Final - Lecture 20

Front 1

Do humans ahve the biggest brain/body ratio?

Back 1

No

Front 2

What accounts for the special size of the human brain?

Back 2

RElative to other naimals with the same body size, our brains are exceptionally large (encephalization); our brains ahve a much longer susceptibility to environmental influences (prolonged learning)

Front 3

What animals have the shortest and longest gestation periods?

Back 3

Shorts: Opossum (12-13 days); Longest: Asiatic elephant (608 days)

Front 4

Are humans more advanced at birthday than other animals?

Back 4

No

Front 5

What is "neotony?"

Back 5

Human characteristic of very slow development and retention of juvenile features

Front 6

What is strabismus?

Back 6

Squint; a misalignment of the eyes typically due to a weakness in one or another extra-ocular muscles; seen in about 4% of childre; half of children with untreated strabismus go on to develop amblyopia (a visual impairment without any physical problem in the eye)

Front 7

What is the problem with patching the good eye to cure strabismus by forcing the child to see out of the bad eye?

Back 7

The good eye can become nearly blind

Front 8

Who are Hubel and Wiesel?

Back 8

Worked as postdoctors under Stephen Kuffler; aware of the interesting problem of patching as a treatment for strabismus ~ Hubel developed Tungsten electrode which allowed extracellular recording of action potentials in cortical neurons & used that to test cells in V1 ~ ocular dominance historgram showed that equal likelihood that a cortical neuron would be activated by the ipsi and the contralateral eye

Front 9

Can patching of the stronger eye after the critical period redress ocular dominance imbalance?

Back 9

No

Front 10

What is the effect of patching both eyes during development?

Back 10

No effect on odcs, but profound effect on vision

Front 11

How was the shift in odcs labeled?

Back 11

Transynaptic labeling with radioactive proline

Front 12

Why does patching (monocular deprivation) cause ocular dominance columns for the open eye to widen?

Back 12

Because at the time the visual cortex is susceptble to sensory deprivation its odcs are not fully formed; there appears to be considerable overlap between the regions occupied by the thalamocortical axons drive by the two eyes; end of hte critical period coincides with complete segregation of odcs & raises the possibility that only when axons from the two eyes coincide can experience affect outcome

Front 13

What is the result of alternating eye patching (alternating occlusion)?

Back 13

Wipes out binocular neurons in cortex

Front 14

What is Hebb's Postulate?

Back 14

Neurons that "fire together wire together;" neurons that "fire out of synch, lose their link"

Front 15

Why might cells from adjacent regions of the retina fire together?

Back 15

Spontaneous waves of activity in the retina ~ even before opening the eye, retinal ganglion cells in one retina are more likely to be synchronously firing than retinal ganglion cells serving the same part of the visual field in the other retina

Front 16

WHat parts of the nervous system have extra axonal branches that are pruned during development?

Back 16

Neuromuscular junction, cerebellum, retinogeniculate, autonomic ganglia

Front 17

Who was Heinroth?

Back 17

First to describe imprinting in 1911 when studying the differences between ducklings and goslings

Front 18

What did HF Harlow do?

Back 18

TEsted the effects of no mother or surrogate mothers on newborn monkeys; results suggested that in the absence of a normal mother, behavior later is adversely affected