Neuropsychology Flashcards
(149 cards)
1
Q
The nervous system is divided into the _________ and _______________ nervous systems
A
Central Nervous System
Peripheral Nervous System
2
Q
Abnormal accumulation of cerebrospinal fluid in the ventricles as the result of a genetic defect, tumor traumatic injury or other factors can cause ______________
A
Hydrocephalus
3
Q
What are the symptoms exhibited by infants and young children with hydrocephalus?
A
Abnormal enlargement of the head
4
Q
What are the symptoms exhibited by adults with hydrocephalus?
A
Headaches
Loss of Balance
Impaired cognitive skills
Bladder control problem
5
Q
The brain is divided into three divisions. What are they?
A
Hindbrain
Midbrain
Forebrain
6
Q
The spinal cord carries information between the brain and peripheral nervous system. It consists of 31 segments which are further divided into 5 groups. What are the names of the 5 groups?
A
Cervical Thoracic Lumbar Sacral Coccygeal
7
Q
Damage at the cervical level results in ______________, which is also known as tetraplegia
A
Quadriplegia
8
Q
Damage at the thoracic, lumbar, sacral results in _____________
A
Paraplegia
9
Q
What is the difference between a complete and an incomplete injury?
A
Complete injury involves a total loss of sensation and voluntary movement (paralysis)
Incomplete injury may involve loss of sensation but no loss of movement or vice versa or a limited loss of sensation and/or movement
10
Q
The peripheral nervous system contains afferent nerves and efferent nerves. What is the difference between them?
A
Afferent nerves (sensory or receptor nerves) carry information from the sense organs TO the Central Nervous System (CNS) Efferent nerves (motor or effector nerves) carry information from the CNS to the muscles and glands
11
Q
The peripheral nervous system is divided into two subdivisions, what are they?
A
Somatic Nervous System
Autonomic Nervous System
12
Q
What is the somatic nervous system responsible for?
A
Controls the actions of the skeletal muscles
Voluntary movement
Relays signals from the senses of sight, hearing, smell, taste and touch
13
Q
What is the autonomic nervous system responsible for?
A
The ANS contains nerve fibers that innervate the smooth muscles, cardiac muscle, and glands. It regulates activity that is primarily involuntary, such as digestive processes, respiration, and heartbeat and changes in level of autonomic arousal are associated with changes in emotionality.
14
Q
The autonomic nervous system is divided into ____________________ and _________________
A
Sympathetic Nervous System
Parasympathetic Nervous System
15
Q
What is the sympathetic nervous system?
A
Mobilizes the body’s resources and prepares the organism for “fight-or-flight” by causing increased heart rate, pupil dilation, increased blood flow to the extremities, inhibition of digestive processes and conversion of energy stores (fat and glycogen) to glucose
16
Q
What is the parasympathetic nervous system?
A
Deactivates responses that the sympathetic nervous system activates and is active during states of relaxation. Responses include decreased heart rate, activation of digestive and elimination process, and conversion of glucose to glycogen and fat.
17
Q
Every neuron contains three main parts. What are they and their corresponding functions?
A
Cell body (soma) - Contains the neuron's nucleus, mitochondria, and other specialized structures and is responsible for most of the cell's protein synthesis Dendrites - Short fibers that project outward from the cell body. Dendrites respond to stimulation from other neurons and carry this information toward the cell body Axon - Fiber, sometimes quite long that carries information away from the cell body.
18
Q
Define Depolarization
A
Depolarization occurs when the cell receives sufficient stimulation from other cells and the electrical balance between the interior and exterior of the cell changes and the interior of the cell becomes less negative
19
Q
What is the all-or-none principle
A
Whenever the stimulation received by a neuron from adjacent cells exceeds a minimum threshold, the resulting action potential is always of the same magnitude
20
Q
The speed of conduction within a cell is affected by two factors. What are they?
A
- The larger the diameter of the axon, the greater the speed of the nerve impulse
- Some axons are covered with myelin (a fatty substance) and the thicker the myelin, the greater the speed.
