2. Normal Development of Monocular Aspects of Vision

Question 1

at what age are VEPs just detectable at?

Answer 1

1 or 2 weeks of age

Question 2

when do VEPs start to get smaller in amplitude? why?

Answer 2

6 months of age

response becomes more complex

Question 3

the latency of VEPs steady decreases until the child is how old?

Answer 3

100 days, reaching 1/10 sec (same as adults)

Question 4

changes in VEP are dependent on the development of what?

Answer 4

development of the retina

Question 5

VEP shows a steady inc in VA that levels off around ___ months, then starts again at what age?

Answer 5

7 months

6-7 years of age

Question 6

in kittens, when is visual acuity mature at

Answer 6

3-4 months of age

Question 7

in kittens, at what age does CSF greatly increase from? until when?

Answer 7

greatly increases from 3-4 weeks until 12 weeks

Question 8

in humans, at what age does VEP CSF increase greatly from? until when?

Answer 8

increases greatly from a very insensitive 2.5 months until 6 months but still not at adult levels

Question 9

in cats, how does the CSF develop in 3-4 weeks? 4-5 weeks? 6-7 weeks?

Answer 9

3-4 weeks: cortex becomes active (VA very low)
4-5 weeks: improves rapidly (esp at lower freq)
6-7 weeks: starts to level out

this period is the critical period wehre cats can develop amblyopia

Question 10

in humans, what is the VEP VA at 2 months? 6 months?

Answer 10

2 months: 20/100

6 months: 20/40

Question 11

what did the MIT procedure tell us about grating acuity?

Answer 11

grating acuity develops as a function of mature (developmental delays), not age and experience

Question 12

what did the MIT procedure tell us about CSF in infants?

Answer 12

highly reduced for all spatial frequences in infants (100x less sensitive)

Question 13

what information does VEP tell us? PL?

Answer 13

VEP shows what information is traveling through the visual system
PL shows how well the infant actually sees and responds to their environment

Question 14

at what age do VEP and PL findings approach one another?

Answer 14

1-2 years of age

Question 15

what is the VA for PL at 2 months? 6 months?

Answer 15

2 months: 20/400

6 months: 20/100

Question 16

why is landolt C a much more accurate measure for amblyopes?

Answer 16

bc reading letters requires position sense while gratings do not..position sense is what is affected in strabismic amblyopia

Question 17

at 4 weeks, an infant is _____ times less sensitive to light than an adult. and at 18 weeks they are ___ times less sensitive.
what age does light sensitivity approach adult levels?

Answer 17

4 weeks=25x
18 weeks=4x

2 years of age

Question 18

why does a 3 month old have a lightly higher photopic luminance sensitivity at short wavelengths?

Answer 18

due to differences in optical clarity

Question 19

why does a 3 month old have colors desaturated? esp in blue/green

Answer 19

reduced pattern vision

Question 20

at what age do almost all kids respond appropriately to changes in movement direction?

Answer 20

6-8 weeks

Question 21

at what age does orientation sense start? at what age does almost every kid have good recognition of chagnes of 30 deg or more?

Answer 21

ability starts at 4 weeks, and by 10 weeks have good recognition

Question 22

in macaque monkeys, when does contour integration (ability to pick our a different border or object among others) develop?

Answer 22

6 months then begins to show improvement from there