4: Sensation and Perception Flashcards
wavelengths longer than visible light (3)
- INFRARED waves
- MICROWAVES
- RADIO waves
vision, hearing n touch (2)
- ENERGY senses
- gather energy in the form of LIGHT, WAVES, n PRESSURE
wavelengths shorter than visible light (2)
- ULTRAVIOLET waves
- X-RAYS
FACTORS that determine the COLOURS we see (2)
- LIGHT INTENSITY (BRIGHTNESS)
- LIGHT WAVELENGTH (HUE)
colors of VISIBLE SPECTRUM from LONGEST to SHORTEST wavelength (1)
- Roy G. Biv
transduction
- TRANSLATION of INCOMING stimuli into NEURAL signals
rods (3)
- cells activated by BLACK n WHITE
- OUTNUMBER cones 20 to one
- distributed THROUGHOUT retina
cones (2)
- cells that respond to COLOR
- concentrated toward CENTER of RETINA
fovea
- INDENTATION at the CENTER of the RETINA that contains the highest CONCENTRATION of CONES
transduction in vision (steps: 5)
- FIRST LAYER of cells (CONES n RODS) are activated by light –> activate next layer of BIPOLAR CELLS –> activate GANGLION CELLS (optic nerve) –> LATERAL GENICULATE NUCLEUS/LNG (thalamus) –> VISUAL CORTICES (occipital lobe)
blind spot
- spot where OPTIC NERVE leaves the RETINA (because it has no rods or cones)
optic chiasm
- spot where the OPTIC NERVES CROSS each other
ganglion cells (in retina)
(NERVE CELL whose body is outside the CNS)
- AXONS make up the OPTIC NERVE nerve that sends impulses to specific region in the thalamus (LNG)
David HUBEL n Tom WIESEL (2)
- PERCEPTION researchers
- discovered that GROUPS of NEURONS in the VISUAL CORTEX respond to different TYPES of visual images –> FEATURE DETECTORS for vertical lines, curves, motion…
Theories of color vision (2)
- TRICHROMATIC THEORY
- OPPONENT-PROCESS THEORY
TRICHROMATIC theory (3)
- hypothesizes that we have 3 types of CONES in the retina: detect BLUE, RED n GREEN
- activated in different COMBINATIONS to PRODUCE all the colors of the VISUAL SPECTRUM
- cannot explain some visual phenomena: AFTERIMAGES n COLOR BLINDNESS
Afterimages (2)
- when u STARE at a color for awhile, then look at a WHITE space, you see a color afterimage
- GREEN: afterimage is RED; YELLOW: after image is BLUE
OPPONENT PROCESS THEORY (3)
- SENSORY RECEPTORS arranged n the retina comes in PAIRS: red/green; yellow/blue; black/white
- if ONE sensor is STIMULATED, its pair is INHIBITED from firing
- explains color blindness n afterimage
sound wave measurements (2)
- AMPLITUDE: HEIGHT of wave + LOUDNESS (DECIBELS)
- FREQUENCY: LENGTH of the waves + PITCH (MEGAHERTZ)
parts of the ear (7)
- EAR CANAL
- EARDRUM (tympanic membrane)
- HAMMER (malleus)
- ANVIL (incus)
- STIRRUP (stapes)
- OVAL WINDOW
- COCHLEA
organ of Corti
- NEURONS activated by MOVEMENT of the HAIR cells on the BASILAR MEMBRANE
basilar membrane (2)
- on the FLOOR of the COCHLEA
- lined with HAIR CELLS
pitch theories (2)
- PLACE theory
- FREQUENCY theory
PLACE theory
- holds that HAIR CELLS in the cochlea RESPOND to different FREQUENCIES of sound based on where they are LOCATED in the COCHLEA
FREQUENCY theory
- we sense PITCH because the HAIR CELLS fire at different RATES (frequencies) in the cochlea
types of deafness (2)
- CONDUCTION deafness : occurs when sth goes wrong w. the SYSTEM of CONDUCTING SOUND to the cochlea
- NERVE (sensorineural) deafness : hair cells in cochlea are damaged
gate control theory (3)
- explains how we EXPERIENCE PAIN the way we do
- some pain MESSAGES have HIGHER PRIORITY than others
- when you scratch an itch, you feel scratching so itch is temporarily gone
color blindness (2)
- DICHROMATIC color blindness (can’t see red/green or blue/yellow shades)
- MONOCHROMATIC (see only shades of gray)
papillae
- BUMPS you can see on your TONGUE
- TASTE BUDS are located on papillae
types of taste (5)
- sweet
- sour
- salty
- bitter
- unami (“meaty” “savory” taste)
Chemical senses (2)
- TASTE
- SMELL
how we smell (4)
- MOLECULES of SUBSTANCES rise into the AIR n DRAWN into NOSE
- molecules settle into MUCOUS MEMBRANE at the top of each nostril
- absorbed by OLFACTORY RECEPTOR CELLS (researchers estimate approx 100 different types)
- receptor cells linked to OLFACTORY BULB
olfactory bulb (2)
- gathers messages from OLFACTORY RECEPTOR CELLS n sends the information to the AMYGDALA, then the HIPPOCAMPUS (vs. thalamus)
- explains reason why POWERFUL trigger for memories?
