1 Aim: To determine whether there are
changes in the brains of humans
experiences of extreme spatial navigation.
2 Participants: 16 male licensed
London cab drivers between
the ages of 32-62, all were right
handed, all were described as
having healthy medical,
neurological and psychiatric
2.1 Control group: Selected 50 scans from the structural MRI scan
database at the same center where the cab drivers were
scanned. All scans were from healthy right handed males aged
between 32-62. They were not cab drivers.
3 Procedure: Quasi experiment. Independent variable is
cab drivers. Dependent variable is volume of
hippocampus. Data was collected through two different
techniques of analysing MRI scans. These were voxel
based morphology and pixel counting.
4.1 Cab drivers: increase in volume of posterior
hippocampus. But it didn't change the overall size
of the hippocampus. Therefore the volume of the
anterior hippocampus has decreased.
4.2 Control group: Greater volume of
anterior hippocampus, but the
overall size is the same.
4.3 Correlations: Positive correlation
between volume of grey matter in
posterior hippocampus and time as a cab
driver. Negative correlation between
volume of grey matter in the anterior
hippocampus and time as a cab driver.
5.1 People who have experience extreme spatial
navigation will have an increased size of their
posterior hippocampus compared to those who
have not experience extreme spatial navigation.
6.2 Only 16 people studied
6.3 All right handed and aged
32-62. Ignores left handed and
other aged people.
6.4 Right handed is a control -
limiting extraneous variables.
6.5 Control group don't know scans are being
used - no right to withdraw.
6.6 On database, therefore likely
to have given consent.
6.7 Characteristic of control group
similar to cab drivers.
6.8 Two methods used to look at
scans allows for comparison