London Cabbies Have An Enlarged Hippocampus

The black taxi cab is a classic sight on London's streets, and their drivers - fondly known as cabbies - are the focal point of new, innovative research into Alzheimer’s.

Cabbies have an incredible knowledge of London streets that seems to confer some protection against Alzheimer’s Disease, and this could be be clinically relevant to struggling patients, or those seeking to mitigate their risks. How so? It seems that their 'knowledge' of London’s streets holds the secret.

“The Knowledge,” as the cabbie exam is called, was originally established for horse and buggy cabbies in 1865. It ranks amongst the hardest mental examinations as it involves the repeat retrieval from memory of minute details from as many as 56,000 London streets, depending on who’s reporting, from Marble Arch to the tiniest residential lanes.

University College London and Alzheimer’s Research UK are treaming up to study the brains of these cabbies, as it’s found that the hippocampus, master of the brain’s short-term memory and spatial memory systems, is enlarged in the brains of cabbies.

For Alzheimer’s disease, the hippocampus is the first and principal victim of its effects. Furthermore, cabbies’ hippocampi continue to enlarge the more years they put into the job, presenting the hypothesis that perhaps there’s something we can do to replicate the effect in the general population.

The research team hope to study the “brain gain” which occurs from putting one’s powers of memory through the rigors of The Knowledge. So, to gather more detail on the mechanisms that cause these gains, they have recruited thirty London cabbies to drive around on their routes hooked up to an MRI machine that will allow the researchers to gather real-time observations of the workings within the hippocampus.

OGN will report back when the research data has been collected and analysed. In the meantime, it might be wise for all of us to stop using Google Maps.