Biological Approach - The Brain and Behaviour - Neuroplasticity

Question 1

Neuroplasticity

Answer 1

The brain’s ability to change structurally and chemically by experience (in response to the environment)

The brain changes:

• At the beginning of life when immature brain organises itself
• In cases of brain injury, to compensate lost functions
• Whenever something new is learned or memorised

Neuroplasticity process:

1. Neurogenesis
   - The formation of new neurons in response to experience
2. Dendritic branching (=grey matter)
   - Which allows the brain to make new synaptic connections
3. Synaptic connections…
   - Strengthen due to long term potentiation (where the experience continues)
   - Break due to neural pruning (where the experience stops)

Question 2

Hippocampus

Answer 2

A structure in the brain located in the medial temporal lobe. One in each hemisphere

Functions:
- To facilitate spatial memory in the form of navigation

Question 3

MRI

Answer 3

Magnetic Resonance Imaging

In an MRI scan, the body scanned is placed in a strong magnetic field.

Radio waves are sent through, affecting the orientation of the atoms in the body

When it is turned off, the atoms go bak to their orientation which emits different energy

A computer will then produce a 3D representation that shows the different structures of the brain

This allows detection of sizes of structures and structural abnormalities in the brain scanned

Question 4

Maguire et al. (2000)

Answer 4

Aim:
- Whether the healthy human brain can undergo “plastic” (structural) changes in response to extensive navigational experience

Pps:

• 16 right-handed male taxi drivers
• 50 right-handed male non-taxi drivers

Procedure

An MRI scan was made
- 24 sagittal slices
- 6 from anterior hippocampus 
- 12 from the body of the hippocampus
- 6 from posterior hippocampus
- for each slice the nb of pixels of hippocampus was 
    counted

Results:
No difference in the overall volume between taxi and non-taxi drivers

The volume of taxi drivers’ posterior hippocampi were significantly larger than controls

The volume of controls’ anterior hippocampi were significantly larger

Positive correlation between time as taxi driver and volume of posterior hippocampus (r=0.5)

Negative correlation between time as taxi driver and
volume of anterior hippocampus (r=-0.6)