Other sense Flashcards
sound stimuli door
changes in air pressure door displacement of molecules
human ear sensitive for freq from .. to ..
20 and 20000 Hz
waves with fixed endpoints
like guitar. have different frequencies than normal sound waves!
they have a fundamental frequency (f0) and its harmonics. The harmonics are f 0 multiplied by an integer
values from 1 to ∞.
fundamental frequency f0
has the most energetic component, most power.
outer ear
collect and focus sound energy
middle ear hoe gaat de wave
energy hits eardrum (tympanic membrane) -> malleus -> incus -> stapes -> oval window -> cochlea
welke van windows zit boven en welke onder
oval window, daaronder round window
andere naam voor eardrum
tympanic membrane
internal ear
cochlea
cochlea consists of
3 chambers filled with fluids and basilar membrane met stereocilia
how does the sound travel through the cochlea
stapes moves -> fluids move -> stereocilia move -> membranes of hair cells get depolarized
tonotopic organization in cochlea
high frequencies will activate hair cells in the beginning (cochlear base) and low frequencies will activate hair cells at the end (cochlear apex)
how does the signal travel through the peripheral auditory pathway
cochlear nerve -> cochlear nucleus (medulla) -> superior olivary complex (L en R samenkomen, brainstem) -> nucleus of lateral lemniscus -> inferior colliculi (orientation towards sound, midbrain) -> medial geniculate nucleus (thalamus) -> primary auditory cortex A1 -> evt secondary auditory cortex A2
evolutionairy important sounds…
occupy a larger brain area
Generally, auditory stimuli are processed in both
hemispheres, but
- A small preference for contralateral sounds
- Speech sounds predominantly in the left hemisphere (music more in the right hemisphere!).
3 qualities of sound
- loudness
- pitch
- timber (quality)
loudness
sound intensity: waves. expressed in dB. (not defined by physical processes -> bv wanneer twee mensen praten is het niet opeens harder dan 1 persoon hoewel er wel meer waves zijn).
pitch
tones: frequency. ook niet alleen fysiek: want harmonics worden ervaren als dezelfde pitch als fundamental frequency.
pitch. The pitch you
experience is that of the
largest common divisor.
oke
pitch and frequency are different places in the brain, waar?
pure tones: primary auditory cortex
frequency: belt
timbre
quality, hierdoor kunnen differentieren tussen twee geluiden met dezelfde loudness and pitch. dit hoor je ook op een gitaar
kleiner dan 3 kHz
interaural time difference (paths are of different lenghts)
groter dan 3 kHz
interaural intensity difference (door de grote frequency krijg je een soort schaduw over het ene oor van de andere frequencies)
waardoor interaural time difference en welke brain structure merkt dit
sound travels slow -> difference is goed te merken tussen twee plekken (zoals de oren) -> medial superior olive is coincidence detector.
waardoor interaural intensity difference
hoofd is obstakel voor high frequencies (low freq travels further…) -> sounds from R come to lateral superior olive R (LSO) -> inhibits LSO on left -> ALLEEN signal van R, niet meer van links naar hogere centres.
wat gebeurt er in de inferior colliculus
the two systems doing this (time and intensity) meet in the inferior colliculi to know where the sound comes from
cutaneous system
Perception of touch, vibrations, pressure and
tension. Tactile information.
nociceptive system
pain and temperature
proprioceptive
self movement and body position
vestibular system
Perception of acceleration and deceleration of
the body, balance, position of the head in space
Skin: Each receptor is specialized to a
different category of mechanical force.
The quality of the perception (what, where)
depends on the receptors being stimulated and
where they project to in the brain.
oke
meissner corpuscles
Sensitive to low frequency
vibrations. Small receptive
fields
pacinian corpusles
Sensitive to high frequency
vibrations. Large receptive
fields
rufini endings
Respond to skin stretch
Some areas, such as
the fingertips, have a
high density of
receptors (with small
receptive fields; 1 2
mm).
Other areas, such as
the forearm, have less
receptors with larger
receptive fields
(several
oke
hoe gaat een sensory stimuli naar de hersenen?
naar dorsal root ganglia! -> ventral posterior nuclear complex in thalamus -> the primary somatosensory cortex S1
3a -
proprioception
3b & 1
cutaneous stimuli
2
tactile + proprioception
free nerve endings
proprioceptors -> pain
pain
Pain is not a property of an object but is a
mental construct. The perception of pain is
entirely created by the brain (just as perception
in other sensory systems is also largely a
creation of the brain!
olfactory epithelium
bevat receptors die alleen maar 1 receptor eiwit produceren
Most odors contains different types of odor
molecules. Each different odor molecule can
bind to a specific receptor. Smelling an odor is
thus the combination of different odor
molecules to different receptors (there are, for
example, no specific rose receptors or the smell
of roses).
oke
The axons of these receptor neurons form the
olfactory nerve that projects to the olfactory
bulb.
oke
taste cells provide info about…
information about the identity, concentration
and hedonic quality of the substance
bitter
end
sweet
tip
sour and salty
sides (salty ook beetje in tip)
hoe gaat het signaal van taste
taste cells in tongue -> brainstem -> thalamus -> anterior insula met gustatory cortex
development of primary visual cortex…
has a critical window
hoe is deze plasticiteit voor somatosensory cortex
die kan wel goed aanpassen!
tonotopic organization occurs in the whole pathway
oke
placebo effect
opiate receptors
