BIO 09 (part a) - Plasticity

Question 1

What is plasticity?

Answer 1

• Also referred to as neuroplasticity, this describes the brain’s tendency to change and adapt as a result of experience and new learning (both functionally and physically)
• This generally involves the growth of new connections
• There are two types of plasticity: structural plasticity and functional plasticity

Question 2

Describe plasticity in infancy

Answer 2

• The brain experiences a rapid growth in the number of synaptic connections it has, peaking at about 15,000 per neuron at 2-3 years of age
• This is about twice as many as there are in the adult brain

Question 3

Describe plasticity in childhood

Answer 3

By the end of the first year of life, the brain has more neurons than it will have when it is fully mature

Question 3

Describe plasticity as we age

Answer 3

• As we get older, the brain is ‘sculptured’ by our environment and experience. This helps the brain to adapt to the environment the baby is developing within
• Pathways and networks that are not used will die off, this is called synaptic pruning
• Any connections that are frequently used are strengthened

Question 4

Who conducted research into plasticity?

Answer 4

• Eleanor Maguire et al (2000)
• Bogdan Draganski et al (2006)

Question 5

What was the aim of Maguire et al’s study?

Answer 5

• Eleanor Maguire et al. (2000) studied the brains of London taxi drivers
• He wanted to investigate whether changes to the brain occurred in London taxi drivers

Question 6

What was the procedure of Maguire et al’s study?

Answer 6

• 16 male taxi drivers were compared to 50 male non-taxi drivers
• MRI scans were carried out to analyses the amount of grey matter in the brain (this contains the neural cell bodies)

Question 7

What were the findings of Maguire et al’s study?

Answer 7

• They found significantly more volume of grey matter in the posterior hippocampus than in a matched control group
• This part of the brain is associated with the development of spatial and navigational skills (called the posterior hippocampus) in humans and other animals
• As part of their training, London cabbies must take a complex test called ‘The Knowledge, which assesses their recall of the city streets and possible routes
• Maguire et al. found that this learning experience alters the structure of the taxi drivers’ brains
• They also found that the longer the taxi drivers had been in the job, the more pronounced was the structural difference (a positive correlation)
• The volume of the hippocampus positively correlated with time spent as a taxi driver

Question 8

What was the conclusion of Maguire et al’s study?

Answer 8

The requirement to learn ‘The Knowledge’ may have altered the structure of the taxi drivers’ brains

Question 9

Briefly describe Bogdan Draganski et al’s study

Answer 9

• Bogdan Draganski et al. (2006) who imaged the brains of medical students three months before and after their final exams
• Learning-induced changes were seen to have occurred in the posterior hippocampus and the parietal cortex presumably as a result of the learning

Question 10

What case study supports the idea of plasticity?

Answer 10

The case study of EB

Question 11

Who was EB?

Answer 11

• EB was a young boy who underwent a left hemispherectomy at age 2.5 to remove a tumour
• The left hemisphere normally controls language, yet EB recovered language abilities
• Danelli et al. (2003) conducted a detailed longitudinal case study of EB
• They assessed his language development over time, including standardised tests and brain scans
• They found that the right hemisphere had taken over language functions
• By age 9, EB had near-normal language abilities
• fMRI scans showed significant right hemisphere activation during language tasks

Question 12

What was concluded about the case study of EB?

Answer 12

• Demonstrates the brain’s ability to reorganise (plasticity), especially in early childhood
• Highlights the adaptive capacity of the right hemisphere to take on functions typically controlled by the left

Question 13

What are the strengths and weaknesses of the case study of EB?

Answer 13

• ✅ Strength: Real-life evidence for neuroplasticity and recovery of function
• ❌ Limitation: Single case study – may not generalise to all individuals or adults