10: Brain Plasticity

Question 1

In what period is there rapid neuron growth in children?

Answer 1

Birth to 2 years old

Question 2

What determines if a synapse is pruned?

Answer 2

How much it’s used and how effective it is

Question 3

What is the main difference in the number of synapses in the visual cortex for blind people?

Answer 3

They have more synapses as they’re unable to prune out ineffective connections

Question 4

What is hebbian modification?

Answer 4

neurons that fire together, wire together

Neurons that fire out of sink lose their link

Question 5

When does pruning take place?

Answer 5

Around the age of 2 or 3

Question 6

What is a hemispherectomy?

Answer 6

Early removal of a brain hemisphere

Question 7

What is the effect of removing a brain hemisphere in early life?

Answer 7

There is little effect as the brain can adapt

Can be a few issues with movement

Question 8

How does plasticity change in adulthood?

Answer 8

The brain can still reorganise as a result of learning from experiance

Question 9

What are the two forms of plasticity in adulthood?

Answer 9

Use-dependent

Injury dependent

Question 10

What is the function of the homunculus?

Answer 10

Maping the body onto the sensory and motor cortexes

There is the same basic layout but a lot of individual differences in how it’s organised

Question 11

What was the study with musicians which explained why we have differences in body mapping?

Answer 11

String players had a larger and stronger brain activation to sensations on their fingers than a control group because they’ve been using them for so long. Their brain has adapted
Correlates with how early they learnt to play the instrument

Question 12

What was found about finger representations in blind people that used three fingers to read braille?

Answer 12

The mapping for the 3 fingers overlapped so they were unable to tell which finger the sensation was occuring on

Question 13

What adaptations are made in the brain’s of blind people?

Answer 13

More space donated to sound and touch instead of sight

Question 14

What evidence is there of cross modal activity in blind people?

Answer 14

When reading braille, the visual cortex was activated as it has taken over that function

Question 15

How do strokes demonstrate plasticity in the adult brain?

Answer 15

Motor and cognitive function can be recovered in the proceeding 3 months

Question 16

What is the mechanism of plasticity in adults?

Answer 16

Long term potentiation

Repeated neuron fire strengthens the synapse

Question 17

What was Draganski’s 2004 study into the brain and learning?

Answer 17

When adults spent 3 months learning to juggle, their hippocampus got bigger which shows how we can change our brain structure through experiance and learning

Question 18

How are stem cells linked to plasticity?

Answer 18

neural stem cells (Spinal cord) generate neural progenitor cells which create new neurons

New neurons take about 2 months to mature

Question 19

What things aid neurogenesis?

Answer 19

Enriched environment 
Exercize 
Learning
Diet
Antidepressants

Question 20

What things inhibit neurogenesis?

Answer 20

Stress
Ageing
Neurological disorders

Question 21

How is exercize linked to plasticity?

Answer 21

rats given a running wheel had improved cognition

Also seen in adults aged 65

Question 22

How does brain biology change as we age?

Answer 22

We lose white matter volume as we age, especially in the prefrontal cortex