Karteikarten

Ch 5 Psych

Icecream M Psych Englisch 125 Karten

Karten in diesem Stapel (125)

1Process of sensation/perception
2explanations for synaesthesia-Pruning of neural connections that occurs in infancy doesn't occur in people with synesthesia, so they retain these connections
-Diffusion tensor imaging: Lights up white matter pathways, increased connectivity in synesthetes
-Deficit in neural inhibitory processes that keep sensory info from "overflowing" into other areas
3sensationstimulus-detection process by which our sense organs respond to and translate environmental stimuli into nerve impulses that are sent to the brain
4perceptionmaking sense of what our senses tell us, actively organizing stimulus input and giving meaning
5transductionprocess where characteristics of a stimulus are converted into nerve impulses
6psychophysicsstudy of how physical stimuli are translated into psychological experience
7stimulusinfo in environment picked up by NS receptors
8sensationbegins with a detectable stimulus
9who developed the concept of the thresholdFechner
10absolute thresholdLowest intensity at which a stimulus can be detected correctly 50% of the time (lower the threshold, the greater the sensitivity)
11Threshold for 5 senses□ Vision-candle flame seen from 50km
□ Hearing- watch ticking from 6m
□ Taste-tsp of sugar in 7.5L of water
□ Smell-one drop of perfume diffused in a large apartment
□ Touch-wing of a fly/bee on cheek from dist. 1cm
12Differences threshold/Just Noticeable Differenceminimal amount the stimulus needs to be increased/decreased to be judged as diff from the original stimulus
13Weber's Lawjnd is directly proportional to the magnitude or strength of the stimulus with which the comparison is being made (expressed as a Weber fraction, smaller the more sensitive)
14Weber fraction for Kinesthesis (lifted weights)1/50 $Weber fraction for Kinesthesis (lifted weights)$
15weber fraction for Touch (pressure applied to skin)1/7
16Smell (india rubber)1/4
17weber fraction for audition (tonal pitch)1/333 (most sensitive) $weber fraction for audition (tonal pitch)$
18weber fraction for vision (brightness)1/60 $weber fraction for vision (brightness)$
19weber fraction for pain (heat reduced)1/30 $weber fraction for pain (heat reduced)$
20audition (loudness)1/20
21taste (salt concentration)1/3 (least sensitive)
22subliminal stimulusone that is weak/brief, received by the NS, cannot be perceived consciously (below absolute sensory threshold)
23James Vicary studyJames Vicary flashed "drink Coca cola" and "eat popcorn" and claimed it caused sales to increase. But further research showed that stimuli above the absolute threshold are far more influential than subliminal attempts
24Krosnick studyshowed photographs (baby vs. burning house, fast so ppl weren't aware of what they had seen)followed by unpleasant or pleasant subliminal stimuli
Found that subliminal stimuli have little effect on behaviour but small effect on attitudes
25Prosopagnosiaunable to recognize familiar faces, type of visual agnosia (Usually have cortical damage in lateral occipital area (LOA) in both hemispheres)
26Steeves studystudied D.F. (Can perceive colour/texture, or can identify people from non-facial cues such as clothing/voice pitch)
Found that higher order facial recognition occurs in LOA, FFA/fusiform facial area, and visual cortex
(DF could still get some info about stimuli even when one area was damaged)
27Merikle: biasing perceptionsubliminal cues can bias what we perceive at a conscious level and may alter our conscious experience of stimuli
28Todorov and Bargh: subliminal aggressionsubliminal presentations of aggressively toned words causes ppl to judge behaviours of others as more aggressive, increases own tendency to behave aggressively
29Radel: subliminal motivationexposure to subliminal motivational messages increases perseverance
30is absolute threshold accurate?psychologists say no: There is a range of uncertainty based on ppl's DECISION CRITERION (how certain they must be before they say they detect a stimulus)
31signal detection theoryfactors that influence sensory judgements, how certain someone needs to be to make a decision
32influences on signal detection-at low intensities, both situation and participant affect it
-influenced by rewards/costs of saying yes/no
-experience causes lower threshold
-bold people have more hits/misses
33Sensory neurons are engineered to respond to a constant stimulus by ______________ activitydecreasing
34sensory adaptationdiminishing sensitivity to unchanging stimulus over time
35Pritchard studyshowed stabilized image on retina and found that adaptations allows us to pick up on changes from the constant
36Vision process
37Myopianearsightedness, image is focused in front of retina, eyeball is longer than normal
