Maguire wanted to have a quasi-experimental study on the brain make up of taxi drivers in London.
There were 16 participants, where all of them were between the age of 32-62 (an average of 44). All of them were right-handed male, with at least 1 and a half years of taxi driving experience.
From the MRI scans, significantly increased gray matter volume is found in the brains of taxi drivers in the posterior hippocampi.
While controlled subjects showed a relatively greater gray matter volume bilaterally in anterior hippocampi relative to those of taxi drivers.
From the independent analysis techniques, it indicates that the professional dependence on navigational skills in licenced drivers is associated with a relative redistribution of gray matter in the hippocampus.
It can be speculated that the left hippocampus complements its partner by storing memories of people and events that occur in the rich context of taxi driving in the real world, where an over-arching framework - such as integrating information into an existing map - is not required.