21
Q
Multiple Sclerosis is due to:
A
Demyelination
22
Q
Two processes terminate synaptic transmission by removing the neurotransmitter from the synapse. Describe the two processes
A
- Reuptake - Terminal buttons take up the excess neurotransmitter and store it for future use
- Enzymatic Degradation - Occurs when enzymes in and around the synapse break down the neurotransmitter into inactive metabolites that are ultimately removed as waste
23
Q
What are neuromodulators
A
They increase or decrease the sensitivity of neurons to the effects of other neurotransmitters
24
Q
Acetylcholine
A
Cholinergic neurons
Involved in the control of voluntary movement, learning and memory, sexual behavior, and sleep and acts as an excitatory or inhibitory neurotransmitter depending on the location
Defect in ACh transmission to muscle receptors impairs voluntary movement
In the brain, ACh plays an important role in learning and memory
Degeneration of ACh receptors in the hippocampus and certain areas of the cortex contribute to the memory loss associated with normal aging and Alzheimer’s Disease
25
Name the drug that produces paralysis by blocking ACh receptors
Curare
26
Dopamine
Found in several areas of the brain including basal ganglia, limbic system and frontal lobes of the cortex.
Dopamine is involved in movement, learning, mood, and the reinforcing effects of stimulants, opiates, and nicotine.
Abnormal levels have been linked to depression, Schizophrenia, Tourette's Disorder, ADHD, Huntington's Disease and Parkinson's Disease
27
Norepinephrine
Plays a role in mood, dreaming, learning and autonomic responses. Abnormal levels contribute to a number of disorders including depression, mania and panic disorder
28
Serotonin (5-HT)
Involved in the regulation of anxiety, mood, memory, aggression, pain, sleep, appetite and sexuality. Low levels of serotonin have been linked to depression, aggression, PTSD, OCD, and Bulimia. Higher than normal levels contribute to Schizophrenia, Autistic Disorder, and decreased appetite associated with Anorexia.
29
Gamma-Amino Butyric Acid (GABA)
Main inhibitory neurotransmitter in the CNS and contributes to motor control and regulates anxiety. Abnormal level of GABA contribute to sleep, eating, anxiety, and seizure disorders, Parkinson's disease, and Huntington's disease.
Anti-anxiety medications work by increasing GABA activity
30
Glutamate
A major excitatory neurotransmitter in the CNS and is involved in long-term potentiation (LTP) - which is essential for the formation of memories. Abnormal levels contribute to anxiety disorders, mood disorders, and Schizophrenia. Overactivity at glutamate synapses ("excitotoxicity") has been linked to seizures, stroke, traumatic brain injury, Alzheimer's disease, Huntington's disease and Parkinson's disease.
31
Endorphins
Endogenous morphine act as neuromodulators and are involved in reducing feelings of pain and producing feelings of pleasure. Endorphins are believed to contribute to the "runner's high" and the pain-relieving effects of acupuncture and placebos.
32
Hypothyroidism
Caused by the undersecretion of thyroxin (released by the thyroid gland). Undersecretion of the hormone slows metabolism and causes reduced appetite, weight gain, lowered heart rate, cold intolerance, decreased sex drive, fatigue, depression, and impaired memory.
33
Hyperthyroidism
Caused by the oversecretion of thyroxin.
Hyperthyroidism is also known as "Grave's Disease".
Hyperthyroidism speeds up metabolism and cause increased appetite, weight loss, accelerated heart rate, nervousness and agitation, heat intolerance, insomnia, and decreased attention span.
34
Insulin
Released by the pancreas. It stimulates the uptake of glucose and amino acids into cells.
Undersecretion of insulin can cause diabetes mellitus, which, if left untreated with injection of insulin, leads to high blood glucose levels (hyperglycemia) and causes increased appetite with weight loss, frequent urination increased thirst, frequent infections, fatigue, apathy, sexual dysfunction, and, eventually, kidney failure, strokes, and heart attacks.
