Perception Flashcards
Young-Helmholtz Trichromatic theory
3 types of color receptors (cones) - receptive to a diff primary color
Hering’s opponent-process theory
3 types of bipolar receptors: red-green, yellow-blue, white-black
supported by negative afterimages
thalamus
depth perception
combination of binocular (close distance) and monocular (great distance) cues
retinal disparity
our 2 eyes see objects from 2 different views; closer the object, greater the disparity
synesthesia
joining senses; rare condition
hear a color or taste a shape
limbic system?
psychophysics laws
developed to identify absolute thresholds and difference thresholds
absolute - minimum stimulus needed to produce a sensation
difference - smallest increment in stimulus intensity needed to recognize the discrepancy between the stimuli
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
Fechner’s law
physical stimulus changes are logarithmically related to psychological sensations; a person’s experience of stimulus intensity increases arithmetically as stimulus intensity increases geometrically
Steven’s Power Law
address extreme intensities
description of sensation as an exponential function of stimulus intensity - possible to predict that doubling the intensity of a light less than doubles the sensation of the light’s brightness; doubling intensity of electric shock more than doubles physical sensation
temporal lobes
encoding, storage, and retrieval of long-term memories
right lobe: nonverbal memory tasks
left: verbal memory
hippocampus
consolidating LT declarative memories, but not storage explicit memory (conscious recollection)
neural mechanisms
study of sea slug (Aplysia)
ST memory - changes at existing synapses
LT memory - increase in number of synapses and modification to structure
long-term potentiation - greater responsively of a postsynaptic neuron to low-intensity stimulation by a presynaptic neuron for hours, days, weeks after presynaptic neuron has been barraged by high-frequency stimulation
protein synthesis - LT memory depends on this in minutes or hours after learning
Broca’s aphasia
expressive, motor, and confluent aphasia
speak slowly and with great difficulty
anomia (can’t name object)
frustration, anxiety, depression
Wernicke’s aphasia
trouble understanding written and spoken language and generating meaningful language
speech is rapid, seems effortless - largely devoid of content
often unaware that speech is meaningless
Conduction aphasia
anomia, paraphasia, impaired repetition
Transcortical aphasia
caused by lesions outside broca and wernicke’s area
transcortical motor - damage isolates only broca’s area
transcortical sensory - isolates only Wernicke’s area
James-Lange theory
importance of peripheral factors: emojified represent perceptions of bodily reactions to sensory stimuli
“you are afraid because your knees are shaking”
quadriplegics - have less intense emos
Cannon-Bard theory
emphasis on brain mechanisms
emotional and bodily reactions to stimuli occur simultaneously as a result of thalamic stimulation of the cortex and peripheral NS
research - bodily reactions are fairly similar for all emo
Two-factor theory
Schahter and Singer; epinephrine study
combo of physiological arousal and cognitive interpretation of that arousal
cognitive appraisal theory
Lazarus
emotions are universal, but there are differences in how emotion arousing events are interpreted or appraised
primary appraisal: situation as irrelevant, positive-benign, or stressful
secondary appraisal - eval of resources to cope with a situation that is stressful
re-appraisal - monitors and modifies appraisals
Papez’s circuit
neural circuit that mediates experience and expression of emotion
hippocampus, mammillary bodies, anterior nuclei of thalamus and cingulate gyrus
Cerebral cortex
L hemisphere: happiness and positive emotions; damage: depression, anxiety
R hemisphere: sadness, fear, negative emotions; damage: indifference, apathy, lability, extra cheerfulness; dominant for recognition and expression of emotion
hypothalamus
translation of emotion into physical responses
General adaptation syndrome (3 stages)
Selye
physiological reactions to stress - edited by adrenal and pituitary glands
alarm
resistance
exhaustion
type A behavior pattern
highly competitive, achievement oriented, hostile, easily irritated
hostility - most associated with health problems
sexual dimorphism
size of certain regions: corpus callosum, hippocampus, SCN
related to differential exposure to androgens during prenatal and early postnatal development
secondary sex characteristics
pubic hair, hips, breasts, etc - develop at puberty d/t increase in gonadal hormones
hypothalamic-pituitary-gonadal axis
hypothalamus secretes chemicals that stimulate anterior pituitary gland, when then releases the gonadotropic hormones that stimulate testosterone and sperm production or ovulation and estrogen
adult sexual behavior
effects of hormones are less apparent for females