38Hyperopiafarsightedness, lens doesn't thicken enough, image is focused behind retina, eyeball becomes shorter (e.g. due to aging)
39Astigmatismrefractive errors due to curvature of cornea or multiple/lack of specific focal point
40anatomy of the eye
41rods(120 million)
-Best in dim light, black and white
-500 times more sensitive than cones
-Found throughout the retina (periphery of retina) except fovea
42cones(6 million)
-Colour, day
- Fovea-centre of retina, only cones
- Cones decrease in concentration as you move away from centre of retina
-Important for visual acuity/detail
-share bipolar cells, but in fovea each fires to one
43how do rods and cones send messages?Bipolar cells-synaptic connections with rods and cones, many rods connected to same bipolar cell
Synapse with layer of ganglion cells
These axons form bundle, optic nerve
44blind spotoptic nerve exits from back of eye and produces a blind spot (no photoreceptors), perceptual system fills in visual field
45visual acuity(ability to see fine detail) is greatest when image goes directly on fovea b/c many cones fire and private-line bipolar cells
46visual transductionCharacteristics of a stimulus are converted into nerve impulses
47process of transduction1. Light waves=> nerve impulses due to proteins called photopigments
2. They absorb light, changes rate of neurotransmitter release at bipolar cells
3. Greater change=stronger signal
4. If nerve signals triggered at each level (rod/cone, bipolar, ganglion cell), signal is sent right away to thalamus and visual cortex
48Rods have greater brightness sensitivity for colour except...red
49Cones most sensitive for _______ in low illuminationgreen-yellow
50Dark adaptationimprovement in brightness sensitivity under low light conditions
-Photoreceptor absorbs light, depleted of pigment for time, pigment must be regenerated
-Cones gradually increase sensitivity until they reach a max
-Rods regenerate more slowly
51In WWII, pilots were given goggles with red lenses/red lights in rooms b/conly cones would be stimulated and rods would be ready for dark adaptation
52additive colour theoryoverlap of light RBG produces colour
53subtractive colour theorynot all wavelengths are absorbed, rest are reflected to eye
54Trichromatic theoryYoung and Helmholtz: there are 3 colour receptors in retina
□ Individual cones are most sensitive to RBG
□ Activation of all three causes white colour
55problems with trichromatic theory-Thinks yellow is from RG, but RG colour blind people can see yellow
-Can't explain Colour afterimage
56opponent process theoryHering: 3 types of cones, each cone responds to 2 diff wavelengths
R/G, B/Y, Black/White (diff chemical reactions for each)
57explanation for afterimagestaring causes neural processes to be fatigued, white surface reflects all wavelengths, "rebound" reaction occurred where each receptor responded with opposite reaction
58dual process theoryCombines two vision theories:
-Cones DO contain 3 diff photopigments most sensitive to RBG
-Different ratios of activity leads to diff colours
-Not in cones, ganglion cells, retina and higher visual cortex
-Ganglion cells in retina and neurons alter rate of firing (opponent process)
-RG triggered by RG cones, but B sensitive cones directly stimulate blue process, Y is caused by input of both RG cones
59trichromatnormal colour vision
60two types of colour deficient visionabsence of photopigment in certain cones
dichromats=colour blind in one system
monochromats=totally colour blind (black/white)
61visual reconstructionPoint to point correspondence b/w retina and visual cortex
All info sent to visual association cortex
At least 10 duplicate maps of retina
62feature detectorsneurons in cortex receive input from retina, respond maximally to specific info (e.g. orientation, colour)
(ganglion cells might act like feature detectors)
63Parallel processingdifferent aspects of image are analyzed at the same time
64Blakemore and Cooper: critical periods for vision experimentKittens raised w only vertical lines or only horizontal lines for 5h/day, and rest of time darkness
If raised in vertical environment, would only track vertical events, feature detectors didn't fire for horizontal
Eventually adapted to new environment
Muir and Mitchell: Kittens raised in vertical striped room could discriminate patterns as well as normal kittens but ability to see horizontal patterns was diminished
65critical period for vision-cataractspeople born with cataracts were deprived of normal visual stimuli
If cataracts removed before age 10, normal vision
If cataracts not removed early, many problems with visual acuity. Could perceive figure ground relations, scan objects, follow moving targets w eyes. But couldn't identify shapes and poor perceptual constancies.
