Flashcards in Neuropsych Deck (177)
What is the pattern of sleep duration over the life span?
First 6 mo.. REM and non REM. during the first 2 or 3 mo..starts with REM.. This reverses.
Total sleep time, stages 3 and 4 sleep, and REM sleep decrease from childhood to adulthood.
Stages 3 and 4; REM continue to decrease through adulthood
Sleep time...newborns...16 hrs
....preadolescents ...10 hrs
Adults...8 or less
Infancy..REM is 50 percent
Adult..REM is 20 percent
Older adults not require total less sleepy than young adults..more trouble falling asleep, wake in nite, experience advanced sleep phase (shift in timing of sleep involves going to sleep earlier and waking earlier)
What brain structures are involved in memory?
Hippocampus is involved in memory consolidation
Amygdala is involved in emotional memories
Prefrontal cortex...working and prospective memory
Temporal lobes...stores long term declarative memories.
Long term potentiation...first seen in glutamate receptors of hippocampus and later the brain. Hi frequency stimulation of neurons increases sensitivity and structure of dendrites...memories form
Protein synthesis...new ones for LTM and modifyjng pre existing proteins for STM. Administering a drug that blocks protein synthesis or RNA (needed for synthesis) prevents formation of memories.
Neural foundations for memory.
Papez's circuit was identified as a neural pathway involved in:
A. Fight or flight
B. experience and expression of emotion
C. Onset of puberty
D. Coordination of movement in rt and left sides of body
B. proposed expression of emotion governed by hypothalamus
Experience of emotion is result of interactions among hypothalamus and other structures.
What are the theories of color vision?
Trichromatic theory by young helmholtz...3 types of cones that respond to red, blue, green. Applies to the first level of processing in the retina.
Herings opponent process theory says 3 types of opponent process cells (red-green; blue- yellow; black-white). Applies to the second level of processing that occurs as visual signals pass from retina to visual cortex.
What is the auditory pathway?
Ear to auditory canal to eardrum to membrane that vibrates in response to sound waves. Vibs picked up and amplified by ossicles and transmitted to the oval window. Movement here exerts pressure on liquid in cochlea and produces movement in hair cells (auditory receptors). Vibs made to neural activity via auditory nerve is to thalamus, and auditory cortex.
What are the components of sound?
Loudness...amplitude if waves. Db
Decibels. Convo is 60
Pitch frequency of sound waves. Measured cycles per sec. Humans range is 20 to 20,000 hertz
Timbre to tone quality and sounds waves complexity. Makes it possible to distinguish between 2 sounds have same loudness and pitch.
What is pain effected by?
Not caused by a single stimuli but by several types of stimuli like heat; pain, pressure,....
Sensitivity is affected by past pain experience, presence of anxiety, or depression .
For some, more previous experience , greater sensitivity.
What is the gate control theory?
Activation of large myelinated nerve fibers that carry info about touch, pressure, and vibration inhibits transmission of pain by small un myelinated nerve fibers.
Close the gate with massage, heat, cold, info traveling from brain (distraction reduces pain).
What is neuropathic pain?
Caused by nervous system trauma, surgery, disease, and drugs. Phantom limb pain example. Cause unknown...think due to damage to neurons in CNS or PNS. Psych factors don't cause it may play role in course and severity.
Drug tx..antidepressants (esp tricyclics like amitryptyline, doxepin, imipramine and SRNI venlafaxine)., opioids, anticonvulsants, topical analgesics.
Some evidence TENS reduces...transcutaneous nerve stimulation.
What is synesthesia?
Involuntary perceptual condition in which stimulation of one sensory modality elicits a sensation in another.
Involve any of the senses
Most common is grapheme synesthesia in which numbers or letters are associated w specific colors.
May be due to limbic system, increased connectivity between associated regions, mostly think genetic reasons.
May be due to sensory deprivation, drug use, or brain damage.
What is psychophysics?
What are the two thresholds for studying it?
Relationship between the magnitude of physical stimuli and psychological stimulation.
1. Absolute threshold...weakest stimulus person can detect. Defined as intensity at which a physical stimuli is detected 50 percent of the time.
2. Just noticeable difference... Smallest physical difference between two stimuli that is recognized as a difference. This varies due to stimulus type and initial intensity.
What are the psychophysical laws?
Webers law...jnd increases in size proportionate to magnitude of the stimulus.
Fechners law...logarithmic relationship between psych sensation and magnitude of physical stimulus. Internal stimulus increases arthmetically and physical increase geometrically.
More accurate for extreme.
Not work for all types of stimuli.
