Visual Development and Neural Plasticity Flashcards
1
Q
synaptic plasticity
A
- ability of a synapse between two neurons to change in strength or effectiveness
- visual/sensory experience vs. genetic/intrinsic programming vs. intrinsic development cues and rules
- is the adult brain plastic?
2
Q
binocular interaction
A
-first site is primary visual cortex
3
Q
proline injection
A
- revealed the pattern of ocular dominance in cortex in adult
- not one in babies
- at various time points shows none at 2 weeks and present by 13 weeks
- when LGN afferents first invade cortex, they come in unsegregated according to eye of origin
4
Q
congenital cataract
A
- removed too late- after 10- functionally blind
- adult was ok
- amblyopia
- something special between early childhood and adulthood
- psychologists had known about learning other behaviors- language
5
Q
OD scale
A
- 1 is contra
- 4 is binocular
- 7 is ipsi
- if you deprive one side it won’t develop correctly
- the good eye takes over territory normally occupied by the other eye
- remodeling happens in cats too
- occlusion for as little as 6-7 days has an effect
6
Q
monocular deprivation at different times
A
- led to discovery of a critical period
- 1 year better than 2 or 10 weeks, 6 years had little effect
7
Q
binocular deprivation
A
- extends critical period
- leads to few binocular sides
- issue isn’t disuse it’s competition
8
Q
critical period
A
- language and speech
- sensory-motor and social
- as well as eyes
9
Q
strabismus
A
- peripheral disorder
- involves extraocular muscles
- causing misalignment of the two eyes, preventing proper binocular vision
- leads to amblyopia in younger children
10
Q
amblyopia
A
- lazy eye
- central disorder resulting from an imbalance or lack of visual coordination between the two eyes during development
- leads to poor vision or acuity in one eye compared to strong eye
- can also be caused by refractive errors and cataracts
11
Q
two distinct issues
A
- must correct source of binocular balance to address amblyopia
- normal requires match of strength of input from each eye and a coordination of inputs- seeing the same thing at the same time
12
Q
binocular vision
A
- proper convergence of two eyes and matching refraction and image quality
- allows nascent binocular cortical cells to receive conjoint, synchronous activity arising form the viewing of the same object in each eye
- why- synaptic pruning
13
Q
steriopsis
A
- depth vision
- poor for both binocular deprivation and strabismus
14
Q
alternation
A
- other result of strabismus- each eye on in alternating fashion so strength is near same
- no binocular vision
- amblyopia gives same diagram as oppression- lose that one eye
- need to pick one way in order to avoid diplopia
15
Q
Hebb’s hypothesis
A
- any two cells that are repeatedly active at the same time will become associated- one activity facilitates activity in the other
- axon strengthening
