Term
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Definition
monitors stimuli and these sensory events are transferred into changes in the cells membrane potential |
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Term
which lenghts of light spectrum can human see |
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Definition
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Term
how does colors disperse along the light spectrum we see |
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Definition
roy g biv 760-380nm red is 800nm violent is 400nm |
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Term
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Definition
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Term
how does brightness describe the light and what happens to light with decreasing brightness |
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Definition
its a measure of intensity of light. with decreasing brightness the color goes to brown then black |
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Term
what is saturation of light |
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Definition
the relative purity of the light |
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Term
what are three layers of eye |
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Definition
sclera pigment epithelium retina (goes from outside to inside) |
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Term
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Definition
-tough opaque outer coating of eye but at front of eye is is transparent -for protection |
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Term
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Definition
jerky movement of eyes when scanning a visual scene |
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Term
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Definition
movement eyes make to maintain an image of a moving object on the fovea |
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Term
how do you make you eyes move more slowly |
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Definition
looking at your finger while you moving it around |
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Term
what regulates the amount of light that enters the eye |
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Definition
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Term
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Definition
the changes in shape of the lens to focus on images of near or distant objects on the retina |
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Term
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Definition
similar to a sphincter muscle. circular band of muscle around the lens that is attached by ligaments and changes the shape of lens for accommodation |
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Term
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Definition
-contains blood vessels and nourishes photo receptors -contains melanin -at anterior has muscle groups which allow eye to adjusted for change in amount of light and diffraction and focal point |
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Term
why doesn't light just reflect all around inside eye |
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Definition
-the pigment in form of melanin which adsorbs light |
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Term
why do albinos have poor vision |
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Definition
light bounces around and lose ability to code topography of where light is on retina so its hard to tell where light is coming from |
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Term
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Definition
-receptor cells (rods and cones) of the retina |
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Term
how and what muscle is in iris |
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Definition
-smooth muscles layer on top of each other and increase the size of the pupil |
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Term
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Definition
dilator muscles sphincter muscles |
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Term
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Definition
-muscles radiate outwards like spokes on bicycle from the pupil -adrenergic -enlarges pupil |
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Term
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Definition
-concentric circles of muscle around pupil -cholinergic -shrinks pupli |
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Term
shape of lens when looking close or far away |
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Definition
lens is flat when looking far away |
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Term
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Definition
-accretion where by new tissue is added to outside |
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Term
how does way lens grow effect vision |
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Definition
new tissue just grows over old tissue and eventually lens can't get rid of waste or receive nutrients as well so this causes cataracts and decreases accommodation for distance. |
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Term
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Definition
rods and cones or also called photoreceptors |
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Term
how is light slowed through lens |
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Definition
-light is slowed through more dense material |
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Term
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Definition
measure of a material to slow light i.e. regular speed of light divided by slowed speed. the higher the number the slower the light is |
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Term
what part of eye makes up 80 percent of the refractory power |
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Definition
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Term
best way for lens to refract light more |
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Definition
-change angle of incidence so lens becomes more curved to maintain focal length if object gets very close |
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Term
how is farsightedness qualified in a person's eye |
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Definition
focal point is past the fovea |
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Term
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Definition
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Term
where is the blind spot in vision |
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Definition
produced by the optic disk |
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Term
why is there a blind spot in vision |
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Definition
there are no receptors in the optic disk |
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Term
what runs through the optic disk |
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Definition
-where the axons conveying visual info gather together and leave the eye through the optic nerve -emergence of 2nd cranial nerve -blood vessels coming in and out |
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Term
most prevalent in the central retina and fovea |
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Definition
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Term
sensitive to moderate to high levels of light |
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Definition
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Term
provide information about hue |
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Definition
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Term
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Definition
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Term
most prevalent in the peripheral retina and not in fovea |
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Definition
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Term
sensitive to low levels of light |
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Definition
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Term
provide only monochromatic information |
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Definition
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Term
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Definition
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Term
structure of rods and cones |
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Definition
outer segment connected by a cilium to an inner segment which contains the nucleus |
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Term
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Definition
thin plates of membrane in the outer segment of rods and cones |
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Term
where is the photopigment found |
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Definition
in the membrane of the lamellae |
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Term
what is contained inside inner segment of rods and cones |
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Definition
nucleus ribosomes mitochondria |
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Term
what is the function of inner segment of rods and cones |
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Definition
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Term
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Definition
place of contact between photodetectors and bipolar cells |
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Term
what is best way to describe light when accounting f or how light gets into rods and cones |
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Definition
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Term
What word to write on exam for bonus |
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Definition
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Term
where are horizontal cells located |
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Definition
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Term
where are amacrine cells located |
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Definition
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Term
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Definition
transmit info in a direction parallel to the surface of the retina and combine messages from adjacent photoreceptors and outer processes of bipolar cells |
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Term
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Definition
transmit info in a direction parallel to the surface of the retina and combine messages from adjacent ganglion cells and inner processes of biopolar cells |