Body position senses (2)
- VESTIBULAR SENSE
- KINESTHETIC SENSE
VESTIBULAR sense (4)
- tells us how our BODY is ORIENTED in SPACE
- 3 SEMI-CIRCULAR CANALS in INNER EAR give the brain feedback about body orientation
- when POSITION of HEAD changes, FLUID in canal moves, ACTIVATING HAIR CELL SENSORS, which sends info to brain
- NAUSEA n DIZZINESS when FLUID in CANALS is AGITATED
KINESTHETIC sense (3)
- keeps track of POSITION and ORIENTATION of SPECIFIC BODY PARTS
- allows you to touch kneecap w. finger bcos kinesthetic sense provides INFORMATION about where your finger is IN RELATION to your kneecap
- RECEPTORS in our MUSCLES n JOINTS send information to brain
Psychophysics DEF
- study of INTERACTION b.w SENSATION n PERCEPTION (how we experience sensation)
absolute threshold
- SMALLEST amount of STIMULUS we can DETECT 50% of the time
- absolute threshold for VISION: single candle flame about 30 miles away on a perfectly dark night
- SMELL: single drop of perfume a room away
subliminal messages
- STIMULI BELOW our ABSOLUTE THRESHOLD
- COMPANIES claim that subliminal messages can change UNWANTED BEHAVIOR; “lose weight”, “increase your vocabulary”
difference threshold (3)
- JUST-NOTICEABLE DIFFERENCE
- SMALLEST amount of CHANGE needed in a STIMULUS before we DETECT a change
- computed by WEBER-FECHNER law
WEBER-FECHNER law (3)
- Ernst WEBNER n Gustav FLECHNER (psychophysicists)
- states that the CHANGE NEEDED is PROPORTIONAL to the ORIGINAL INTENSITY of the stimulus (the more INTENSE the stimulus, the MORE CHANGE it will need be4 we detect a difference)
- e.g. amount of spice to a dish that didn’t have any spice be4 vs +spice in a dish that already has spice
WEBER additional discovery (3)
- esch sense VARIES ACCORDING to a CONSTANT
- e.g. constant for hearing is 5 percent: tone would have to increase 5 decibels (100-105) be4 we notice it is louder
- e.g. constant for vision is 8 percent: 8 candles would have to be added to 100 candles be4 we notice any difference
perceptual theories (3)
- SIGNAL DETECTION theory
- TOP-DOWN processing
- BOTTOM-UP processing
SIGNAL DETECTION theory (4)
- investigates the effects of the DISTRACTIONS n INTERFERENCE we experience while percieving the world
- tries to predict what we see among COMPETING CRITERIA
- takes into account RESPONSE CRITERIA
- tries to EXPLAIN n PREDICT the different PERCEPTUAL MISTAKES we make (FALSE POSITIVE/FALSE NEGATIVE)
response criteria (3)
- RECIEVER OPERATING CHARACTERISTICS
- how MOTIVATED we are to detect a certain stimuli
- e.g. more likely to smell pumpkin pie if i am hungry and like the taste of pumkin pie
perceptual mistakes (2)
- FALSE POSITIVE: when we think we PERCIEVE a stimulus that is NOT THERE; seeing a friend on a crowded street and end up waving at a stranger
- FALSE NEGATIVE: NOT PERCIEVING a STIMULUS that is present; not notice the directions at the top of the test that instruct not to write on the test
TOP-DOWN processing (4)
- occurs when you use BACKGROUND KNOWLEDGE to FILL IN GAPS in what you percieve
- FASTER but more PRONE to ERROR
- e.g. see images in CLOUDS
- e.g. backmasking
schemata (2)
- MENTAL REPRESENTATIONS of how we EXPECT the world to be
- schemata can create a PERCEPTUAL SET
perceptual set DEF.