Stevens power law..corrects others
Exponential relationship between psych sensation and physical magnitude. Exponent varies by stimuli. Research using method of magnitude estimation (students assigned numbers to stimul)
Whose law says there is a logorithmic relationship between psych sensation and intensity of physical stimulus.
Which transforms sound waves into neural signals?
B. hair cells
D. Bipolar cells
Stare at red square shift to rt and see image of ----- square. This supports what?
A. Green, opponent
B. green, trichromatic
C. Blue, opponent
D. Blue, trichromatic
Gate control theory explains:
A. How neurotransmitters reduce the likelihood that an action potential will occur.
B. how certain stimuli can block or modify pain perception
C. Why the magnitude of just noticeable difference differs for different stimuli.
D. How sounds vary in terms if timbre.
Which drug is useful for alleviating neuropathic pain?
Joe sees the number 1 as a green number, 2 as purple, and 3 as red. This condition is:
A. Getstmanns syndrome
What are the structural brain imaging techniques? What do structural techniques do?
Structural techniques identify structural changes due to blood clots, tumors, strokes, degenerative disease, inflammation, infection.
Both..cross sections of brain;
Sensitive to tissue density
CT computerized axis tomography
Don't have to be motionless for a long period of time.
MRI magnetic resonance imagery
Uses magnetic field & radio waves
What are the functional imaging techniques?
Functional imaging gives info about brain structure and activity
PET scan, SPECT, functional MRI
PET..small amounts if radioactive material to see neural activity by measuring blood flow, glucose metabolism, or oxygen consumption. Good to see distribution of NT and id brain dysfx due to stroke, epilepsy, tumor, dementia, etc.
SPECT ....lower resolution PET
FMRI...same as MRI but also gives info on brain activity by detecting changes in blood oxygenation.
What is a stroke and discuss the two kinds.
Stroke is a cerebrovascular event...onset of neurological symptoms due to interruption or severe decrease in blood flow to the brain.
Ischemic stroke...most common
Hemorrhagic stroke...weakens blood vessel in brain ruptures, leaks
What are the risk factors for stroke?
Risk factors: hypertension *
Other types heart disease. Diabetes
Over 55, male,
Black, family hx
What are the symptoms of a stroke that comes from the middle cerebral artery?
Most often involved in stroke.
This artery supplies blood to parts of frontal, temporal, and parietal lobes and the basal ganglia.
And hemiparesis (face and arm).
Contralateral visual field loss both eyes
Aphasia (if dominant hem is affected)
Denial of deficit if nondominant hemisphere is affected.
Where is the location of an anterior cerebral artery and what symptoms result?
Frontal and parietal lobe, corpus collosum, caudate nucleus
Effects...contralateral hemiplegia (leg). ..impaired judgement , insight
Where is the posterior cerebral artery and what are the symptoms?
Supplies blood to thalamus, temporal lobe, occipital lobe
Traumatic brain injury can be open or closed (widespread damage, lose cs, blow doesn't penetrate skull) and is classified as mild, moderate, or severe based on what indicators?
Prognosis related to severity and location , age, premorbid, etc
Most recovery first 3 mo to one yr
Many sx indefinitely
Anterograde amnesia (post traumatic) is good predictor of outcome.
Glasgow coma scale GCS,
Post traumatic amnesia PTA
Loss of consciousness LOC
Mild...GCS 13 to 15;
PtA less 1 hr;
LOC 30 min or less or none
Moderate... GCS. 9 to 12
PTA...1 to 24 hours
LOC ...30 mins to 24 hrs
Severe...GCS 8 or less
PTA more 24 hrs
LOC more 24 hrs
What is required for a postconcussional disorder?
Significant concussion following head trauma noted by:
Loss of cs, ptraumatic amnesia, and/or post traumatic seizures
Plus impaired attention/memory
And 3 plus sx for at least 3 mo
Fatigue, headache, dizziness, irritability, aggression, anxiety, depression, personality change, apathy.
Describe the deficits with Huntington's disease. Degenerative disease.
Autosomal dominant gene disorder e 50 percent chance of inheriting.
Linked to prob in basal ganglia and cortex (MRI shows reduced volume in bg; PET shows reduced metabolic brain activity)
Glutemate, Ach, GABA, and dopamine abnormalities.
Sx...first signs 30 to 50 yrs
Affective (depression, anxiety, lability). May get wrong dx.
Then personality change, forgetfulness, motor sx
Later athoetosis (slow writhing) and chorea (involuntary rapid, jerking of face, limbs, trunk.
Later dysphasia (diff swallow), immobility, and dementia.
Hi suicidality. ESP if young.