bottom-up processing
sensory analysis that starts at the entry level
top-down processing
we construct perceptions drawing on both sensations coming bottom up to the brain and experiences/expectations (top down)
psychophysics
relationships between physical characteristics of stimuli and our psychological experience with them
absolute thresholds
awareness of a faint stimuli (minimum stimulation necessary to detect a particular light, sound, pressure, taste, odor
50% of the time
subliminal stimulation
below the threshold stimuli (we detect stimuli only some of the time)
increases with size of stimuli
weber’s law
for their difference to be perceptible, two stimuli must differ by a constant proportion (not a constant amount)
sensory adaptation
our diminishing sensitivity to an unchanging stimulus
(vision)
hue
dimension of color that is determined by wavelength of light
(vision)
intensity
amount of energy in a light wave (determined by amplitude)
(vision)
eye
(vision)
retina
rods (black, white, gray, dim light)
cones (near center of retina; fine detail and color)
(vision)
optic nerve
carries neural impulse from eye to brain
(vision)
blind spot
where optic nerve is leaving eye (no receptors here)
(vision)
fovea
central point in retina (lots of cones)
(vision)
feature detectors
nerve cells in the brain that respond to specific features of a stimulus (shape, angle, movement)
(vision)
parallel processing
doing many things at once
color, movement, form, depth
(vision)
young-helmholtz trichromatic (three-color) theory
theory that retina contains three different color receptors (red, blue, green)
(vision)
opponent-process theory
theory that opposing retinal processes enable color vision
hearing
sound waves (air pressure waves)
(hearing)
frequency
number of complete wavelengths that pass a point per time unit
(hearing)
pitch
a tone’s experienced highness or lowness (depends on frequency)
(hearing)
middle ear
transmits eardrum’s vibrations through a piston made of three small bones (hammer, anvil, stirrup)
(hearing)
cochlea
touch
- other skin sensations are variations of pressure, warmth, cold, pain