Our human brain is a special navigation system, quite similar to satellite navigation, having in-built maps, grids and compasses claims neuroscientist Hugo Spiers.

The mechanism is located in the hippocampus region of the brain, which helps in memory and learning and is different in the case of a London taxi drivers, according to a study done by Eleanor Maguire at University College, London. The study indicates that a part of the hippocampus is enlarged in the case of a London taxi-driver as compared to the general population.

According to Spiers taxi-drivers in London need to be aware of all the winding streets and have strong innate sat-navs, which have been strengthened over a period of time and experience. Bus drivers also do not have such enlarged area and the difference between the taxi-drivers and the bus drivers is that the former is associated with information on hand regarding the 250,000 streets built up by these taxi drivers over a period of time.

As part of a follow-up study, Maguire and Spiers made use of the Playstation2 video game “ the Getaway” to study how the taxi drivers make use of their hippocampus and other brain areas while navigating.

The taxi drivers made use of the virtual reality simulation to navigate on the streets of London, while they were lying in an fMRI brain scanner. The researchers observed that the hippocampus was most active at a time when the drivers initially think of the route and plan well ahead.

In contrast to this, the activity in the diverse network of the other brain areas increased as they encountered road blocks, expected landmarks and view and worry about the thoughts their respective customers as well as other drivers. Spiers says that the hippocamous is important for navigation and we tend to use like a “sat-nav”. In the interior of the hippocampus as well as neighboring areas of the brain, scientists have observed three types of cells which form the “sat-nav”. These are known as head direction cells, place cells and grid cells.

Place cells help us in locating a place. They light up by saying “ you are here” when we come across a specific place. There are “hundreds of thousands of place cells in the brain.” Head direction cells behave like a compass. They inform us which way we are facing. Grid cells inform us as to how long we have travelled.

Source: To,September 16th,2008