unit 6 - sensation & perception Flashcards
sensation
the process by which our sensory receptors and nervous system recieve and represent stimulus energies from our environment
(ex. sight, smell, touch)
perception
the process of selecting, organizing, and interperting sensory information, which enables us to recognize meaningful objects and events
bottom-up processing
a message sent from your senses to your brain
top-down processing
your brain telling your senses what was just experienced
psychophysics
the study of the relationship between physical characteristics of stimuli and our pyschological experience with them
absolute threshold
detect stimuli
- the minimum stimulation needed to detect a particular stimulus 50% of the time
- ex. volume in a car
difference threshold
detect a difference in stimuli
- the minimum difference between two stimuli required for detection 50% of the time
- (just noticiable different - jnd)
subliminal threshold
can’t detect stimuli
- when stimuli are below a person’s absolute threshold
- ex. happening not aware
weber’s law
states that two stimuli need to differ by a certain difference, and not a certain amount to be percieved as different
signal detection theory
a person’s absolute threshold can change depending on the situation they are in
sensory adaption
when you continuously are stimulated by the same stimuli you will stop realizing the stimulation
transduction
the transformation of stimulus energy into neural impulses
phototransduction
the specific transfer of light enerrgy into neural impulses that the brain can understand (vision)
wavelength of lightwave
(aka: length between waves)
- determines the hue (color) of light
- (large wavelength = red; small wavelength = blue/violet)
amplitude of a lightwave
(aka: size of wave)
- related to the brightness of the light
- (high intensity = bright; low intensity = dull)
cornea
transparent tissue where light enters the eye
iris
muscle that expands and contrasts to
pupil
- round opening in the center of your eye
- colored tissue that makes “eye color”
lens
focuses the light rays on the retina
retina
contains sensory receptors that process visual information and sends it to the brain
accommodation
the process by which the eye’s lens changes shape to help focus near or far objects on the retina
bipolar cells
goes from bipolar cells to ganglion cells
ganglion cells
comes from bipolar cells
fovea
central point in the retina around which the eyes cones cluster
optic nerve
- carries neural impulses from the eye to the brain
- creates blind spots
thalamus
recieves information from the senses (except smell) and routes it to the brain to figure out what is going on
(sensory switchboard)
occipital lobe
(back head)
visual function (vision)
blindspot
a break in the visual field
nearsighted
if you can see near objects but far objects are blurry
farsighted
if you can see far objects but near objects are blurry
rods & cones
- rods/cones transduce light to color and brightness
- you have more rods than cones
- cones in the center of the retina, rods in the periphery
- cones see in color, rods don’t
- rods see in the dark, cones don’t
feature detectors
nerve cells in the visual cortex respond to specific features, such as edges, angles, and movement.
shape detectors
specific combinations of temporal lobe activity occur as people look at different important objects.
parallel processing
- processing of several aspects of the stimulus simultaneously
- the brain divides a visual scene into sub-divisions such as color, depth, form, and movement.
young-helmoltz trichomatic theory
- states that there are cones for: blue, green, and red.
- every other color you can see is a combination of those.
subtraction of colors
- paints/pigments
- three primary colors: red, blue, yellow
- when you combine paints you subtract wavelength, so you end up with black.
addition of colors
- when dealing with light the three primary colors are: blue, red, and green.
- when you mix light you add wavelength so when all are mixed together you end up with white.
color blindness
- genetic disorder in which people are blind to green or red colors.
- this supports the trichromatic theory.
opponent process theory
process that four colors are seen by the ganglion cells combined in pairs of red-green, blue-yellow, and black-white
color constancy
- color of an object remains the same under different illuminations
- however, when context changes the color of an object may look different
sound waves
composed of compression and rarefaction of air molecules
acoustical transduction
conversion of sound waves into neural impulses in the hair cells of the inner ear
wavelength of sound waves
the distance from the peak of one wave to the peak of the next determines the pitch
amplitude of sound waves
- amount of energy in a wave, determined by the amplitude, relates to the perceived loudness
- the taller the wave the louder the sound.