- PREDISPOSITION to PERCIEVING sth a CERTAIN WAY
backmasking (2)
- supposed HIDDEN MESSAGES MUSICIANS RECORDED BACKWARD in their music
- ppl who listened to the songs played backward and had SCHEMATA of this music as dangerous or evil PERCIEVED the THREATENING messages due to TOP-DOWN processing
BOTTOM-UP processing
- aka FEATURE ANALYSIS
- use FEATURES of an OBJECT itself to build a COMPLETE PERCEPTION
- takes LONGER but is more ACCURATE
figure-ground relationship (3)
- a PERCEPTUAL DECISION
- what PART of the VISUAL IMAGE is the FIGURE and what part is the ground or the BACKGROUND
- several OPTICAL ILLUSIONS play w. this rule (picture of the vase that is also two faces)
FACTORS that influences how we GROUP OBJECTS (4) (GESTALT RULES)
- SIMILARITY: similar in appearance
- PROXIMITY:
- CONTINUITY: form a continuous form (trail, geometric figure)
- CLOSURE: similar to top down processing; objects that make up a recognizable image are more likely to be percieved as objects belonging to the same group.
constancy DEF.
- our ABILITY to MAINTAIN a CONSTANT PERCEPTION of an OBJECT despite VARIATIONS in LIGHT, ANGLE of VISION, and so on…
types of constancy (3)
- SIZE constancy: we keep a CONSTANT SIZE in MIND of an object and know that it does not GROW or SHRINK in size as it moves CLOSER n FARTHER away
- SHAPE constancy: objects viewed from DIFFERENT ANGLES will PRODUCE different SHAPES on our RETINAS, but we know the shape of an object is CONSTANT; e.g coffee mug viewed from side and above.
- BRIGHTNESS constancy: we PERCIEVE objects as being CONSTANT in COLOR, even as the LIGHT REFLECTING off of the object CHANGES; e.g. Brick red wall at night
situations where we perceive objects to be MOVING, when they are NOT (3)
- STROBOSCOPIC effect
- PHI phenomenon
- AUTOKINETIC effect
STROBOSCOPIC effect (2)
- IMAGES on a SERIES of STILL PICTURES PRESENTED at a CERTAIN SPEED will appear to be MOVING
- movies, flipbooks
PHI phenomenon (2)
- a SERIES of LIGHTBULBS turned ON and OFF will appear to be ONE MOVING LIGHT
- holiday lights
AUTOKINETIC effect (1)
- if a SPOT OF LIGHT is PROJECTED steadily onto the same place on a wall of an otherwise DARK FOOM and people are asked to STARE at it, they will REPORT seeing it MOVE
CUES that we use to perceive DEPTH (2)
- MONOCULAR cues
- BINOCULAR cues
MONOCULAR cues (5)
- LINEAR perspective: railroad track that runs awayf rom viewer into the distance: draw two lines that converge somewhere toward top of paper
- RELATIVE SIZE cue: draw boxcars closer to viewer as LARGER than the engine off in the distance
- INTERPOSITION cue: objects that BLOCK the VIEW of other OBJECTS must be CLOSER to us
- TEXTURE GRADIENT: draw rocks closest to the viewer in detail, while the landscape of int he distance would not be as detailed
- SHADOWING: IMPLY where LIGHT SOURCE is and thus imply DEPTH and POSITION of OBJECTS
BINOCULAR cues (2)
- BINOCULAR (RETINAL) DISPARITY: EACH of our EYES sees an object from a SLIGHTLY DIFFERENT ANGLE. (the closer an object, the more DISPARITY there will be B.W the IMAGES COMING frome EACH eye)
- CONVERGENCE: the more the eyes CONVERGE, the CLOSER the object must be (brain recieves feedback from the muscles controlling eye movement)
effects of culture on perception examples (2)
- cultures that do not use MONOCULAR DEPTH CUES in their ART do NOT SEE DEPTH in PICTURES using those CUES
- some OPTICAL ILLUSIONS are NOT PERCEIVED the SAME WAY by PEOPLE from DIF. CULTURES: people who come from NON CARPENTERED cultures that do not use right angles and corners are not fooled by the MULLER-LYER illusion
Gestalt psychologists (4)
- beginning of 1900s
- described the PRINCIPLES that GOVERN how we PERCEIVE groups of objects
- pointed out that we NORMALLY PERCEIVE images as GROUPS, not as ISOLATED ELEMENTS
- thought that this process was INNATE and INEVITABLE
Eleanor GIBSON (3)
- VISUAL DEPTH experiment: INFANT placed on top of a GLASS TOPPED TABLE that creates the IMPRESSION of a CLIFF
- RESULTS: infant old enough to CRAWL will NOT crawl across the visual cliff, IMPLYING the child has depth perception
- other experiments demonstrate that we develop depth perception at about THREE MONTHS OLS