quiz5 Flashcards
what is sensation
translating physical stimuli from the environment into a neurological signal
what is perception
interpreting the neurological signal as a conscious experience (recognition)
explain eye anatomy
- light comes in through the lens
- light this the back layer of eye (retina) which causes neural impulses to occur in rods and cones which then travels through optic nerve into brain
what is the fovea
focus point of eye
what are the two types of photoreceptors
sensory receptors in the eye, rods and cones
what are the properties of rods
- use pigment rhodopsin
- located throughout retina (not fovea)
- high sensitivity for low level light
- used in night vision
what are the properties of cones
- uses pigment photopsin
- located at fovea
- involved in high activity (precise) vision
- only useful in well lit conditions
- color sensitive
- three types
1) short-blue
2) medium-green
3) long-red
what is the tectopulvinar visual pathway
- unconscious pathway
- retina -> tectum and superior colliculus in brainstem -> pulvinar nucleus of the thalamus -> parietal lobe
- “where” pathway
- responsible for rapid orienting
- more sensitive to info from periphery
- receives information from “M” ganglion cells (motion)
what is the geniculostriate visual pathway
- conscious pathway
- both “M” (motion) and “P” (fine details and color) ganglion cells project here
- retina -> lateral, geniculate nucleus of thalamus -> occipital lobe (striate cortex)
- “what” pathway
what are ganglion cells
retina’s output layer of cells, axons form the optic nerve running from the retina to brain
what is blindsight
the ability to see even when blind
-can still sense motion unconsciously in the tectopulvinar visual pathway
what is the cortical magnification factor
- visual space mapped onto the retina (retinotopic map)
- visual pace is mapped onto the cortex, wit magnification of information from the fovea
- more space dedicated to face on homunculus
- describes the millimeters of critical surface that are devoted to one degree of angle in the visual world
what is the blindspot
- area in the retina where there are no photoreceptors, the point at which all ganglion cell fibers are gathered together in a bundle to exit the eye as the optic nerve
- cannot perceive light
- with two eyes you will never perceive blindspot
- will never notice blindspot unless you look for it (brain processes rest of information)
what is cortical blindness
-people with blindsight have cortical blindness
-blindness caused by damage to the cortex not the eye
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what are the types of cortical blindness
hemianopia, quadratanopia, and scotoma
