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Vision - Theories of Color Vision - Trichromatic Theory
There are three types of color receptors (cones) that are each receptive to a different primary color - red, blue, green - and all other colors are produced by variations in the activity of these three receptors
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Vision - Theories of Color Vision - Opponent-Process Theory
Three types of bipolar receptors: red-green, yellow-blue, and white-black
Some cells are excited by red and inhibited by green, and so on; and the overall pattern of stimulation of these cells produces the various colors that we perceive.
supported by the phenomenon of negative afterimages
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Vision - Color Blindness
Often the result of a genetic defect that affects one or more of the 3 types of cones, but may also be caused by a disease or injury that affects the retina, optic nerve, or other component of the visual system.
Inherited = a gene on the X chromosome --> males more prone to color blindness
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Vision - Depth perception
depends on a combination of binocular and monocular cues.
binocular cues consist of convergence and retinal (binocular) disparity and are responsible for depth perception of objects at relatively close distances
monocular cues contribute to depth perception for objects at greater distances. They include the relative size of objects, the interposition (overlap) of objects, linear and atmospheric perspective, and motion parallax (the relative movement of objects at different distances when the perceiver changes position)
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Vision - Depth perception - Retinal Disparity
referes to the fact that our two eyes see objects in the world from two different views, an, the closer and object, the greater the disparity of the two images.
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Olfaction
A chemical sense that begins with a response to airborne molecules by the olfactory receptors in the nasal cavity.
These receptors send signals through the olfactory nerve to the olfactory bulb, which acts as a relay station for olfactory information (as the thalamus does for all other sensory information). The olfactory bulb then forwards the signals to several areas of the brain.
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Cutaneous Senses
include pressure (touch), warmth, cold, and pain
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Cutaneous Senses - Dermatomes
Axons that carry information from cutaneous receptors gather together in nerves that enter the spinal cord through the dorsal roots. The area of the body that is innervated by the dorsal root of a given segment of the spinal cord is a dermatome.
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Cutaneous Senses - Pain
Unlike other senses, pain is not linked with a single type of stimulus but it elicited by several kinds of stimuli including pressure, heat, and cold.
Pain is not only a function of local sensation but may be affected by other phenomena such as intensified by depression or anxiety and reduced by distractions, deep relaxation, and hypnosis.
Pain is very susceptible to placebos
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Cutaneous Senses - Pain - Gate-Control Theory
The nervous system can process only a limited amount of sensory information at any one time. When too much information is being received, cells in the spinal cord act as a gate that blocks some incoming pain signals such as massage, applying hear or cold, and distracting mental activities.
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Cutaneous Senses - Pain - Coping Strategies
There are active and passive strategies
Active include exercise, physical therapy, using distractions, and ignoring the pain.
Passive include restricting social activities, resting in bed, taking medications to obtain relief, and wishful thinking.
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Synesthesia
A rare condition in which the stimulation of one sensory modality triggers a sensation in another sensory modality
A person might hear a color or taste a shape
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Psychophysics
The study of the relationship between physical stimulus magnitudes and their corresponding psychological sensations.
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Psychophysics - Just Noticeable Difference (JND)
The smallest increment in stimulus intensity needed to recognize the discrepancy between two stimuli.
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Psychophysics - Weber's Law
The more intense the stimulus, the greater the increase in stimulus intensity required for the increase to produce a just noticeable difference
It predicts if one gram must be added to ten grams for an increase in weight to be detected, then ten grams would have be added to 100 grams for an increase to be perceived.
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Psychophysics - Fechner's Law
States that physical stimulus changes are logarithmically related to their psychological sensations.
A person's experience of stimulus intensity increases arithmetically as the stimulus intensity increases geometrically
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According to the Young-Helmholtz ________ theory of color vision, there are three types of color receptors (cones) that are each receptive to a different primary color - red, blue, or green. In contrast, Hering's ________ theory postulates three types of bipolar receptors: red-green, yellow-blue, and white-black.
Trichromatic
opponent-process
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Because color blindness is most often due to a sex-linked recessive trait, _______ are at a higher risk for color blindness.
males
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Depth perception depends on a combination of binocular and monocular cues. __________, one of the binocular cues, refers to the fact that our two eyes see objects in the world from two different views, an, the closer an object, the great the disparity of the two images.