66frequency range that humans can detect20Hz to 20 000Hz
67amplitudeheight of wave above zero air pressure, amount of compression/expansion, (loudness)
Decibels, logarithmic scale
68ear anatomy
69auditory parts1. Eardrum-tympanic membrane that vibrates
2. Middle ear-cavity with 3 bones: (amplifies more than 30x) hammer/malleus-attached to eardrum, anvil/incus, stirrup/stapes-attached to oval window (boundary b/w middle and inner ear)
3. Cochlea-snail shaped, filled with fluid, contains…
4. Basilar membrane-tissue sheet
5. Organ of Corti-rests on membrane, contains 16 000 hair cells=sound receptors
70auditory transduction process
71How do we detect loudnessHigh amplitude causes more vibrations in basilar membrane, hair cells to bend more
→ release more neurotransmitter, higher firing rate of auditory neurons
→ Certain cells only respond to very loud sounds
72frequency theorynerve impulses per second match f of sound wave
BUT, neurons are limited in firing rate, so neurons can't produce high frequencies for over 1000Hz (so only useful for less than 1000Hz)
73place theory(Hermann von Helmholtz) specific point in cochlea where fluid wave peaks and bends hair cells is the frequency coding cue
Diff frequencies stimulate diff areas on basilar membrane
74Bekesy experiment-place theorycut holes in cochleas to see what happened when they were stimulated with diff frequencies (works for more than 1000Hz)
Found that:
High f=abrupt wave close to oval window/base of basilar
Lower f=slower wave further down canal/tip of cochlea
75how is sound localizedNS uses info from time and intensity diff of sounds from BOTH ears to locate source of sounds (binaural ability)
we can detect as little as 1/100 000 sec
Difficult to determine when right in front or overhead
76Conduction deafnesscaused by problems involving mechanical system that transmits sound waves to cochlea
Hearing aid helps
77Nerve deafnessdamaged receptors in inner ear or auditory nerve damage
Cannot be helped by hearing aid
Caused by aging, disease, exposure to loudness (loss of hair cells)
78vestibular systembody orientation or equilibrium
Semi circular canals fill with fluid, lines of hairs each operating on a diff plane (L/R, up/down, forward/back)
Respond only to acceleration/deceleration
79Tonotopic organizationauditory cortex-Specialized neurons respond maximally to sounds of diff frequencies in both primary and secondary auditory cortex
80Taste budschemical receptors on edges and back surface of tongue (9000)
81Umamisavoury taste sense, caused by protein activation
82gustation processSubstances dissolve and interact with saliva, chemical flow into taste pore, stimulates receptor cells, sent to brainstem, thalamus, gustatory cortex
83olfactory receptorslong cells/tiny olfactory cilia project through lining of upper nasal cavity, into mucous membrane (resemble neurotransmitter receptor sites)
One theory: detect odours individually, not sum of diff receptors
84Olfactory processReceptors send input to olfactory bulb (forebrain, above nasal cavity)
Each chemical excites certain portion of bulb, odours coded by part excited
85Pheromoneschemical signals in natural body scents affect human behaviour subtly
86Menstrual synchronytendency of women who live together/close friends to become similar in cycles (But doesn't occur with prolonged/intensive contact)
87Free nerve endingsprimary receptors for pain and temp, nerve cell's beneath skin's surface
88Nerve fibres at base of hair folliclereceptors for touch and light pressure
89centre surround receptive fieldsskin and neurons organized in the following way:
90somatotopic organizationsensory homunculus in somatosensory cortex
91phantom limb conditionbrain locates sensations not present, when nerves that used to be in limb are irritated (usually disappears with prosthetic limbs)
92where are pain receptors not foundPain receptors are everywhere except brain, bones, hair, nails and nonliving parts of teeth
93Two different pathways of pain-Sharp/brief/A Delta fiber
-Dull/throbbing/C fiber
94gate control theoryMelzack and Wall: Pain results from events in spinal cord that open/close spinal gates, send impulse to brain
Acupuncture, scratching itch, rubbing bruise=> stimulate receptors that close pain gates
95role of immune systemglial cells create/maintain pain
-Become activated by infection and by substances released by neurons
-Amplify pain by releasing cytokines, cause inflammation
96psychosomatic disorderspain in the absence of physical causes
97KinesthesisMuscle and joints' positions/movement
98receptors for kinesthesisnerve endings in muscles, joints, tendons
99Vestibular sensesense of body orientation and equilibrium
100Sensory prosthetic devicesprovide input for lack of ability of sensory receptors
101Sonicguidesame mechanism as echolocation