Oversecretion of insulin causes hypoglycemia which involves intense hunger, weakness, headaches, visual disturbances, palpitations, anxiety, depression, and confusion.
35
Cortisol
Cortisol is secreted by the adrenal cortex (outer layer of the adrenal gland).
Helps regulate blood glucose levels.
Undersecretion leads to Addison's disease - characterized by muscle weakness, fatigue, low blood pressure, decreased appetite and weight loss, irritability, depression, and darkening of skin pigmentation.
Oversecretion can cause Cushing's disease - characterized by obesity, hypertension, impaired concentration and memory, depression, anxiety, and decreased libido.
36
Which system is most responsible for body's fight-or-fight reaction?
Sympathetic
37
_____________ is known to be involved in the regulation of voluntary movements
Acetylcholine
38
___________ is the neurotransmitter known to play an important role in long-term potentiation (involved in the formation of memories)
Glutamate
39
Quadriplegia is most likely to be the result of damage to the spinal cord at the ___________ level
Cervical
40
Which two disorders are associated with the malfunctioning of the pancreas?
Diabetes mellitus and hypoglycemia
41
The brain is divided into three areas, what are they?
Hindbrain
Midbrain
Forebrain
42
The hindbrain and midbrain are referred to as _______________
Brainstem
43
The hindbrain contains:
Medulla Oblongata
Pons
Cerebellum
44
Describe the function of medulla oblongata
Contains vital centers that control breathing, heart rate, blood pressure, and digestion and stimulate coughing, swallowing, salivating, and other reflexive actions
45
What is the function of pons
Pons connects the two halves of the cerebellum. It is involved in relaying sensory and motor information and plays an important role in arousal, sleep, and respiration
46
What does the cerebellum control?
Cerebellum maintains balance, coordinates movements, and controls posture. Damage can produce ataxia - a condition that involves slurred speech, severe tremors, and loss of balance.
47
Reticular Activating System (RAS)
RAS is part of the reticular formation, which is a diffuse network of interconnected neurons that extends from the spinal cord to the midbrain.
The RAS regulates the sleep-wake transition and screens incoming sensory information, especially during sleep, and arouses higher centers in the brain when important information should be paid attention to.
Ex. When my puppy vomits, I will wake up to the gagging sound but otherwise, I will be asleep
48
Substantia Nigra
Substantia nigra helps control movement, and degeneration of dopamine-producing neurons in this structure contributes to Parkinson's disease.
The substantia nigra also plays a role in reward-seeking and addictive behaviors.
49
Name the subcortical structures of the Forebrain
Hypothalamus
Thalamus
Basal Ganglia
Limbic System
50
Hypothalamus
Hypothalamus exerts control over the autonomic nervous system and endocrine system via its influence on the pituitary gland.
a) Maintains the body's homeostasis by monitoring the body's internal states and controlling temperature, metabolism, and other functions.
b) Plays a role in the control of many motivated behaviors such as drinking, feeding, sex, aggression, and maternal behavior
c) Involved in the physical expression of strong emotions, especially rage, fear, and excitement
d) Contains the suprachiasmatic nucleus and the mammillary bodies
51
Suprachiasmatic Nucleus (SCN)
SCN regulates the body's circadian rhythms (biological processes that approximate a 24-hour cycle) primarily through its sensitivity to light and dark.
52
Mammillary Bodies
Mammillary bodies play a role in memory; damage to the mammillary bodies and certain areas of the thalamus (often as a result of thiamine deficiency caused by chronic alcoholism) causes Korsakoff's Syndrome - characterized by anterograde amnesia, retrograde amnesia, and confabulation (filling in memory gaps with false information while being unaware of doing so).
53
What is the function of "Thalamus"?
Thalamus acts as a central relay station by relaying incoming sensory information to the cortex for all of the senses except olfaction.
Thalamus processes information sent between different cortical regions and between the cortex and subcortical regions.
