Neuroplasticity

Question 1

Define neuroplasticity

Answer 1

Neuroplasticity refers to the brains ability to alter its own structure following changes within the body or external environment

• minute changes - creation of new dendrites after learning
• big changes - stroke kills a section of the brain - another section takes on its function

Question 2

Define dendritic branching

Answer 2

process of neurons connecting with other neurons, dendrites of neurons grow in number and connect with other

Question 3

Define neural pruning

Answer 3

process of weakening and removing synapses that are no longer needed when under-stimulated as a way for the brain to improve the efficiency and functioning of neural networks.

Question 4

define long term potentiation

Answer 4

Long term potentiation is the process of synapses becoming stronger through repeated use

• leads to greater level of response - longer depolarisation periods —> protein synthesis and gene expression* that build new dendrite branches (dendritic branching)
• stronger synapses + dendrites, growth and permanency

Question 5

Maguire et al

Answer 5

Aim: to investigate whether brains of London taxi drivers would be somehow different as a result of their exceptional knowledge of the city
- quasi experiment
- correlational data
- single blind
London taxi drivers have to know every street in London (mental map)

Participants were:

• 16 right-handed male taxi drivers
• 50 right handed males (non-taxi drivers) taken from database - pre-existing

Results:

• posterior hippocampi were significantly larger in taxi drivers
• however, anterior hippocampi were significantly smaller
• right posterior hippocampi correlated with amount of time spent as a taxi driver

Conclusions: Posterior hippocampi must be involved with spacial navigation

Question 6

Draganski et al

Answer 6

Aim: to investigate whether human brains can change structure in response to environmental demands

Participants: self-selected volunteers with no prior juggling experience

Procedure:

• Sample randomly divided into 2 groups
• Brain scans done of each participant
• Jugglers spent 3 months learning a juggling routine then underwent brain scans
• Jugglers then spent next 3 months not practising, undergoing brain scans once again
• Non-jugglers never practised

Results:

• no differences in brain structure between jugglers and non jugglers prior to the experiment
• After 3 months of practise jugglers had significantly more grey matter in the mid-temporal area of the cortex of both hemispheres
• After 3 months of no practise, differences decreased, however jugglers still had more grey matter

Conclusion:

• human brains can change structure in response to environmental demands (learning and lack of practise)
• dendritic branching + neural pruning

Evaluation:

• ecological validity, affected by real world context + unnatural motivation of MRI scan
• internal validity, affected by how often prtps. practice, social desirability bias
• repeatable
• vast applications