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Term
what makes up photopigment |
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Definition
opsin a protein and retinal a lipid |
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Term
layers of retinal circuitry |
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Definition
start:ganglion cell layer then:bipolar cell layer end:photoreceptor layer |
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Term
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Definition
-consists of rod opsin and retinal |
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Term
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Definition
-starts off bent (11-cis retinal) in the dark and the light straightens it out and it decomposes into rod opsin and retinal which produces the change in the membrane potential of the photoreceptor |
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Term
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Definition
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Term
is there action potential for rods and cones |
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Definition
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Term
how is potential described for retinal circuitry |
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Definition
continuous change in the difference in outer segment and synaptic terminal |
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Term
describe change in electric potential in rod |
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Definition
-wall of inner segment has na-k pump -na enters outer segment in the dark and pump maintain inner segment at -30mv (depolarization) then light closes na channel in outer segment so it goes to -70mv(hyper polarization) |
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Term
what is released in dark in rods and what is affect on the retinal circuitry |
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Definition
glutamate is released and has inhibitory effect on bipolar and excitatory on ganglion cell |
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Term
optic path out of ganglion cell |
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Definition
-cranial nerve 2 goes to the optic chiasm -and go down optic tract to synapse at the lateral geniculate nucleus in the thalamus -then axon goes to synapse at occipital cortex or the striate cortex |
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Term
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Definition
the pathway from the lateral geniculate nucleus to the primary visual cortex |
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Term
what is the function of retinal disparity |
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Definition
coding for depth and subtle differences in vision in each eye due to the overlap |
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Term
how does cranial nerve run out of retina on each eye i.e. what is wiring pattern |
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Definition
nasal side of right eye is for right visual field and crosses the optic chiasm nasal side of left eye is for left visual field and crosses the optic chiasm temporal side of right eye is for left visual field and doesn't cross temporal side of left eye is for right visual field and doesn't cross |
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Term
how does nervous system extract info |
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Definition
simple wiring pattern similar to the senses i.e. retinotopic or topographic configuration |
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Term
how does a person have bitemperal hemianopsia and what is it |
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Definition
severe optic chiasm and get tunnel vision i.e. periphery is gone |
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Term
what happens if you severe left optic tract after on chiasm |
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Definition
the right side of each eye's vision is cut off |
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Term
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Definition
plant microelectrode in a cell in vision pathway and shine light on retina and find what part of retina that cell is referring too |
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Term
why is vision more acute at in center of vision |
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Definition
there is only one ganglion cell devoted to one photoreceptor as opposed to multiple photoreceptors converging on one ganglion cell |
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Term
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Definition
on in response to light in center and off in surroundings |
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Term
off center receptive cell |
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Definition
off in response to light in center and on in surroundings |
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Term
what is the function of on/off cells in life |
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Definition
visual reflexes and not direct role in form perception |
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Term
the excitation and inhibition diagram of on center cells |
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Definition
photoreceptor (-) bipolar (+) ganglion |
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Term
the excitation and inhibition diagram of off center cells |
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Definition
photoreceptor (+) bipolar (+) ganglion |
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Term
how they learned about lateral inhibition initially |
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Definition
by way of the limulus which had large individual lens with single photo receptor i.e ommatidium. and when light is shown on one and output went up but with light on one and simultaneously on neighboring photodectors and output decreases |
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Term
how does lateral inhibition help mammals |
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Definition
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Term
what causes a gradient to form when there isn't technically one there |
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Definition
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Term
what is the nature and design of receptor cells in horizontal configuration |
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Definition
1-2-3-4-5-6-7 (with light shown on 3,4,5
3 4 5 excited with 3 and 5 being most excited 2 and 6 are most inhibited |
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Term
how is lateral geniculate nucleus arranged |
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Definition
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Term
which layers in lateral gen. nuc. do lower animals need to see |
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Definition
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Term
what can layer one and two in lat. gen nuc do |
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Definition
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Term
how does size of receptive field in thalamus differ from before and why |
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Definition
it is bigger due to convergence |
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Term
in cortex what format of light gives best response |
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Definition
gradual change in light to dark of linear arrays |
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Term
which layers in cortex respond monocularly |
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Definition
layer 4 and other 5 layers responds binocular |
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Term
how do hyper columns respond |
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Definition
particular place in space to a line with an orientation |
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Term
layers 1 and two prefer high or low spatial frequency |
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Definition
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Term
how does visual angle work with spatial frequency |
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Definition
-as visual angle go down more info goes to the eye -spatial frequency is the number of bars you have per degree of visual angle |
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Term
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Definition
angle between two adjacent bars of light when they strike the retina |
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Term
what type of cells exist outside layer four of occipital lobe cortex |
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Definition
simple complex hypercomplex |
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Term
what does simple cells respond to. |
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Definition
-respond to circle of light but linear array of light is better like sine wave gradients |
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Term
what is pattern of response for simple |
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Definition
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Term
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Definition
one receptive field goes to one simple cell in cortex |
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Term
how is complex different from simple |
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Definition
it is bigger and doesn't have clear inhibitory zones and has coding for movement of bar of light |
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Term
how is complex cell wired |
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Definition
the convergence of receptive fields of multiple simple cells |
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Term
hyper complex inhibitory zones |
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Definition
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Term
what does hyper complex respond to |
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Definition
movement of light in particular direction |
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Term
visual association cortex has what two streams |
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Definition
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Term
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Definition
memory system of previous visual experiences. with stroke to ventral then u can't recognize dogs or faces size, shape, color, texture of objects |
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Term
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Definition
spatial relationship like where we are in space i.e. a cognitive map |
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