It is also involved in language, memory and motor activity
54
The basal ganglia include the ____________, __________ and the ___________
Caudate Nucleus
Globus Pallidus
Putamen
55
What is the function of Basal Ganglia?
The Basal Ganglia process and relay information necessary for the control of voluntary movement, the motor (outward) expression of emotion, and sensorimotor learning.
Abnormalities in the basal ganglia have been linked to: Tourette's Disorder, Huntington's disease, Parkinson's disease, Schizophrenia, mood disorders, obsessive-compulsive symptoms, and ADHD
56
What are the subcomponents of the Limbic system?
Amygdala
Septum
Cingulate Cortex
Hippocampus
57
Describe the function of "Amygdala"
The amygdala integrates and directs emotional reactions, attaches emotion to information it receives from the senses, and mediates defensive/aggressive behaviors.
In humans, damage may cause a lack of emotional response (especially fear) to environmental stimuli and an inability to recognize facial and vocal expressions of emotion.
58
In monkeys, bilateral lesions in the amygdala and anterior temporal lobe produce __________________
Kluver-Bucy Syndrome
59
What are the characteristics of mammals with Kluver-Bucy syndrome?
```
Reduced fear and aggression
Increased docility
Altered dietary habits
Psychic blindness - inability to recognize the significance of objects or situations
Hypersexuality
```
60
Describe the function of the Septum
The septum inhibits emotionality, and septal lesions in rats produce septal rage syndrome - characterized by hyper-emotionality and vicious behaviors.
61
Describe the function of Cingulate Cortex
Cingulate cortex plays a role in the regulation of emotional responses and pain perception.
62
Hippocampus
Involved more in memory and learning than emotion. It is responsible for memory consolidation (transfer of information from short-to long-term memory).
Bilateral destruction of the hippocampus, amygdala, and medial temporal lobes produces severe permanent anterograde amnesia.
63
What is anterograde amnesia
Inability to form new long-term memories
64
With the exception of ___________ and _________, most sensory and motor functions, the cortex displays contralateral representation.
Olfaction
| Vision
65
Lateralization of function
For over 90% of right-handers and over 60% of left-handers, the left hemisphere is responsible for written and spoken language, logical and analytical thinking. The right hemisphere is responsible for understanding spatial relationships, creative and holistic thinking, and the expression of negative emotions.
66
Each hemisphere of the cortex is divided into four lobes. Name the four lobes
Frontal
Parietal
Temporal
Occipital
67
Describe the Frontal Lobe
The frontal lobe is involved in motor behavior, expressive language, and higher-level cognitive functions. It includes the primary motor cortex, premotor cortex, Broca's area, and prefrontal cortex.
68
Primary motor cortex
The primary motor cortex is part of the pyramidal motor system and is involved in the control of voluntary movement. The pyramidal motor system consists of a pathway of neurons descending from the motor cortex to the brain stem and spinal cord and mediates fine, intricate movements and the speed and strength of movement.
Lesions in the primary motor cortex may produce contralateral motor weakness, paralysis, and/or apraxia (Disruption in the coordination of complex purposeful movements).
69
Premotor cortex
Anterior to the primary motor cortex and is active during the performance of motor actions as well as during observations of others performing familiar motor actions.
70
Broca's Area
Broca's area is located in the left frontal lobe. It is one of the primary language areas of the brain. Damage produces Broca's (expressive) aphasia - characterized by deficits in the production of written and spoken language.
People with this type of aphasia speak slowly and with great difficulty, are able to use only a few words (mostly nouns and verbs), have poorly articulated speech, have difficulty repeating phrases, may have anomia (inability to name familiar objects) and are aware of their deficits.
71
Prefrontal cortex
Essential for higher-order cognitive functions (e.g., planning, judgment, problem-solving), certain aspects of memory (e.g., working memory and prospective memory), the regulation of emotion, and motor responses.
72
Damage to _________________ causes "dysexecutive syndrome"
dorsolateral prefrontal area
73
What are the symptoms of dysexecutive syndrome?
