Our brain is probably the most important organ in our body. It's an incredibly complex thing that helps us think, speak, feel and move. It's no wonder we need to look after it and just like the rest of our body, we need to keep it exercised to keep it healthy.

Our brain is made up of 86 billion neurons – or nerve cells – but as we get older some of these slowly die off. In extreme cases, nerve cells in different areas of the brain become damaged and eventually die causing a condition called dementia where a person is unable to perform certain mental functions.
It's a good idea to train our brain by learning ways to increase our memory or intelligence. I like to stretch my brain by doing a crossword or a Sudoku puzzle. There's also evidence that learning a second language can boost your brainpower. Dr Catherine Loveday, who's a neuropsychologist, thinks being bilingual is a protective factor for the brain because it "involves a lot of switchings and that seems to exercise the sort of executive parts of our brain. Those parts of the brain are kind of stronger and fitter when it comes to resisting some kind of damage from a stroke."
But if you're not bilingual there are other ways to stretch your brain: If you're right handed, doing tasks like brushing your teeth with your left hand will improve your brain – or something I find very challenging, memorising a list of words, such as a shopping list.
The main aim of trying these skills is to stimulate the brain. This is something Dr. Loveday describes as building up our cognitive reserve – that's building up extra abilities to help protect the brain against declining memory or thinking. She says "even if people take up languages or take up other things later in life it will give them a degree of protection." As I get older, that has put my mind at rest!
The best bit of research I have read is that eating chocolate may enhance our ability to acquire and utilise knowledge – that's our cognitive performance. It may not be healthy for the rest of my body but at least it might make me a brain box! What do you think?
词汇表
organ 器官
neurons 神经元
nerve cells 神经细胞
dementia 痴呆症、失智症
mental functions 脑功能
intelligence 智力
crossword 填字游戏
brainpower 脑力，智力
neuropsychologist 神经心理学家
bilingual （能使用）两种语言的，双语的
executive 执行指令的
resisting 抵抗，抵御
stroke 中风
stimulate 促进（身体某部位）的功能
challenging 有挑战性的
cognitive reserve 认知储备
abilities 能力
put my mind at rest 让我放心了
enhance 提高，增强
utilise 利用，使用
cognitive performance 认知表现，认知能力
a brain box 非常聪明的人