirin?
Aspirin interferes with a chemical signal produced by damaged tissue
122
What are unwanted side effects of analgesics (pain killing drugs)? (2 points)
1. Digestive tract or liver damage
2. Addiction
123
What is a placebo?
A substance that appears to be a drug but is not
Often referred to as a "sugar pill" because they might contain only sugar rather than a real drug
124
What are 3 ways to control pain using psychological techniques?
1. Hypnosis
2. Relaxation
3. Thought-distraction procedures
4. Placebos
125
What is the placebo effect?
A response to a placebo (a fake drug) caused by the belief that it is a real drug
126
How do placebos work?
The expectation of pain relief (by taking a "real drug") is enough to cause the brain to release painkilling endorphins
127
Individuals who respond to placebos report that their pain increases when they take the ______-blocking drug _______
endorphin; naltrexone
128
__________ can lessen the psychological pain of social rejection
Acetaminophen
129
Acetaminophen can lessen the psychological pain of _________
social rejection
130
What do all of the following senses have in common: vision, hearing, taste, smell, hearing, pain, equilibrium, and body position?
Each of these senses transduces physical stimulation into neural activity
and each responds more to change than to constant stimulation
131
Explain why different senses give us different sensations
The different sensations occur because the sensory information is processed by different parts of the brain
132
A percept consists of _________ in combination with _________
sensation; associated meaning
meaning: concepts, memories of events, emotions, motives
133
What are the two visual pathways that help us identify objects and locate them in space?
What pathway: determines what objects are
Flows mainly to the temporal lobe, extracts information about an object's colour and shape
Where pathway: determines an object's location
Projects to the parietal lobe
134
What is the function of the what and where pathways?
To help us identify objects and locate them in space
135
What is blindsight?
The ability to locate objects despite damage to the visual system making it impossible for a person consciously to see and identify objects
Is thought to involve unconscious visual processing in the where pathway
136
What are feature detectors?
Cells in the cortex that specialise in extracting certain features of a stimulus, like length, slant, colour, boundary, location, and movement
137
What is the binding problem?
The fact that we do not know how the brain combines multiple sensory features it detects into a single percept
138
What are the two complementary processes involved in forming a percept?
1. Top-down processing
2. Bottom-up processing
139
What happens in top-down processing?
Our goals, past experience, knowledge, expectations, memory, motivations, or cultural background guide our perceptions of objects or events
140
What is another name for top-down processing?
Conceptually-driven processing
141
What happens in bottom-up processing?
Perceptual analysis emphasises characteristics of the stimulus, rather than our concepts and expectations, which influence our perceptions
142
What is another name for bottom-up processing?
Stimulus-driven processing
143
What are the types of percetual constancy? (3)
1. Size constancy
2. Colour and brightness constancy
3. Shape constancy
144
What is perceptual constancy?
The ability to recognise the same object as remaining "constant" under different conditions, such as changes in illumination, distance, or location
145
What is size constancy?
Tendency to interpret an object as always being the same physical dimensions, regardless of its distance from the viewer
Serves as a strong cue for depth perception
146
What is shape constancy?
Tendency to interpret an object as always being the same shape from different angles
147
What is colour and brightness constancy?
Ability to see an object as essentially unchanged under different lighting conditions
148
What is inattentional blindness?
A failure to notice changes occuring in one's visual field, apparently caused by narrowing the focus of one's attention
149
What is change blindness?
A perceptual failure to notice that a visual scene has changed from the way it had appeared previously
It requires comparing a current scene to one from the past, stored in memory
150
What is an illusion?
It is when your mind deceives you by interpreting a stimulus pattern incorrectly
Usually, other people observing the same stimulus are also deceived
(If they are not, it might be a hallucination)
151
How does the black-and-white Hermann grid illusion work?
The firing of certain cells that are sensitive to light-dark boundaries inhibits the activity of adjacent cells that would otherwise detect the white grid lines
This inhibiting process makes you sense darker regions - the grayish areas - at the white intersections just outside your focus
152
What are ambiguous figures?
Images that can be interpreted in more than one way
There is no "right" way to see an ambiguous figure
153
What are 2 famous examples of ambiguous figures?
1. vase/faces figures
2. Necker cube
154
Your ability to view and interpret an ambiguous figure in two different ways is a result of
alternating perceptual control between the left and right hemispheres
155
What did we learn about the Muller-Lyer illusion through different cultures?
It is learned
156
What are 2 influential theories that explain fundamental perceptual principles (how we form our perceptions)?
1. Gestalt theory
2. Learning-based theory
157
What is Gestalt theory?
Gestalt theory suggests that our brains are innately "wired" to perceive stimuli in specific ways
Is a "nature" approach
158
What is learning-based inference?