in males - there is a link bt minimum threshold of testosterone and sexual interest; beyond minimum level, not a strong relationship
Beta
alert, fully awake
Alpha
relaxed, wakefulness (early stage 1)
Theta
Stage 1-2 sleep
Delta
stage 3 and 4
deep sleep “slow wave”
REM
most vivid dreams physiology mimics being awake: increased heart rate and respiration but muscles are in paralysis active/paradoxical sleep
REM increases in length as night progresses
closed v open head injury
closed: non penetrating blow
open: penetrating (gun shot); no loss of consciousness, symptoms more local and specific
level of severity of head trauma
score on Glasgow coma scale
duration of post traumatic amnesia
duration of loss of consciousness
post traumatic amnesia (PTA)
post injury anterograde amnesia - good predictor of persistence of cognitive, motor, personality and other sx caused by injury
retrograde amnesia post TBI
recent memories more affected than remote
“shrinking”- most remote memories return first
recovery from TBI
linked to severity of injury, age, gender, SES, pre-injury physical and mental functioning
bad outcomes linked to allele e4 on ApoE gene
greatest amount of recovery occurs in first 3 mo. and then more recovery in 1st year
postconcussional syndrome (PCS)
somaticc and psychological symptoms that occur in ~50% of individuals
initially: headache, dizziness, nausea, blurred vision, drowsiness
then: insomnia, fatigue, tinnitus, cognitive impairment, irritability, depression, anxiety
combo of organic and psychological factors
Cerebrovascular accident (CVA)
stroke
sudden or gradual onset of neurological symptoms resulting from disruption of blood supply to the brain
causes: 1) thrombosis (blockage by blood clot) 2) embolism (blockage by other material) 3) hemorrhage
risk factors: hypertension and atherosclerosis (thickening of artery walls), heart attack, diabetes, cigarette, older age
depression affects up to 40% immediately, sometimes months later
Huntington’s Disease
inherited; degenerative; combo of psychiatric, cognitive, and motor symptoms
offspring have 50% chance of developing disorder; dx bt 30-50 yo
first: emotional and cognitive sx
early motor sx: fidgeting and clumsiness, facial grimaces, “piano playing” (chorea= jerky movements)
later: “dance like” gait, athetosis (slow, writhing movements)
cognitive impairments progress to exec function
loss of GABA in basal ganglia, esp caudate nucleus, putamen, globus pallid us
Parkinson’s disease
progressive degeneration of dopamine containing cells in substantial nigra
exposure to toxins may contribute
positive symptoms: tremor, muscle rigidity, akathisia (cruel restlessness)
neg sx: postural disturbances, speech difficulties, slow movement, akinesia (less spontaneous movement)
20% depression precedes sx; 50% depression at some point
initially alleviated by L-dopa
seizure
d/t abnormal electrical activity in the brain that causes 1 or more: 1) aura that signals onset 2) loss of consciousness 3) abnormal movement
generalized seizure
bilaterally symmetrical; no focal onset
tonic-clonic (grand mal) and absence
tonic-clonic: tonic = muscles contract and bod stiffens; clonic= rhythmic shaking of limbs; postictal depression or confusion
absence (petite mal)- brief attacks of loss of consciousness without prominent motor symptoms (thalamus)
partial seizures
often begin on one side of brain and affect one side of body initially, but can spread
simple: no loss of consciousness
complex: some alterations in consciousness
temporal lobe epilepsy= most common cause of partial seizures
hypertension
primary: high blood pressure is not due to a physiological cause (85-90% of cases) “silent killer”
secondary: elevated blood pressure is related to a known disease
risk factors: family hx of hypertension, obesity, smoking, salt, stress, old age
older > younger
AA > white
men> women UNLESS old and AA
migraine headache
usually limited to one side of head, accompanied by nausea, vomitting, diarrhea, constipation and sensitivity to light, noise, odors
12% classic - aura
common migraine - no aura but other sx can signal
F> M
constriction and dilation of blood vessels and low serotonin
cluster headache
excruciating, usually burning pain that occurs in clusters 1+ a day for 2-3 mo
usually behind one eye
tension headache
non throbbing pain, usually on both sides of the head, back of the neck, or facial area; pressure or tightness
PMS
30-80%
only 1.8-5.8% severe enough to meet criteria for premenstrual dysphoric disorder
placebos, SSRI, CBT
hyperthyroidism
Grave’s disease
speeded-up metabolism, elevated body temp, heat intolerance, increased appetite with weight loss, rapid heart rate, agitation, emo lability, fatigue, insomnia
hypothyroidism
slowed metabolism, reduced appetite with weight gain, slowed heart rate, lower body temp, lethargy, depression, decreased libido, apathy, confession, impaired concentration and memory
hypoglycemia
low blood glucose: hunger, dizziness, headaches, blurred vision, palpitations, anxiety, depression, confusion
diabetes mellitus
hypoinsulinism (excessive blood glucose)
