Maguire

• What brain structure is involved with memory and navigation?

  Hippocampus
• Why is the hippocampus particularly important for navigation?

  It is larger in animals relying on navigation
• What does the size of the hippocampus indicate in small mammals and birds?

  It indicates reliance on navigational skills
• What happens to the hippocampus when navigational skills are needed?

  It can increase in size
• What was the aim of Maguire's study?

  To demonstrate the hippocampus's role in navigation
• What type of research method was used in the study?

  Quasi experiment
• What was the independent variable (IV) in the study?

  Participants' status as taxi drivers
• What was the dependent variable (DV) in the study?

  Grey matter volume and density
• How were the taxi drivers' brains scanned?

  Using an MRI scanner
• What type of MRI scans were used in the study?

  Structural MRI scans
• What does VBM stand for?

  Voxel-based morphometry
• What does VBM identify in MRI scans?

  Regional differences in grey matter density
• How many slices were the scans separated into?

  26 slices
• How many slices focused on the hippocampus?

  24 slices
• How many taxi drivers participated in the study?

  16 taxi drivers
• What was the mean age of the taxi drivers?

  44 years
• How long had the taxi drivers been licensed?

  At least 1.5 years
• What was the average time spent as a taxi driver?

  14.3 years
• What was the age range of the non-taxi drivers?

  32-62 years
• How were the non-taxi drivers selected for the study?

  From an MRI database without health problems
• What was the criterion for the non-taxi drivers' health status?

  No health problems were included
• Who conducted the pixel counting on the scans?

  One person experienced in the technique
• What was the purpose of pixel counting in the study?

  To analyze grey matter volume
• How does the study ensure objectivity in the pixel counting process?

  The counter was blind to participants' identities
• What is a pixel in the context of this study?

  A 2-D measurement of volume
• What was the mean time spent 'being on the knowledge' for taxi drivers?

  Two years
• What was the age range of the taxi drivers?

  32-62 years
• What was the selection criterion for the taxi drivers in the study?

  Healthy general medical profiles
• How does the study compare taxi drivers to non-taxi drivers?

  By comparing grey matter volume and density
• What was found in the grey matter volume of taxi drivers?

  Increased grey matter in posterior hippocampi
• Where was relatively more grey matter volume found in non-taxi drivers?

  In the anterior hippocampi
• What did pixel counting analysis reveal about the hippocampus volume?

  No overall volume difference between groups
• What regional difference was found in the anterior hippocampus?

  Non-taxi drivers had greater anterior right volume
• What regional difference was found in the posterior hippocampus?

  Taxi drivers had greater posterior volume
• What was the purpose of the correlational analysis?

  To see correlation between hippocampal volume and driving time
• What correlation was found between time as a taxi driver and hippocampal volume?

  Positive correlation with right posterior hippocampus
• How did the length of time as a taxi driver correlate with the anterior hippocampus volume?

  Negatively correlated
• What are the main findings regarding hippocampal volume in taxi drivers versus controls?

  • Taxi drivers: greater posterior hippocampal volume
  • Non-taxi drivers: greater anterior hippocampal volume
  • Positive correlation between driving time and hippocampal volume
• What does the report suggest about the relationship between brain changes and being a taxi driver?

  Changes are due to job demands, not pre-existing differences
• What does the positive correlation between hippocampal volume and driving time suggest?

  Hippocampal changes occur with spatial memory demands