Sensation and Perception Flashcards
compare sensation to perception
looking out the window sensation is the wavelengths hitting the retina and perception is organizing the colors and shapes to recognize a tree
what are the 4 properties that sensory receptors communicate to the CNS
modality
location
intensity
duration
exteroceptors vs interoceptors
stimuli of outside world vs stimuli inside the body
olfactory and gustatory receptors are chemoreceptors , how do they differ
olfactory - respond to volatile chemicals in the air and are sensitive to many many different compounds
gustatory - respond to chemicals in food and only have a limited amount of tastes
mechanoreceptors are responsible for
touch
what are proprioceptors
give a sense of the relative position of the parts of our body in space
what is the difference between proximal and distal stimuli
proximal - what a sensory receptor detects , ie lightwaves hitting your eye
distal - the object that causes those signals , ie the bark and leave that absorb and emit certain wavelengths
what is the absolute threshold
what is crucial to remember about this
level of intensity a stimulus must have to be picked up by sensory neurons, usually about 50%
yes or no - if doesn’t reach threshold then nothing happened at all
can a stimulis be above the threshold of perception while still remain below the threshold of conscious perception
yes
what is the just noticeable difference
exactly what it sounds like
I can tell the difference between a 5 and 15 lb weight but not a 5 and 10lb
what is psychophysical discrimination testing
test whether subjects can tell the difference between two stimuli
ex. can you tell the difference between 5 and 10lb weight
what is webers law
any given sensory input the just noticeable difference will be a constant proportion of the original
I can tell the difference between 10 and 11 lb weight which is 10% so I can tell the difference between 100 and 110 lb weight
where does webers law break down
at the extremes
ex can’t tell the difference between a 10000 and 11000lb weight
what is signal detection theory
brain is filtering through input to identify signals that need responding to
use the bear analogy to represent all the terms in signal detection theory
bear is actually present and we perceive it as present and run - hit
bear is there and we don’t notice - miss
we think bear is there but it isn’t - false alarm
we dont think bear is there and its not - correct rejection
what is sensory adaptation
ability to get used to stimuli
ie don’t notice the shirt on your back
what are the two different types of receptors in regards to sensory adaptation
phasic - quick response to stimulus then stop ex.hair follicles
tonic - adapt slowly and continue to send action potentials as long as stimulus is present – think slowly sip gin and TONIC
difference between top down and bottom up processing
listening to a song
start off with perceiving the beat of the music and processing it to be a certain song - bottom up
then once you know the song your brain knows what should be coming next - top down
how can our sensory processing cause someone to not find an object thats right in front of you
top down - skim over it but you don’t expect it to be there
what are gestalt principles
how we perceive things as whole
best to just look at examples of these