```
Impaired problem-solving
Planning
Abstract thinking
Distractivility
Motor perseveration
Apathy
```
74
Damage to the medial frontal area may produce ___________________
Pseudodepression
75
What are the symptoms of pseudodepression?
Apathy
A lack of motivation and spontaneous movement
Reduced verbal output
76
Damage to the orbitofrontal area can cause pseudopsychopathy. What are the symptoms of this syndrome?
```
Sexual disinhibition
Coarse language
Peculiar and facetious sense of humor
Inappropriate social behavior
Lack of concern for others
```
77
Specific psychiatric disorders that have been linked to abnormal functioning of the prefrontal cortex include ___________, _____________ and ____________
Schizophrenia
Bipolar Disorders
ADHD
78
Temporal Lobe
The temporal lobe is involved in auditory processing (including receptive language) and long-term memory. It contains the auditory cortex and Wernicke's area.
79
Auditory cortex
Involved in the mediation of auditory input, and damage can produce auditory agnosia - an inability to distinguish sound, auditory hallucinations, and other auditory abnormalities.
80
Wernicke's Area
Located in the left temporal lobe and is involved in the comprehension of language. Damage may cause Wernicke's (receptive) aphasia. People with this disorder have trouble understanding language and produce fluent speech that is normal sounding in terms of rate, rhythm, and articulation but makes little or no sense. They may also display anomia and difficulties with repetition, and they are usually unaware of their deficits.
Wernicke's area is connected to Broca's area by arcuate fasciculus.
81
Conduction aphasia symptoms. What are they?
A person with conduction aphasia comprehends language and speaks fluently but has anomia and difficulty repeating what he or she has heard.
82
H.M had a bilateral _________________ to treat his severe epilepsy
Medial temporal lobectomy
83
Parietal Lobe
Parietal lobe contains somatosensory cortex, which processes somatosensory input (touch-pressure, kinesthesia, pain, and temperature) and integrates somatosensory information with other sensory information.
84
Disorders that can result from damage to the parietal lobe consist of:
Somatosensory agnosia
Apraxia
Contralateral neglect
Gerstmann's syndrome
85
Somatosensory agnosia
Somatosensory agnosia may involve tactile agnosia
(an inability to identify objects by touch)
asomatognosia (an inability to recognize one's own body parts), and/or anosognosia (an inability to recognize one's own symptoms)
86
Apraxia
The inability to execute purposeful movements despite normal motor and sensory functions. Ideomotor apraxia and constructional apraxia are two types of apraxia caused by damage to the parietal lobe.
87
Ideomotor Apraxia
People with this form of apraxia cannot carry out a request to pantomime or actually perform a particular action (e.g., blow out a candle) but may be able to perform that action spontaneously.
88
Constructional Apraxia
People with constructional apraxia cannot draw or copy simple figures or arrange blocks in a pattern.
89
Contralateral neglect
The loss of knowledge about or interest in one side of the body and things in the environment on the same side, and most often involves the right (non-dominant) parietal lobe.
90
Gerstmann's syndrome
Lesions in the left (dominant) hemisphere and involves a combination of agraphia (difficulties with writing), acalculia (difficulties with math), finger agnosia (inability to recognize and distinguish the fingers), and left-right disorientation.
91
Occipital Lobe
The occipital lobe contains the visual cortex and is involved in the processing of visual information. Total destruction of this area can produce cortical blindness, while less extensive damage may cause blind spots, persistent after-images, loss of depth perception alexia (inability to recognize printed words) or visual agnosia (inability to recognize familiar objects by sight).
92
Damage that affects the junction of the occipital, temporal, and parietal lobes may produce _________________, which is an inability to recognize familiar faces.
Prosopagnosia
93
Emotions
Emotions can be described in terms of three components:
Autonomic arousal
Feelings
Behaviors
94
What are the six identified universal emotions?
```
Happiness
Sadness
Fear
Anger
Disgust
Surprise
```
95
What did Papez (1937) propose when it comes to brain mechanisms and emotions?