Glasses have transmitter that emits high f sound waves beyond range of human hearing
Sound waves bounce off objects, back to Sonicguide, wearer learns to interpret diff sounds
102tactile/tongue-based sensor to substitute visual input (BrainPort V100)→ Moist surface conducts electricity
→ Stimulator takes data from visual image into tongue stimulation
→ Can also help soldiers locate objects in dark or firefighters
103Retinal implants (Argus II bionic eye system)→ Receptors replaced with prosthetic sensor
→ Camera on glasses sends signals to electrode array in retina, stimulates bipolar cells
→ Only light and dark contrast
If bipolar layer is damaged, can convert visual image into light pulses directly to ganglion cells (were treated w gene therapy)
104Cortical implants→ Cell stimulation in visual cortex causes flashes of light called phosphenes (in blind and sight ppl)
→ Specific pattern of stimulation of cortex neurons=phosphene pattern for shapes of letters/objects
→ Ppl wear darkened goggles that produce these patterns
→ Can also learn cortical Braille for reading purposes
105Cochlear implantsfor nerve deafness
→ Electrodes around cochlea can stimulate auditory nerve
→ Microphone sends sound waves to bone, broken down into f, sent to cochlear areas
can also have an auditory brainstem inserted
106Bionic Hand/SmartHand→ 40 sensors connected to sensory nerves in amputee
→ Four motors are linked to brain, attached to motor nerves
→ Soldiers who have lost hands will receive these
107Bottom up processingsystem takes in individual elements of the stimulus and combines them into a unified perception (e.g. visual system as you read)
108top down processingsensory info is interpreted w other knowledge, ideas, expectations
109shadowinghow attention and perception are studied: ppl get two messages in each ear and must repeat/shadow one message
110Inattentional blindnessfailure of unattended stimuli to register in consciousness
111Environmental/personal factors towards attention- Attracted by intensity, novelty, movement, contrast, repetition
- Internal factors (motives/interests)
-relevance to well being (e.g. attracted to fearful stimulus)
-Ability to see things in periphery is greater for animal stimuli than letters/numbers
112figure ground relationsorganize stimuli into central/foreground and background
113four Gestalt laws→ Similarity-parts of a configuration perceived as similar will be perceived as belonging together
→ Proximity-objects near each other perceived as part of same configuration
→Closure-close open edges/fill gaps
→ Continuity-link individual elements to form continuous line/pattern
114personal schemamental representation/image to compare stimulus with (top down)
Gregory: each perception is a hypothesis about an object/meaning of sensory info
e.g. Mona Lisa: when looking at background, emphasizes smile. Looking at mouth, makes smile disappear
115Perceptual setreadiness to perceive stimuli in a certain way
e.g. Harold Kelley: brought in lecturer, gave students expectations of warm or cold person
116Perceptual constanciesallows us to recognize familiar stimuli in diff conditions
Shape constancy-recognize things from diff angles
Brightness constancy-relative brightness remains same under diff light conditions (ratio of light intensity b/w object and surroundings are constant)
Size constancy-size of objects remain constant even if images on retina change in size w diff distance
117retina receives info of ____ and ______length and width
118brain translates info into 3D image by using:monocular and binocular cues
119monocular cues(only requires one eye)
→ Light and shadow
→ Linear perspective, parallel lines converge as they recede into the distance (also one on horizon seems larger)
→ Interposition-closer objects may cut off part of our view of further ones
→ Height in horizontal plane
→ Texture-grain appears finer as dist. Increases
→ Clarity
→ Relative size-smaller is further
→ Motion parallax-if we are moving, closer objects move faster in opp direction than far ones
120binocular cues(both eyes)
→ Binocular disparity-each eye sees a slightly diff image (Some feature detectors respond only to stimuli in front/behind point of fixation)
→ Convergence-muscle feedback that turn eyes inward to view closer object (More convergence for closer objects than farther)
121Illusion of smooth motionsequential appearance of 2 or more stimuli
122Wertheimer: stroboscopic movement (phi phenomenon)when light flashed in darkness, then seconds later, flashed nearby (looks like continuous motion)
123illusions result from_________faulty hypothesis testing
124critical periodscertain experiences must occur if perceptual abilities and brain mechanisms are to develop normally
125critical period in humans for visionbirth to 10y (Maurer)