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Physically the human brain is very boring. Alan Turing described it as looking like a bowl of cold porridge. To get to the porridge you must first cut through the skull, a two-millimeter thick protective layer of bone. The adult human skull has almost no gaps in it, and the only ways into the brain without a bone saw are through the eye sockets or the soft area of bone at the back of the nose. Egyptian mummies had their brains removed through the nose and preserved in a jar for the afterlife!

Thinking with Porridge
Protecting the brain is very important and the skull does a good job by being a tough, impenetrable barrier. But sometimes this toughness backfires. In 2006, Richard Hammond, one of the presenters of the TV motoring series Top Gear, suffered a crash while testing a land speed record-breaking car. Although he was in a multipoint harness, the crash, at over 200 miles per hour, bounced his helmeted head around the inside of the cockpit and his brain was badly bruised. As you know from experience, when you bruise you get swelling, and the brain is no exception. However, the brain is encased in bone, so this swelling has nowhere to escape. The resulting buildup of pressure is dangerous, causing an interruption of blood supply to the un-bruised parts. Brain damage in such accidents is often fatal; Richard Hammond was very lucky to live through the experience.

Surgeons often need to cut into the skull to relieve pressure on the brain, or to gain access to remove tumors. Going through the scalp involves a great deal of blood, but once you have a clean hole in the skull you can peel back the thin membranes, called the meninges, to reveal a wrinkly folded whitish thing that looks a bit like a cauliflower. This is the outer surface of the brain where much of our thinking is done. Unfolded, this surface layer would cover the area of a football field and this intense folding distinguishes the human brain from the brains of simpler animals. Some animals, such as elephants and dolphins, have larger brains than ours, but the area of their folded surface is considerably smaller. It is thought that this efficient folding is key to giving us the ability to think complex thoughts.

Analysis of Einstein’s brain held at Princeton University shows it is not particularly massive, but it is strikingly more folded than average, and has a shorter lateral sulcus – the fissure between the front and back

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