Neuro ch 7 vision

steve became depressed as his neurological condition

impairs his ability to perceive faces

t or f steve was able to get through elementary school by memorizing voices and mannerisms of the small amount of people he knew

t

steve’s disorder is called

prosopagnosia

prosopagnosia translates to

face ignorance

t or f patients with prosopagnosia use things like voice, gait, or hair to recognize others

t

t or f syratefies to recognizeothers when u have prosopagnosia develop later on

t

t or f its uncertain how many people struggle from prosopagnosia

t

1 in ____ people may suffer from prosopagnosia

50

prosopagnosia helps us understand

that visual processing involves many subcomponents

retina

neural structure at the back of the eye where visual perception happens

t or f most of the outer eye has the goal of focusing light onto the retina

t

pupil

opening in eye that allows light to get in based on its contraction or relaxation

size of pupil is controlled by the contraction or relaxation of 

iris

iris

structure that contracts/relaxes and surrounds pupil

t or f the iris is pigmented so it determines eye color

t

1

pupil

2

iris

3

sclera

t or f pupil and iris are 2 most distinct feature of human eye

t

sclera

white part that surrounds iris

pupil and iris are a human obsession because

larger than other animals, sclera shows, we see where others are looking

main function of iris is to

control pupil size allowing control over amount of light entering

t or f the light from pupil/iris is sent to back of eye by lens to the retina

t

retina sends about _____ bits of information per second to the brain

10,000,000

to see your eye needs to transfer _____ into _______ 
(like action potential or neurotransmitters)

photons, signals brain can understandp

photons

particles of light

after photons are turned into signals, signals _______ areas in brainn to create a _______ scene

activate, visual

conversion of photons to signals happen int

retina

photoreceptor cells

contain (light absorbing molecule) Retinal that changes shape when photon collides with it

t or f shape change in retinal lead signals to travel from photoreceptor cells to other cells in retina and eventually the brain

t

2 types of photoreceptor cells

rods and cones

cones see ________

color vision

rods see _________

black and white visiont

t or f rods are only useful in dim light

t

t or f cones can adapt to greater illumination and continue sending info about photons theyre absorbing

t

t or f we only use cones during night

F

opsins

prompt absorption of different wavelengths of light 

retinal iin cones are connected to _____ (retinal in rods is too but only _)

opsins, 1

we have three different cone types, each sensitive to specific wavelenght:

short (blue), medium (green), long (Red)

_% of men have some formof color blindness

8

___% of women have some form of color blindness

0.5

t or f the most common colorblindness is to green and red light and genes that encode colors are found in X chromosome

t

guys have 1 X chromosome while women have 2, so color issue is likely to _____ out in women but _____ in men

cancel, persist

red-green color blindness occurs in cones sensitive to green light creating problems in

discriminating green hues causing yellow and green to appear red

t or f some species have only one cone and thus have minimal colorvision

t

dogs only have

2 cones

dogs vision can be compared to a human with

redgreen color blindness

carrots are rich in ________which is used to make _________ which is important to healthy vision

beta-carotene, vitamin A

cones are responsible for _______ color and for gpod visual __________

distinguishing, clarity

retina

t or f we instinctually turn towards light so it hits our fovea

t

fovea

area of highest cone density, found in retina, center of it contains no rods

photoreceptor cells pass sginal to

retinal ganglion cells

retinal ganglion cells

carry signal out of eye to brain

optic disc

where bundle of axons leave through

optic disc has no

rods or cones

t or f optic disc’s presence creates a blind spot in our visual field

t

the small blind spot from optic disc is hardly noticeable as your other eye…

fills in the missing information

fovea

optic disc

optic nerve

carries visual information back to brain

optic chiasm

optic nerve from one eye meets the other (junction), mix and travel into brain

t or f the visual fields are also processed by opposite sides of the brian

t

visual signal goesfrom optic nerves to _______

thalamus

there are _ thalami

2

thalami is made up of as many as -___ smaller nuclei

50

thalamus is called gatekeeper or relay because it acts as a

stopping point for neurons that travel to cortex

t or f senses stop at thalamus except for smells

t

thalamus is also involvedin 

analyzing and modifying info

Boerhaave observed a beggar with no skullcap, people would touch his cortex and B noticed

seeing stars/flashes of light, if more pressure blindness would follow, more pressure than that would result in loss of consciousness

Munk intentionally damaged parts of dogs occipital lobes, damage on small area resulted in ______, damage on large area resulted in ____

lack of recognition (no recall memories), blindness

psychic blindness

blind to importance of certain things

primary visual cortex

does intial processing for vision, goes herefollowing thalamus

primary visual cortex

primary visual cortex can dealwith

orientation, depth, color, motion

LM has blood clot in brain and said she couldn’t see _______

movement

akinetopsia

without seeing movement

middle temporal visual area

devoted to processing movement related visual info

fusiform face area

important for recognition of faces

middle temporal visual area

little light green circle

fusiform face area

t or f what we see isn’t a perfect replica

t

saccades

short back and forth darting movements helping to gather information rapidly

t or f sometimes brain tries to speed up analysis environment by drawing on past experience or inferences

t

t or f many animals (rats, kitchen,koalas) would be considered blind by human standards

t

t or f watching TV up close can make you blind

F

most common causes of blindness

untreated cataracts

cataracts

accumulation of protein in lens that impedes passage of light to retina

In US, blindness is most caused by

diabetes

t or f diabetes can cause blindness by impairing blood vessel supply to retina

t

t or f blind people often rely more on other senses (sens of touch)

t

those who can see can hear up to ____ syllables a second while the blind can hear up to ___ a second

10, 22

Underwood had retinal cancer resulting in both eyes being removed, he could understand his surroundings by making

clicking noises that bounce back to tell him sizes and where the objects are (echolocation)

echolocation

sonar system used by animals to perceive environment by emitting sounds and interpreting the echoes

t or f bats are blind

F

Tim had difficulty making eye contact, showed little recognition, and saw things without anything being there and nothing when there were things

visual anosognosia (Anton-Babinski syndrome)

anosognosia

without knowledge of disease

visual anosognosia - around only __ cases have been identified since the 1960s

30