Expertise might also come with a dark side, as all those learned patterns make it harder for us to integrate wholly new knowledge. Consider a recent paper that investigated the mnemonic performance of London taxi drivers. In the world of neuroscience, London cabbies are bestknown for their demonstration of structural plasticity in the hippocampus, a brain area devoted (in part) to spatial memory. Because the cabbies are required to memorize the entire urban map of London – it’s the most rigorous driving test in the world – their posterior hippocampi swell and expand, leading to permanent changes in the brain. Knowledge shapes matter.
However, the same researchers that documented the expansion of the hippocampus are now documenting the tradeoffs of all that extra spatial information. The problem with our cognitive chunks is that they’re fully formed – an inflexible pattern we impose on the world – which means they tend to be resistant to sudden changes, such as a street detour in central London. They also are a practiced habit, and so we tend to rely on them even when they might not be applicable. (A chess grandmaster has to be careful about applying his chess chunks to checkers.)