Retinal disparity
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With regard to olfaction, the _______ cortex is believed to be involved in the conscious perception of odors, while the _______ plays an important role in olfactory memory
orbitofrontal
amygdala
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Of the senses, ________ is the only one that is not linked to a single type of stimulus
pain
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According to ________ theory, the perception of pain can be blocked by special cells in the spinal cord.
gate-control
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Although the results of studies comparing active and passive strategies for coping with pain are inconsistent, they generally confirm that ________ strategies are associated with lower levels of reported pain and greater improvement in psychological and physical functioning.
active
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_________ is a rare condition in which the stimulation of one sensory modality triggers a sensation in another sensory modality
Synesthesia
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Psychophysics is the study of relationships between physical stimulus and the corresponding psychological sensations. According to _________ Law, the more intense the stimulus, the greater the increase in intensity needed to produce a just noticeable difference. Fechner's Law purposes that phsycial stimulus changes are _________ related to their psychological sensations; and, according to _________ Law, sensation is an exponential function of stimulus intensity.
Weber's
logarithmically
Stevens's Power
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An inherited form of complete color blindness caused by a lack of functioning in the cone cells is known as ___________.
A.cerebral achromatopsia
B.color blindness
C.congenital achromatopsia
D.occipitotemporal blindness
C
Congenital achromatopsia (or achromatopsia) is color blindness due to malfunctioning cells. This condition is inherited.
Answer A: Cerebral (or central) achromatopsia is complete color blindness due to a lesion in the brain.
Answer B: This answer is too general because the question is asking about a specific type of color blindness.
Answer D: The brain lesion that causes cerebral achromatopsia is usually in the occipitotemporal region but this question is describing congenital achromatopsia.
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Gate control theory is useful for:
A.Identifying methods for controlling pain
B.Explaining color vision
C.Understanding why it is difficult to acquire a second language after a certain developmental age
D.Understanding the mechanisms underlying depth perception
A
According to gate control theory, stimulation of certain nerves in the skin or brain can inhibit the transmission of pain messages in other nerves.
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A woman is exhibiting synesthesia when she says that she:
A.Cannot perceive pain
B.Cannot identify people by their faces
C.Experiences different musical notes as different colors
D.Experiences memory loss for new information
C
Synesthesia is when the simulation of one sensory modality triggers a sensation in another modality. Experiencing sounds as colors is one type of synesthesia. Another example would be experiencing a certain smell connected to specific words or letters.
Answer A: This is known as analgesia or if from birth, congenital analgesia.
Answer B: An inability to recognize people's faces is called prosopagnosia.
Answer D: This is describing anterograde amnesia.
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Which of these sensory systems does not have a connection through the thalamus?
A.Touch
B.Vision
C.Audition
D.Olfaction
D
Of all the senses, olfaction (sense of smell) is the only one that is not part of the thalamic relay system.
Answers A, B, and C: The senses of touch, sight, sound, and taste are part of the thalamic relay system of information. The thalamus is like a "relay station," providing messages of these senses to the appropriate parts of the brain.
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Which theory best describes sensation as an exponential function of stimulus intensity?
A.Steven's Power Law
B.Weber's Law
C.Fechner's Law
D.Thorndike's Law of Effect
A
Steven's Power Law expanded on Fechner's Law and Weber's Law. It led to a description of sensation as an exponential function of stimulus intensity.
Answer B: According to Weber's Law, the more intense a stimulus, the greater the need for an increase in stimulus intensity to produce a noticeable difference.
Answer C: Fechner's Law determines the relationship between the magnitude of a stimulus and the magnitude of the associated sensation.
Answer D: Thorndike's Law of Effect states that any behavior followed by a pleasant consequence is likely to be repeated and any behavior followed by an unpleasant consequence is likely to be stopped.
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Retinal disparity helps to explain:
A.The use of both eyes to perceive depth or distance
B.The use of one eye to distinguish an object from its background
C.The difference between the right and left visual fields
D.The difference between near and far sightedness
A
Retinal disparity is also known as binocular disparity and refers to the fact that our two eyes see the world from two different positions. Retinal disparity contributes to depth perception for objects at relatively close distances (within about 18 to 20 feet), while other cues such as shadows and the relative motion of objects contribute to depth perception at larger distances.
Answers B, C, and D: These answers describe different aspects of vision but Answer A is the best description of retinal disparity.
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