vision Flashcards
parts of the eye
cornea, pupil, iris, lens, retina, fovea, optic disc, optic nerve
what is the order of the visual sensory pattern?
receptors > thalamic relay nuclei (posterior part of the thalamus) > primary sensory cortex > secondary sensory cortex > association cortex
what is the wavelength of visible light?
400nm - 700nm
what’s the difference between rods and cone receptors?
rods are low light, cones are bright light
cornea
clear covering of the eye
pupil
the hole in the iris that lets light in
iris
opens and closes to allow more or less light in, changes the size of the pupil
lens
focuses light, bends to focus on near/far objects
retina
light sensitive part at the back of the eye that has neurons and photoreceptor cells
fovea
region in the center of the retina specialized for high accuracy of sensing
optic disc
AKA blind spot, there are no photoreceptors in this region
optic nerve
nerve that leads from the eye to the primary visual cortex
name the types of retinal neurons
bipolar cells, horizontal cells, amacrine cells, retinal ganglion cells
bipolar cells
takes input from photoreceptor cells
horizontal cells
links bipolar cells and ganglion cells
amacrine cells
links bipolar cells and ganglion cells
retinal ganglion cell
create connections from the eye to the optic nerve
describe visual transduction in the dark
opsin and retinal are put together to make photopigments, rod membrane becomes depolarized
describe visual transduction in light
photons change the shape of retina, retinal and opsin are separated, rods hyperpolarize
optic chiasm
collection of optic nerves from each eye
where does visual information go from the eyes?
the thalamus, specifically the lateral geniculate nucleus (LGN)
what is the lateral geniculate nucleus
Map of the retina. specific parts of the LGN map to parts of the retina. In the thalamus
what is the primary visual cortex of the occipital cortex called
striate cortex
what is the striate cortex and what lobe(s) do they lead to in the brain?
primary visual cortex that receives visual info from the eye. the two paths go to the parietal and temporal lobe
what does the dorsal visual stream do
identifies the “how.” how action is to be guided towards objects
what does the ventral visual stream do
identifies the “what.” what an object is
explain trichromatic theory
color vision is based on 3 primary colors: red, green, blue. we have cones sensitive to each color. limitation of this theory is the existence of yellow due to afterimages. red-green > blue-yellow
explain opponent process theory
explains the importance of opposing colors (red v green, blue v yellow).
explain sensation vs perception
sensation is taking in the stimuli surrounding you. perception is the interpretation your brain makes of the outer stimuli.
