Unit 3 Flashcards
Sensation and Perception
sensation
process of sensory receptors and nervous system receiving and representing stimulus energy from our environment
perception
process of organizing and interpreting sensory info thus recognizing meaningful things/events
sensory receptors
sensory nerve endings that respond to stimuli
bottom up processing
analysis starts at receptors and works up to higher levels of processing
top down processing
constructs perceptions from sensory input by drawing on experiences and expectations
selective attention
consciously focusing awareness on specific stimulus
inattentional blindness
failing to see VISIBLE objects when attention is diverted elsewhere
change blindness
failing to notice CHANGES in the environment
transduction
conversion of one energy form into another (physical sensory energy into neural impulses)
absolute threshold
minimum stimulus energy needed to detect particular stimulus 50% of the time
signal detection theory
assumes there’s no universal absolute threshold but detection depends on person’s mood expectation alertness etc
subliminal
noise below one’s absolute threshold for conscious awareness
difference threshold
minimum difference between stimuli for detection 50% of time until we notice JUST NOTICEABLE DIFFERENCE
weber’s law
2 stimuli must differ by a % not a fixed amount
sensory adaptation
decreased sensitivity to constant stimulation
sensory habituation
decreased reaction to stimulus after periodic exposure
priming
activation (often unconsciously) of certain associations predisposing perceptions memory and responses
perceptual set
mental processes color perceptions from CONTEXT
extrasensory perception
claimed perceptions possible without sensation
short wavelength/high frequency
BLUE colors / HIGH pitch
long wavelength/low frequency
RED colors / LOW pitch
great amplitude
BRIGHT colors/LOUD noises
small amplitude
DULL colors/QUIET noises
cornea
he transparent part of the outer covering of the eye, through which light first passes
iris
muscle controls pupil and dilates it to let light in
lens
behind pupil focuses light rays into image
retina
receives upside down image contains receptors to receive light rays
accommodation
changes lens curvature or thickness based on focus’ distance
rods
retinal receptors that detect black white and gray; sensitive to movement; peripheral & twilight vision
cones
retinal receptors concentrated near center of retina; function in well lit condition; detect fine detail and color sensation
blind spot
point at which optic nerve leaves eye no receptors there
young-helmholtz trichromatic theory
retina contains 3 different types of color receptors sensitive to red green or blue; stimulating together to create any color
opponent process theory
opposing retinal processes (red-green; blue-yellow; white-black) enable color vision; some cells are stimulated by green but inhibited by red
feature detectors
nerves cells in visual cortex respond to specific features of stimulus like shape angle etc; passed on to SUPERCELL CLUSTERS which analyze for complex patterns
parallel processing
processing many aspects of problem simultaneously; brain’s natural information processing for functions
gestalt
an organized whole; emphasizing tendency to integrate pieces into a meaningful whole
figure-ground
organization of visual fields into objects and background
grouping
perceptual tendency to organize stimuli into groups (proximity continuity closure emergence multistability)
depth perception
ability to see objects in 3D and judge distance
retinal disparity
brain composes image from 2 eyes; greater the disparity between 2 images the closer the object is
monocular cues
relative height relative size relative motion interposition linear perspective light/shadow texture
phi phenomenon
illusion of movement when 2+ adjacent lights blink on & off in quick succession
perceptual constancy
perceiving familiar objects as having consistent color despite illumination changing wavelengths reflected by object
shape constancy
neurons learn to reorganize objects from different angles despite shape change
perceptual adaptation
ability to adjust to changed sensory input
outer ear (pinna)
funnels sound waves to eardrum
eardrum
vibrates from vibrations in air
middle ear
3 small bones (hammer anvil stirrup)
cochlea
snail shaped tube in inner ear has small hairs lining it which shake when fluid moves
sensorineural hearing loss
caused by damage to cochlear receptor cells or auditory nerve (nerve deafness)
conduction hearing loss
hearing loss caused by damage to mechanical system
cochlear implant
device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes into cochlea
place theory
links pitch we hear with place on cochleas membrane stimulated (explains high frequencies)
frequency theory
rate of nerve impulses traveling up auditory nerve matches frequency of tone (100 sound waves/sec-> 100 pulses/sec)
volley principle
neurons alternate firing in rapid succession to achieve COMBINED frequency of 1000+ waves/sec
touch receptors
pressure cold warmth pain
pain
biological: nociceptors detect harmful chemicals, temps, pressure; phantom pains
psychological: attention, memories differ
social: expectations, empathy
gate control theory
spinal cord contains neurological “gate” that blocks/allows pain signals traveling up small nerve fibers and is closed by activity in large fibers (massage
taste sensations
sweet salty sour bitter umami/savory
kinesthesia
movement sense; system of sensing position & movement of body parts
vestibular sense
sense of body movement and position; enables balance
sensory interaction
senses influence each other and rely on each other (less taste when nose is clogged)
embodied cognition
influence of body sensations gestures and other states on cognitive preferences and judgements
McGurk Effect
visual perceptions can overpower auditory sensations
sense - location
vision - bottom, occipital lobe
hearing - middle, temporal lobe
taste - parietal lobe, above hearing
smell - amygdala, limbic system, behind eyes
kinesthesia/ vestibular - cerebellum
touch - somatosensory cortex, parietal
