Sensation and Perception Flashcards
transduction
process where signals are transformed into neural impulses
sensory adaptation
decreasing responsiveness to stimuli due to constant stimulation
sensory habituation
our perception of sensations is partially due to how focused on them
What are the steps of vision?
First, light is reflected off objects and gathered by the eye. and enters through the cornea and pupil. The iris dilates to let more light in and is focused by the lens, which inverts the image onto the retina. Then, transduction occurs where if enough rods and cones fire, they activated the bipolar cells, then the ganglion cells, then sends them to the appropriate areas in the thalamus. Then, they are sent to the occipital lobe of the brain to be interpreted.
cornea
protective covering of the eye and help focuses the light
iris
muscles that control the pupil
accomodation
light that enters the pupil is focused
rods
cells that respond to black and white; outnumber cones
cones
cells that respond to color; concentrated in fovea
optic chiasm
spot where nerves cross each other when impulses from each hemisphere of the brain interfere
trichromatic theory
theorizes that we have three types of cones in retina: blue, green and red. These combine to create all sorts of colors.
opponent-process theory
sensory receptors arranged in pairs: red/green, yellow/blue, black/white. If one sensor is stimulated, the other is inhibited from firing. Explains color blindness and afterimages.
amplitude
height of the wave and determines loudness of sound
frequency
length of the wave and determines pitch
How is sound collected by the ear?
waves travel down the ear canal until they reach the eardrum. Then, there are three sets of bones, the hammer, anvil and stirrup. The vibration of the eardrum is sent by these bones to the oval window, and to the cochlea which is filled with fluid. When the fluid moves, the hair cells connected to the organ of Corti move and transduction occurs.
place theory
hair cells in cochlea respond to different frequencies of sound based on where they are located in the cochlea. Some bend in response to high pitches and some to low.
frequency theory
lower tones are sensed by the rate at which cells fire; we sense pitch because the hair cells fire at different rates in the cochlea
conduction deafness
occurs when something goes wrong with the system of conducting sound to cochlea
sensorineural deafness
occurs when the hair cells in cochlea have been damaged by loud noise
gate-control theory
some pain messages have a higher priority than others. The gate swings open for higher priority message and swings shut for lower priority message
papillae
where taste buds are located
What are the five types of tastes?
sweet, salty, sour, bitter and umami (meat)
olfactory bulb
gathers messages from olfactory bulb cells and sends information to the brain. This is connected to the amygdala and hippocampus–responsible for emotion and memory.
vestibular sense
indicates how body is oriented in space as the fluid in ears move when your head changes
kinesthetic sense
gives feedback about position and orientation of specific body parts. Receptors in muscles and joints send information to brain about our limbs.
absolute threshold
smallest amount of stimulus we can detect
subliminal
anything below our absolute threshold
difference threshold
the smallest amount of stimulus needed for us to detect a change
Weber’s law
change is needed in proportion to the original intensity of stimulus
signal detection theory
investigates effects of distractions and interference we experience while perceiving the world. It takes into account how motivated we are to detect certain stimuli and what we expect to perceive.
false positive
when we think we perceive a stimulus that is not present
false negative
not perceiving a stimulus that is present
top-down processing
perceive by filling in gaps of what we sense
schemata
mental representation of how we expect the world to be
backmasking
supposed hidden messages in the background
bottom-up processing
we use only the features of object itself to build a complete perception. This is longer but more accurate
figure-ground relationship
figuring out what part is the object and what part is the background.
What are the Gestalt Rules?
- proximity
- similarity
- continuity
- closure
proximity
objects that are close together are more likely to be perceived as belonging in the same group
similarity
objects that are similar in appearance are more likely to be perceived as belonging in the same group
continuity
objects that form a continuous form are more likely to be perceived as belonging in the same group
closure
similar to top-down processing; objects that make up a recognizable image are more likely to be perceived as belong in the same group
size constancy
objects closer to our eyes will produce bigger images on our retina, but we take distance into account to estimate size
shape constancy
objects viewed from different angles will produce different shapes on retina, but we know shape remains constant
brightness constancy
we perceive objects as being a constant color even as the light reflecting off the object changes
stroboscopic effect
a series of still pictures presented at a certain speed will appear to be moving
phi phenomenon
a series of lightbulbs turned on and off at a particular rate will appear to be on moving light
autokinetic effect
if a spot of light is projected steadily onto the same place of a wall in a dark room, people will report that it is moving
monocular cues
depth cues that do not depend on having two eyes
linear perspective
drawing two lines that converge together to indicate that the lines continue on
relative size cue
objects closer are viewed as larger than objects in the distance
interposition cue
objects that block the view to other objects are closer to us
texture gradient
we can see details in texture close to us but not far away
shadowing
implying where light source is to imply depth and position
binocular cues
cues that depend on having two eyes
binocular disparity
because our eyes see at different angles, the closer the image is, the more disparity there is
convergence
as the object gets closer to our face, our eyes must move together to keep focused on object
