Maguire

• Maguire was inspired by Blakemore and Cooper who looked at functional brain plasticity but she wanted to investigate structural brain plasticity.
• The hippocampus is a major part of the limbic system in charge of navigation. Previous research had suggested that the volume of the hippocampus in animals enlarge when navigational skills are required.
• Maguire wanted to see if the volume of the hippocampus would plasticise due to environmental changes os she looked at London taxi drivers who had navigational experience and knowledge.
• Maguire aimed to investigate the difference in volume of London taxi drivers hippocampi compared to non-taxi drivers.
• Maguire investigated 16 taxi drivers with a mean job duration of 14 years. She compared these with 16 controls. They were all right handed, male and had a mean age of 44.
• Maguire procedure:

  1. Taxi drivers brains scanned using an MRI scanner. The control group were taken from an MRI scan database,
  2. All scans were analysed using VBM which identifies grey matter density in regions of the brain,
  3. Used pixel counting to compare the volume of the anterior, body and posterior of the the hippocampus.
• Maguire found no overall difference in the volume of the hippocampus but:

  • Taxi drivers had significantly increased volume in posterior hippocampus (used for spatial processing) compared to non taxi drivers,
  • Taxi drivers had reduced volume in the anterior hippocampus (used for new routes) compared to non taxi drivers,
  • There is a negative correlation between time spent taxi driving and volume of anterior hippocampus,
  • There is a positive correlation between time spent taxi driving and volume of posterior hippocampus.
• Maguire concluded that there are regionally specific structural differences in the hippocampus of taxi drivers and non taxi drivers. Also that brain plasticity does occur as a result of prolonged environmental stimulus.