Ch. 4 - Sensation and Perception Flashcards
sensation
the activation of the sense organs
-physical response
perception
how stimuli are interpreted
-psychological response
stimulus
any passing source of physical energy that produces a response in a sense organ
psychophysics
study of the relationship b/w the actual physical aspects of a stimulus and our psychological experience of that stimulus
absolute threshold
lowest intensity of a stimulus that an organism can detect
difference threshold
smallest level of added or reduced stimulation required to sense that a change in stimulation has occurred
weber’s law
a just noticeable difference is a constant proportion of the intensity of an initial stimulus
adaptation
an adjustment in sensory capacity after prolonged exposure to unchanging stimuli
light
the physical energy that stimulates the eye
how is light measured?
wavelengths
visual spectrum
range of wavelengths visible to the human eye
cornea
refracts/bends light to see it sharply
pupil
expands in size as it gets darker
retina
converts electromagnetic energy of light to electrical impulses for transmission to the brain
rods
highly sensitive to light
cones
responsible for sharp focus and color perception
rods play a key role in?
peripheral vision
peripheral vision
seeing objects outside the main center of focus
optic nerve
bundle of ganglion axons
feature detectors
specialized neurons that are activated only by visual stimuli having certain features, such as a shape or pattern
trichromatic theory of color vision
there are three kinds of cones in the retina, each of which responding to a specific range of wavelengths
opponent-process theory of color vision
receptor cells are linked in pairs, working in opposition to each other
sound localization
process by which we identify the direction from which a sound is coming
sound
movement of air molecules brought about by a source of vibration
eardrum
vibrates when sound waves hit it
cochlea
vibrates in response to sound
basilar membrane
covered with hair cells, when these cells bend from vibrations they send a message to the braina
frequency
number of wave cycles that occur in a second
pitch
makes sound seem high or low
amplitude
allows us to distinguish b/w loud and soft sounds
decibels
range of sound in terms of volume
place theory of hearing
diff areas of the basilar membrane are specialized to respond to diff sound frequencies
frequency theory of hearing
the entire basilar membrane acts as a microphone, vibrating as a whole in response to. a sound
echolocation
use of sound waves to determine where objects are
vestibular system
balance - responds to the pull of gravity and allows us to maintain our balance
semicircular canals
main structure of the vestibular system, consist of 3 tubes
otoliths
forward, backward, up or down
olfaction
human sense of smell
olfactory cells
receptor neurons of the nose
pheromones
chemicals that secrete into the environment that produce a social response from other members of the same species (sex, danger)
gustation
sense of taste
four basic stimulus qualities of taste
sweet, sour, salty, bitter
where are the receptor cells for taste?
the 10k taste buds on our tongue
RSDS
constant, intense pain that is out of proportion to any injury
what are the four skin senses
touch, pressure, temperature, pain
substance P
chemical released when a cell is damaged
gate control theory of pain
particular nerve receptors in the spinal cord lead to specific areas of the brain related to pain
synesthesia
the stimulation of one sensory system involuntarily leads to an additional sensory response
multimodal perception
the brain collects info from the individual sensory systems and integrates and coordinates it
gestalt laws of organization
closure, proximity, similarity, simplicity
closure
grouping elements to form enclosed or complete figures rather than open ones
proximity
elements that are closer together are viewed as grouped together
simplicity
we perceive patters in the most basic manner that we can
top down processing
perception is guided by higher level knowledge, experience, and motivations
bottom up processing
progression of recognizing and processing info from individual components of stimuli and moving to the perception of the whole
monocular cues
permit us to obtain a sense of depth and distance with just one eye
perceptual constancy
recognition that physical objects are consistent and do not vary even tho our sensory input of them changes
apparent movement
perception that a stationary object is moving
visual illusions
physical stimuli that consistently produce errors in perception
muller lyer illusion
assumptions thru visual stimuli that deceive us
subliminal perception
perception of messages about which we have no awareness
extrasensory perception
perception that does not involve our senses
where are the cones located?
fovea
top down perception is related to
higher level knowledge
binocular disparity
difference in images seen by the left eye and the right eye
lateral inhibitions
surrounding regions of white in a high contrast visual scene that serve to suppress the overall output of cells that correspond to specific regions in the visual field