Papez proposed that a neural circuit mediates both the experience and expression of emotion. The circuit includes the hippocampus, mammillary bodies, anterior thalamic nuclei of the thalamus and cingulate gyrus.
Subsequent research found that Papez's circuit is involved more in memory than emotion - especially in the formulation of declarative memories.
96
Hypothalamus
Plays an important role in the physical expression of emotion through its effects on the autonomic nervous system and pituitary gland
97
Amygdala
Involved in attaching emotional content to memory (especially fear and anxiety), mediating defensive/aggressive behaviors and recognizing fear in human facial expressions
98
Cerebral Cortex
The two hemispheres play a different role
Activation in certain areas in the left (dominant) hemisphere is associated with positive emotions. Lesions can produce a "catastrophic reaction" that involves severe depression, anxiety, and fearfulness.
Activation of area in the right (non-dominant) hemisphere is associated with negative emotions, while lesions can result in an "indifference reaction" that is characterized by apathy and indifference or, in some cases, inappropriate euphoria.
99
James-Lange Theory
Emotions occur when people experience autonomic arousal in response to environmental stimuli and then interpret that arousal as an emotional state. The theory predicts that we're afraid because we tremble and we're sad because we cry.
100
Cannon-Bard Theory
Physical arousal and the experience of emotion occur together when, in response to an environmental stimulus, the thalamus simultaneously stimulates the sympathetic nervous system ad cerebral cortex.
Cannon-Bard theory views all emotions as essentially identical in terms of physical arousal.
101
Schachter and Singer's Cognitive-Arousal Theory
Views emotion as due to a combination of physical arousal and cognitive attributions for that arousal. According to this theory, physical sensations are similar for most emotional states, and the specific emotion experienced depends the attribution for the cause of those sensations.
Schachter and Singer demonstrated that environmental cues often determine our attributions for that arousal
102
Sex hormones
Mainly estrogen and progesterone from the ovaries and mainly testosterone and other androgens from the testes.
103
The onset of puberty is initiated by increased activity in ________________________
hypothalamus-pituitary-gonadal (HPG) axis
104
What is sexual dimorphism?
There are sex-related differences in physical appearance.
105
The _____ an animal is on the phylogenetic scale, the ________ the impact of the sex hormones and the greater the impact of other factors
Higher
| Lower
106
The drop in estrogen may produce a number of physical symptoms, examples are:
```
Hot flashes
Insomnia
Mood swings
Urinary incontinence
Vaginal changes (Dryness and loss of elasticity)
Increased risk for osteoporosis
Heart disease
```
107
________________ and _____________ are two forms of therapy which have proven to alleviate many of the symptoms of menopause and reduce the risk for osteoporosis and heart disease
Estrogen Replacement Therapy (ERT)
| Hormone Replacement Therapy (HRT)
108
Men who develop _________ in adulthood have abnormally low levels of testosterone and also report a reduced sex drive.
Hypogonadism
109
Describes the five sleep stages
Stage 1 - Transitional stage between wakefulness and sleep in which fast alpha waves (awake, relaxed state) are replaced by slower theta waves. A person in stage 1 is in a drowsy state and his/her muscles relax and heart rate becomes slower.
Stage 2 - Characterized by theta waves with intermittent sleep spindles and K-complexes (bursts of faster activity and higher amplitude activity). A sleeper in stage 2 is in a state of moderately light sleep and can be easily awakened.
Stage 3 - Transitional stage between stages 2 and 4 and is marked by the appearance of large (high amplitude), slow delta waves.
Stage 4 - Characterized by large, slow delta waves. During this stage, the sleeper is breathing deeply and has a slowed heart rate and lowered blood pressure; and he/she is in a deep stage of sleep and difficult to awaken.
REM sleep - Sleeper exhibits rapid eye movements and his/her EEG pattern is similar to the patterns of stages 1 and 2. The sleeper's heart and breathing rates are similar to those of an awake person, he/she is in a deep state of sleep and is difficult to arouse.