Learning-based inference emphasises learned influences on perception, including the power of expectations, context and culture
Is a "nurture" approach
159
Learning-based interference is to nurture as _________ is to nature
Gestalt theory
160
Gestalt theory is to nature as _______________ is to nurture
Learning-based inference
161
What is the perspective of Gestalt psychology?
From the raw material of stimulation, the brain forms a perceptual whole that is more than the mere sum of its sensory parts
aka we should focus on the "whole" rather than its individual parts
162
What are the 5 Gestalt principles?
1. Figure-ground
2. Closure
3. Law of proximity
4. Continuity
163
What is the Gestalt principle of figure-ground?
What do figure and ground mean?
It distinguishes patterns (figure) from their backgrounds (ground)
Figure: part of a pattern that commands attention. stands out against the ground
Ground: part of a pattern that does not common attention; the background
164
What is the Gestalt principle of closure?
The tendency to fill in gaps in figures and to see incomplete figures as complete
165
What are the laws of perceptual grouping?
What do the laws suggest about our brains?
the Gestalt principles of similarity, proximity, continuity and common fate
They suggest how our brains prefer to group stimulus elements together to form a percept
166
Who formulated the set of laws of perceptual grouping?
Wertheimer
167
What is the Gestalt principle of law of similarity?
Tendency to group similar objects together in our perceptions
Similar: look/sound/feel
Eg team colours
168
What is the Gestalt principle of law of proximity?
The tendency to group objects together when they are near each other
169
What is the Gestalt principle of law of continuity?
That we prefer perceptions of connected and continuous figures to disconnected and disjointed ones
(also operates in the realm of social perception, assuming that personality does not change)
170
What is the Gestalt principle of law of common fate
Tendency to group similar objects together that share a common motion or destination
171
What is the law of Pragnanz?
The most general Gestalt priniciple, which states that the simplest organisation, requiring the least cognitive effort, will emerge as the figure
Tendency to perceive things in the simplest manner possible
172
What does "Pragnanz" mean?
Meaningfulness
173
What is another name for the law of Pragnanz?
Minimum principle of perception
174
Who founded the theory of learning-based inference?
Hermann von Helmholtz
175
Hermann von Helmholtz was a proponent of which perceptual theory?
Learning-based inference
176
The learning perspective suggests that the most important factors in determining our ability to identify a percept are: (3)
Context, expectation and perceptual sets
177
What is a perceptual set?
A readiness to detect a particular stimulus in a given context
178
Our sense of depth or distance relies on cues that can be grouped into 2 categories:
1. Binocular cues
2. Monocular cues
179
What are binocular cues?
Information taken in by both eyes that aids in depth perception
Including binocular convergence and retinal disparity
180
What is binocular convergence?
It suggests how the lines of vision from each eye converge at different angles on objects at different distances
181
What is retinal disparity?
Seeing greater disparity when looking at nearby objects than we do when viewing distant objects due to the difference in perspectives of the two eyes
182
What are monocular cues?
Information about depth that relies on the input of just one eye
Includes relative size, linear perspective, light and shadow, interposition, relative motion and atmospheric perspective
183
What is relative size (monocular cue)?
If two objects that are assumed to be the same size cast different-sized images on the retina, observers usually judge them to lie at different distances
184
What is linear perspective (monocular cue)?
Apparent convergence of parallel lines
185
What is light and shadow (monocular cue)?
Lighter-coloured objects seem closer to us and darker objects seem further away
186
What is relative motion (monocular cue)?
As you move, objects nearer to you appear to move through your field of vision faster and more distant objects appear to move through your field of vision slower
187
What is atmospheric perspective (monocular cue)?
Haze or fog makes objects in the distance look fuzzy, less distinct, or invisible
188
What is interposition (monocular cue)?
Assumption that an object that appears to be blocking part of another object is in front of the second object and is closer to the viewer
Assumption that closer objects will cut off our vision of more distant objects behind them
189
What do perceptual constancies do for us?
Perceptual constancies allow us to identify and track objects under a variety of conditions, such as changes in illumination or perspective
190
Why does the Ponzo illusion illustrate the idea that perception is not an exact internal copy of the world?
The Ponzo illusion involves the most extensive perceptual interpretation
191
Vibrating air molecules enter the ears at the _________
pinna (outer ear)
192
Where are the olfactory bulbs located?
Just below the frontal lobes
193
Explain the major principles of Gestalt psychology (3 features)
1. This perspective believes that the brain is designed to seek patterns
2. The theory claims that much of this is innate
3. The theory claims that "the whole is more than the sum of its individual parts"
194
Contrast the two major views of colour vision theory
Trichromatic theory:
- 3 classes of photoreceptors detect colour, with each colour representing a mixture of activation of the receptors
- cannot account for negative colour afterimages
Opponent-process theory:
- red light may activate a cell in the visual system, while green light inhibits that cell
- can account for negative colour images
