Final Exam Study Guide Exam 3 Flashcards
the phantom limb phenomenon can include
sensations of pain, pressure, warmth, cold and itching
the frequency of vibration determines its
pitch
because the cochlea is filled with fluids, sounds transmitted through air,
must be transferred to a liquid medium
the lower frequencies of sound are encoded into pitch by means of
rate (frequency) coding
to determine the left-right localization of continuous low-pitched sounds, we use phase differences, which refers to
the time interval between the arrival at each ear of the oscillating sound wave
the ___ contains the sensory receptors of the semicircular canals
ampulla
ocular dominance refers to
alternate columns in the visual cortex responding to inputs from left and right eye
the semicircular canals are aligned
to the sagittal, transverse and horizontal planes in the head
dorsal stream of visua processing
is the “where” pathway
depth perception is achieved by
- monocular depth cues
- motion parallax
- retinal disparity
phototransduction refers to
converting light signals to electro-chemical signals
the 2 parts of the photopigment molecule are
opsin and retinal
optic nerves from each eye meet at the ___ where half of the axons cross to the opposite side of the brain
optic chiasm
centre-surround
shape of receptive field of ganglion cells
the first step in visual perception occurs when light
causes a photopigment to split into its 2 parts
retinal disparity helps us to recognize
depth
CO blobs of the striate cortex contain
color sensitive neurons
the ventral stream of visual association cortex recognizes
the identity and color of an object
Neurons in the ___ are colorblind, but can detect small contrasts between light and dark
magnocellular system
people who can not recognize common objects by sight but have good visual acuity have
visual agnosia
can’t recognize faces
prosopangnosia
akinetopsia is the inability to
perceive movement
most mammals such as dogs are ___, although humans are ___
dichromats; trichromats
what types of coding are involved in pitch?
frequency coding, place coding
___ lobes primarily process visual info; ___ lobes process auditory info.
occipital; temporal
has no hair follicles
glabrous skin
located in the middle layer of the retina and send info from the photoreceptors to the ganglion cells
bipolar cells
color is a property od
the brain
locate figure v. ground
detect movement
detect color
functions of vision
- light sensitive (not color)
- found in periphery of retina
- consists of stacked protein disks
rods
- color sensitive
- found mostly in fovea
- one continuous membrane
cones
are there more rods or cones?
rods (120 million to cones 6 million)
retinal circuitry orders
photoreceptor- 1st order
Bipolar cells- 2nd order
ganglion- 3rd order
bony pockets in the front of the skull
orbits
white tissue of the eye
sclera
mucous membrane that line the eyelid and protect the eye
conjuctiva
transparent outer covering of the eye that admits light
cornea
adjustable opening in the iris that regulates the amount of light that enters the eye
pupil
pigmented ring of muscles situated behind the cornea
iris
consist of a series of transparent, onion-like layers. Shape can be changed by contraction of ciliary muscles
lens
changes in the thickness of the lens, accomplished by the ciliary muscles, that focus images of near or distant objects on the retina
accommodation
the neural tissue and photoreceptive cells located on the inner surface of the posterior portion of the eye
retina
area of retina that mediates the most acute vision. contains mostly color-sensitive cones
fovea
location on the retina where fibers of ganglion cells exit the eye; responsible for the blind spot
optic disk
which channels are open and what is released in the dark?
Na+ channels open, glutamate released
__ breaks opsin and retinal apart
light
visual pathway within retina
photoreceptor-> bipolar cell -> ganglion cell
visual pathway beyond retina
ganglion cell-> through optic chiasm-> lateral geniculate nucleus (LGN) -> primary visual cortex-> extra striate areas
“ON-Cell”
light placed on center increases firing; light placed on surround decreases firing
- cells from retina terminate in LGN layers 1,2
- carry info on contrast and movement (color insensitive)
- carry input from “A” retinal ganglion (Y type) cells
magnocellular system
cells from the retina terminate in LGN layers 3-6
- carry info on fine detail, and R/G color
- carry input from “B” retinal ganglion cell (X type)
parvocellular system
cells from retina terminate between major layers in LGN
- carry info on B/Y color
- carry input from bistratified ganglion cells
koniocellular system
is the circular receptive field larger for magnocellular or parvocellular
magnocellular
cells respond to same orientation, adjacent cells are shifted by 10 degrees
orientation columns
visual neurons respond to
a sine wave grating: alternating patches of light and dark
which is mostly magnocellular input: dorsal or ventral
dorsal
“what an object is (analysis form)
ventral
equal mix of magnocellular and parvocellular output
ventral
monocular cues
- perspective
- relative retinal size
- apparent movement (motion parallax)
- occlusion
binocular cues
- retinal disparity (stereopsis): difference in images
form perception totally absent
apperceptive agnosia
disconnection between form recognition and some type of verbal/ associative output
associative agnosia
outer ear membrane
- pinna
- auditory canal (meatus)
- tympanic membrane
middle ear
- ossicles: malleus, incus, staoes
inner ear
cochlea
3 chambers of the cochlea
S. Vestibuli
S. media
S. tympani
___ hair cells touch the tectorial membrane directly
outer
___ hair cells do not touch the tectorial membrane, but the fluid moves them
inner
for high frequencies, vibration produces a travelling wave
near the base of basilar membrane
for moderate frequencies, vibration produces a travelling wave
near the apex of basilar membrane
different regions of the basilar membrane project to different areas of cortex:
tonotopic representation
support for place theory
- observations of travelling waves
- antibiotics
- cochlear implants
perception of Pitch: place coding
mid-to-high frequencies
perception of pitch: rate coding
low frequencies
coding of localization: low frequencies
phase or time of arrival coding
coding of localization: high frequencies
“sound shadows”/ timbre
perception of body’s position and posture
- provides feedback from muscles, joints and organs to control movement
proprioception
perception of body’s own movements
kinesthesia
sense modality that arises from receptors located within the inner organs of body
organic sense
precise touch, kinesthesia
- decussates at midbrain
Somatosensory pathway: lemniscal pathway
pain, temperature
- decussates at spinal cord
spinothalamic pathway