REM sleep is also known as "paradoxical sleep"
110
Dreaming occurs in REM sleep only. True/False?
False.
Dreaming occurs during both REM and non-REM sleep, but during REM sleep, dreams are more vivid, bizarre, and emotionally laden and are more likely to be remembered when the sleeper awakens.
111
An adult sleeper passes through all five sleep stages about every ______ minutes
90
112
Pattern and Duration of sleep
During the first 6 months of life, EEG recordings show only two distinct patterns - REM and non-REM.
During the first two to three months, the sleep period begins with REM sleep.
The sequence of REM and non-REM sleep then reverses, and total sleep time, stages 3 and 4 sleep, and REM sleep all decrease in duration from childhood to adulthood, with stages 3 and 4 and REM sleep continuing to decrease throughout adulthood.
113
How many hours per day do newborns, pre-adolescents, and adults sleep?
Newborns - 16 hours
Pre-adolescents - 10 hours
Adults - 8 hours <
During infancy, REM sleep makes up about 50% of the total sleep period, while, in adulthood, it constitutes only about 20%
114
Older adults require less total sleep than younger adults. True or False?
False. Older adults do not require less total sleep than younger adults do, they often have more trouble falling asleep, awaken during the night more frequently, and experience an advanced sleep phase
115
REM Rebound
The individual spends more time than normal in REM sleep on subsequent nights after experiencing sleep deprivation.
Deprivation of stage 4 sleep produces a similar rebound effect.
116
Which brain structure(s) are linked to memory?
Hippocampus
Amygdala
Prefrontal Cortex
Temporal Lobes
117
Drugs that block the synthesis of protein or RNA during or shortly after the time of training prevents the formation of long-term (but not short-term) memories. True or False?
True
118
What is the physical stimuli for vision?
The physical stimuli for vision are light waves (electromagnetic energy) that are absorbed by photoreceptor cells in the retina of the eye.
119
Light waves entering the eye pass through, in order, _________, _______, and ______ before they are received by the retina.
1. Cornea
2. Pupil
3. Lens
120
Function of cornea
The transparent covering in front of the eye
121
Function of pupil
The opening within the iris (colored part of the eye). It opens and closes to regulate the amount of entering light, much like the diaphragm of a camera.
122
Function of lens
The lens focuses light waves on the retina, which is at the back of the eye and contains two types of photoreceptors.
123
What are the two types of photoreceptors?
Rods and cones
124
Rods
Rods are sensitive to the degree of brightness, are adapted to sensing stimuli in low levels of light, and are responsible for seeing black, white, and shades of grey.
125
Cones
Cones are specialized for detecting color, provide greater visual acuity than the rods, and function best in bright light. In humans, the cones cluster around the center of the retina, in a region called the fovea.
126
The axons of the ganglion cells form ________
Optic nerve
127
Describe the process of how visual information gets transmitted into the associated parts of the brain responsible for processing visual signals
Optic nerves join at the optic chiasm where they again split into two bundles of fibers (optic tracts). The optic tract that goes to the left hemisphere carries signals from the right visual field of both eyes, while optic tract that goes to the right hemisphere carries signals from the left visual field of both eyes. Visual signals then travel via each optic tract to the lateral geniculate nucleus in the thalamus and primary visual cortex in the occipital lobe.
128
What are the name(s) of the two theories used to explain color vision?
Young-Helmholtz trichromatic theory
| Hering's opponent-process theory
129
Describe the Young-Helmholtz Trichromatic Theory
This theory proposes that there are three types of color receptors (cones) that respond to a different primary color - red, blue, or green. This theory applies to the first level of processing in the retina.
130
Describe Hering's opponent-process theory
This theory proposes that there are three types of opponent-process cells - red-green, yellow-blue, and white-black. The opponent-process theory explains why we see afterimages (e.g., why, after staring at a green square and then looking at a blank piece of paper, we see a red image).
131
The inherited form of color blindness is usually due to an anomaly on the ___ chromosome.
