8.4 Visual development

Question 1

After birth, there is a large increase in brain size. Why?

Answer 1

Elongation of axons, myelination and the development of synapses

Question 2

What happens when neurones stop dividing?

Answer 2

they migrate to their final positions and form synapses with other neurones

Question 3

axons increase in length from the retina to the…?

Answer 3

thalamus

Question 4

axons then develop from the thalamus to the…?

Answer 4

visual cortex in the occipital lobe

Question 5

what forms in the occipital lobe that allows the brain to create a 3D image?

Answer 5

alternating columns

Question 6

what is a critical period?

Answer 6

a period of time during postnatal development when the nervous system must obtain specific experiences to develop properly

Question 7

what did Hubel and Wiesel prove and what did they use?

Answer 7

they used monkeys and monocular deprivation to prove the critical period

Question 8

what does light deprivation do to the columns in the visual cortex?

Answer 8

they become narrower

Question 9

when one eye is deprived, why does the dendrites and synapses from the other eye take up more territory in the visual cortex?

Answer 9

where neurones overlap, only the synapses on axons receiving stimulation with fire causing the synapses from the light-deprived eye will be weakened and lost