Chapter 12 Flashcards
what is spatial orientation made up of?
linear motion, angular motion, tilt
what is linear motion?
translation (changes in x, y, z axis)
what is angular motion?
rotation
what axis is pitch?
y-axis
what axis is roll?
x-axis
what axis is yaw?
z-axis
what is tilt?
individuals orientation based on gravity (forward/backward)
what is vertigo?
the sensation of rotation/spinning
what does the vestibulo-ocular reflex do?
helps stabilize vision by counter-rotating the eyes when the vestibular system senses head movement
what is active sensing?
self-generated probing of the environment
what is graviception?
sense of the relative orientation of gravity based on the organism
why is graviception important?
words describe actions that define human movement (standup, sitdown, etc.)
what does the vestibular system do?
helps with balance, kinethesia, and visual clarity
how does the vestibular system help with visual clarity?
stabilizes the eyes during movement
what do semicircular canals sense?
angular acceleration/velocity
what do orolith organs sense?
linear acceleration/velocity and gravity
what position is the x-axis relative to an individual?
facing forward, through the nose
what position is the y-axis relative to an individual?
out the left ear
what position is the z-axis relative to an individual?
out the top of the head
how do hair cells operate as mechanical transducers?
responds to head movement through stereocilia deflection which changes the hair cell voltage and neurotransmitter release, which causes action potentials in the brain
what are ampulla?
swellings from semicircular canals that contain crista which senses angular motion
how does the direction and amplitude change during head rotation?
increases in one direction and decrease in the other, signaling the amplitude of direction
where are utricle and saccule located?
orolith organs
what do utricle and saccule sense?
gravity and linear acceleration
how does velocity storage affect rotation perception?
prolongs the rotational response after the signal is gone
how has translation perception been studied?
passively translating participants short distances while in a chair in the dark, then having them use a joystick to move the distance they believe they moved
what was found when studying translation perception?
participants were accurate in their movement and even correctly guessed the velocity without being asked
how has tilt perception been studied?
verbally asking participants to tilt a handheld probe a certain degree
what was found when studying tilt perception?
participants were accurate for angles less than 90 degrees
what is vection?
an illusory sense of self-motion caused by moving visual cues when one is not actually moving
what are examples of vection?
watching an imax movie, the car next to you moving, looking at water flow beneath you
why is it important for the vestibular system to distinguish between self-generated and externally-generated movements?
it’s essential for perceptual stability and accurate motor control
what is the purpose of efference copies?
helps the brain predict the expected sensory results of motor commands
how does the vestibular system contribute to autonomic functions?
regulates blood flow by informing the nervous system about the position and motion of the world
what is motion sickness?
a disagreement between the motion and orientation signals
where are multisensory visual and auditory cortexs found?
in several areas of the brain
how is vestibular information represented in cortex?
through multisensory visual and auditory cortexes that include sensory and motor signals
how can higher cognitive knowledge affect vestibular sensations?
by influencing how we perceive motion
what does vestibular dysfunction cause?
spatial disorientation, imbalance, motion sickness, cognitive problems, visual unclarity unless the head is held still
what is mal de debarquement syndrome?
boat disembarking sickness caused by unability to readapt
what does mal de debarquement syndrome cause?
spatial disorientation, imbalance, rocking for at least 1 month
what is menieres syndrome?
sudden dizziness, imbalance, spatial disorentation
what are additional symptoms of menieres syndrome?
tinnitus, hearing loss, ear pain, incapacitation