X chromosome
132
Describe hair cells
Hair cells are auditory receptors. They transform mechanical vibrations to neural activity, which travels via the auditory nerve to the thalamus and auditory cortex in the temporal lobe.
133
What are the three components of sound?
Loudness
Pitch
Timbre
134
Describe loudness
Loudness (intensity) is determined by the amplitude of sound waves and is measured in decibels (db).
Normal conversation is around 60 db; truck traffic and lawn mowers are around 90db; and the pain threshold is around 120 db.
135
Describe Pitch
Pitch is determined primarily by the frequency of sound waves and is measured in terms of cycles per second, with one hertz (Hz) being equivalent to one cycle per second. In humans, the range of audible frequencies is about 20 to 20,000 Hz.
136
Describe Timbre
Timbre is the tonal quality of sound and is related to a sound wave's complexity. Timbre is what makes it possible to distinguish between two different sounds that have the same loudness and pitch (e.g., the same note played on a piano and saxophone).
137
The somesthetic senses include three types of senses, what are they?
1. Cutaneous senses
2. Kinesthetic senses
3. Vestibular senses
138
Define cutaneous senses
Senses that are sensitive to pain, temperature, and pressure
139
Define kinesthetic senses
Receptors in the muscles and joints that detect body position and movement
140
Vestibular senses
Receptors in the inner ear that are sensitive to gravity, balance, and acceleration.
141
What are some factors known to be factors affecting pain?
1. Past experience with pain
2. Expectations about pain relief
3. Presence of anxiety or depression
142
Gate-control Theory
Activation of large nerve fibers that carry information about touch, pressure, and vibration inhibits transmission of pain by small nerve fibers. Activation of the large fibers "closes the gate". Activities that close the gate include massaging or applying heat or cold to the injured area.
143
Neuropathic Pain
Caused by nervous system trauma, surgery, disease and certain drugs. Phantom limb pain is an example of neuropathic pain and sometimes occurs when a limb is amputated.
Pharmacological treatments for neuropathic pain include antidepressants, opioids, anticonvulsant drugs, and topical analgesics.
Transcutaneous nerve stimulation (TENS) help reduce phantom pain for some patients.
144
Synesthesia
"Joining senses" is an involuntary perceptual condition in which stimulation of one sensory modality spontaneously elicits a sensation in another sensory modality.
There are at least 60 different forms of synesthesia and it can involve any of the senses.
The most common form is grapheme synesthesia, in which numbers or letters are associated with specific color.
Cytowic (1993) proposed the limbic system is primarily responsible for synesthetic experiences. Other factors that may also contribute to synesthesia are sensory deprivation, drug use or brain damage
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Psychophysics
Psychophysics is the study of the relationship between the magnitude of physical stimuli and psychological (internal) sensations.
The origin of Psychophysics is traceable to Fechner whose procedures for studying this relationship involved identifying two kinds of thresholds: 1) The absolute threshold is the weakest stimulus that a person can detect. 2) The difference threshold, or "just noticeable different" (JND) is the smallest physical difference between two stimuli that is recognized as a difference.
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Absolute threshold
The absolute threshold is the intensity at which a physical stimulus is detected 50% of the time.
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Weber's Law
Predicts that the JND for any stimulus increases in size in direct proportion to the magnitude of the stimulus.
Ex. If the JND for weight is 2%, this means that if the first object weighs 50 ounces, you would not notice a difference in weight unless the second object weighs at least 51 ounces.
Equation: 50 x 0.02 = 1 (50 + 1) = 51.
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Fechner's Law
Predicts that there is a logarithmic relationship between psychological sensation and the magnitude of a physical stimulus.
The intensity of an internal sensation increases arithmetically as the intensity of the physical stimulus increases geometrically
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Steven's Power Law
Corrects the limitations of Weber's and Fechner's laws and proposes that there is an exponential relationship between psychological sensation and the magnitude of a physical stimulus, with the exponent varying for different kinds of stimuli.
