Maguire

• Background

  • The hippocampus is a region of the brain that is involved in spatial memory
  • Maguire reports that in some species of animals 'hippocampal volumes enlarge during seasons when demand for spatial ability is greatest'
  • This suggests that the hippocampus has plasticity
• Aim


  Maguire wanted to find out if there is also plasticity in humans
• Sample

  • 16 right-handed males
  • From London
  • Taxi drivers with 'the knowledge;
• Procedure - quasi experiment

  • Taxi drivers all had an MRI scan of their brain
  • MRIs were compared to those of a control group. The brain scans chosen for the control group were taken from among those already on record at wellbeing institute in London
  • Maguire chose 50 scans to compare to the taxi drivers against, with all being right-handed males aged 32-60
• Procedure - quasi-experiment pt 2

  • The scans of the 16 taxi drivers and 50 people in the control group were analysed in two ways
  • Pixel counting: this was a 2D measurement of the area. Involved pixels being counted manually in only the hippocampus
  • Voxel-based morphoteny - this was a 3D measure of volume. Done by a computer and done on the whole brain
  • In both cases it was the amount of grey matter counted
• Quasi experiment findings

  • The only region of the brain where a significant difference was found between the volume of grey matter was the hippocampus. Compared against the controls, the taxi drivers had:
  • Significantly more grey matter in the prosteria
  • Significantly less grey matter in the anterior
• Procedure - correlation

  • MRI scans were further analysed
  • Maguire was interested in whether there was a correlation between (1) length in time (in years) as a taxi driver and (2) volume of grey matter in the hippocampus
• Correlation findings

  • There was a positive correlation between (1) length of time in years as a taxi driver and (2) volume of grey matter in the prosterior hippocampus
  • There was a negative correlation between (1) length of time in years as a taxi driver and (2) volume of grey matter in the anterior part of the hippocampus
• Conclusions

  • The quasi experiment part of the study confirmed that the human brain (or at least the hippocampus) has plasticity
  • The correlation part of the study suggests that changes in the hippocampus can occur in line with demands placed in taxi drivers by their job