Neuroplasticity - SAQ Flashcards
Neuroplasticity
The ability of the brain to change through the making and breaking of synaptic connections between neurons.
The different scales of neuroplasticity
Synaptic plasticity
Cortical remapping
Synaptic plasticity
The ability of the neuron to form new synaptic connections and break up the old ones.
Cortical remapping
The phenomenon where a certain brain area assumes the functions of another brain area due injury for example.
How does synaptic plasticity work?
Depends on the activity of neurons.
If two nearby neurons are frequently activated at the same time, a synaptic connection between them may gradually form.
Similarly, if two neurons are rarely activated together, the existing connection may gradually fall apart.
When neurons fire continually as a result of stimulation in the environment, the neurons sprout new dendrites – known as dendritic branching.
This increases the number of synapses available for the behaviour.
Study used for neuroplasticity
Maguire
When was Maguire?
2000
Aim of Maguire (2000)
to see whether the brains of London taxi drivers would be somehow different as a result of their exceptional knowledge of the city and the many hours that they spend behind the wheel navigating the streets of London.
What was the sample?
16 right-handed male London taxi drivers.
How were the participants chosen?
Had to have completed the “Knowledge” test and have their license for at least 1.5 years
To who were the taxi drivers compared to?
50 right-handed males who did not drive taxis
How were they compared?
Compared using MRI scans
From where were the control participants taken from?
Were taken from an MRI database
What were the 2 different techniques used to analyse the MRI scans?
Voxel-based morphometry (VBM)
Pixel counting
Results from the pixel counting
The pixel counting showed that the posterior hippocampi of taxi drivers were significantly larger relative to those of control subjects and the anterior hippocampi were significantly smaller.
Results from the Voxel-based morphometry (VBM)
VBM showed that the volume of the right posterior hippocampi correlated with the amount of time spent as a taxi driver.
No differences were observed in other parts of the brain.
Maguire argues that this demonstrates that the hippocampus may change in response to environmental demands.
Relation to neuroplasticity
By repeatedly firing the neurons required to remember the spatial layout of the city of London, the number of synapses was increased, creating a greater neural network
What to know for neuroplasticity
Neuroplasticity
The different scales of neuroplasticity
Synaptic plasticity - how it works
Maguire (2000)
Apoptosis
Neuronal cell death
Long-term potentiation
The repeated firing of a neuron strengthens the connection.
In other words, neurons that fire together, wire together.
This is the biological explanation of why rehearsal leads to memory consolidation.
Neurogenesis
The process by which new neurons are formed in the brain.
Synaptic pruning
Also known as neuronal pruning, this is a natural process where the brain eliminates extra synapses.
Synaptic pruning is thought to be the brain’s way of removing connections that are no longer needed.
