Sensation and Perception Flashcards
What is sensation
Transduction of real-world input into electro-chemical response
raw sensory inputs
What is perception
majroity of what the nervous system actually does
interpretation of raw sensory inputs
What does the somatosensory system encode and what are they
Modality = types of touch
Location = ending location of a stimulus
Intensity = smallest change that will activate a receptor
Duration = onset and offset of a stimulus
what kind of modalities do mechanoreceptors encode?
flutter
stretch
pressure
What are nocireceptors responsible for and what are they activated by
pain information
activated by an excessively intense stimulus in another modality (high temps, intense pressure)
What is a receptive field and what changes its size?
real-world space encoded by a particular receptor
the size of a receptor field is systematic for what it is behaviorally meaningful for in that particular region of the body
fingers do fine-grained information and therefore their receptive fields are small
How do we measure receptive fields in the somatosensory system?
two-point discrimination
take a compass or caliper, and change the distance between the two points
if these two points span between two receptive fields, the person will feel two points of contact
if these two points are in the same receptive field, the person will only feel one point of contact
Do we get an AP if the stimulus is consistent?
NO (called receptor adaptation)
a chronic, unchanging stimulus results in a decrease in firing rate of AP
Slowly-adapting receptors
begin firing at onset of stimulus and keep firing as long as the stimulus is present
rapidly adapting receptors
begin firing at the onset of a stimulus, but stop firing during a “steady state” event
Why are rapidly and slowly adapting receptors important?
allow us to be aware of certain stimuli and unaware of other stimuli
don’t want to be aware of something as constant as our clothes touching us
Meissner Corpuscles
rapidly adapting
type 1 (small receptive fields, superficial)
important for fine grained info
Pacinian Corpuscles
rapidly adapting
type 2 (large receptive fields, deep)
important for deeper pressure/stimulus
Merkel discs
slowly adapting
type 1 (small receptive fields, superficial)
important for fine grained info
ruffini endings
slowly adapting
type 2 (large receptive fields, deep)
important for deeper pressure/stimulus
