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<\/div>THE myth that we use only 10 per cent of our brains has been comprehensively debunked. Perhaps it persists because it is so appealing to believe that you could become a genius simply by learning to engage the dormant 90 per cent. In reality, no part of your brain is surplus to requirements, and it is always switched on, even when you are asleep or not thinking about much at all.<\/p>\n
But that doesn\u2019t necessarily mean that your brain burns the same amount of energy while daydreaming as it does when you are concentrating. We have all experienced that feeling of mental exhaustion after focusing on a tricky problem. Detailed thinking certainly feels like hard work, but is it? The answer is a touch more subtle than you might suspect.<\/p>\n
The brain is certainly a hungry organ. \u201cIt is the most energy-consuming part of the body,\u201d says Nilli Lavie<\/a> at University College London. Although it accounts for around 2 per cent of our body weight, it uses some 20 per cent of the energy we burn at rest.<\/p>\n Most of this energy is used to maintain different levels of electrical charge across the membranes of neurons \u2013 an imbalanced state that needs to be restored after a neuron has fired off a signal. \u201cThat requires a lot of fuel,\u201d says Ewan McNay<\/a> at the University at Albany in New York.<\/p>\n Intriguingly, when it comes to energy use, the brain doesn\u2019t distinguish between tasks that we traditionally regard as \u201chard\u201d and those that come more naturally. This was first\u2026<\/p>\n<\/p><\/div>\n