Part 4

Making memories For the brain to learn things and to remember experiences, it needs to make memories. The hippocampus in the brain is important for creating memories– but there isn't just one type of memory. Remember when... I remember that! Episodic memory creates records of experiences, or "episodes". It's a multi-step process that involves a memory forming, being stored, then being recalled. The hippocampus is vital for all of this. 1 At the party Experiencing or learning something activates a number of neurons in different areas of the cerebral cortex and the hippocampus as the event happens. 2 A memory forms The spiking of these neurons together strengthens their connections. A memory is stored when the connections between the hippocampus and cerebral cortex get stronger. 3 Can you remember? Just a small reminder of the event, perhaps what you ate, makes the hippocampus switch those same neurons back on again. Then you remember the whole thing. OTHER TYPES OF MEMORY The brain uses different systems to learn new skills or temporarily hold information. Procedural memory Learning new skills, or "procedures", like playing the piano, is a different type of memory that doesn't involve the hippocampus. Instead, it requires synapses changing strength in the cerebellum and elsewhere. Working memory Holding information in the mind for a short time, such as when you're doing sums, involves neurons in the cerebral cortex spiking all the time that you're retaining the information.

制造记忆 大脑要学习知识、记住经历，就需要形成记忆。 大脑里的海马体对形成记忆十分重要——但记忆不止有一种类型。 还记得…… 我记得那件事！ 情景记忆会记录下我们的经历，也就是“情景片段”。 它是一个多步骤过程：先形成记忆，再储存起来，最后提取回忆。 海马体对整个过程都至关重要。 1 经历事件 事情发生时，你的经历或学习会激活大脑皮层与海马体不同区域的大量神经元。 2 形成记忆 这些神经元同步兴奋会强化它们之间的连接。 当海马体和大脑皮层之间的连接变强，记忆就储存完成了。 3 你能想起来吗？ 哪怕只是这件事的一个小小提示，比如你当时吃了什么，都会让海马体重新激活同一批神经元。 然后你就能想起整件事了。 其他类型的记忆 大脑会用不同的系统学习新技能，或是暂时保存信息。 程序性记忆 学习新技能也就是“流程”，比如弹钢琴，是另一种不需要海马体参与的记忆类型。 相反，它需要小脑和其他部位的突触改变连接强度。 工作记忆 短时间在脑中保存信息，比如做算术题的时候，要靠大脑皮层的神经元在你保留信息的过程中持续兴奋。

Emotions Emotions are your feelings about what's happening to you or the world around you. Emotions affect your body and behaviour, and how others respond to you. You show emotions through facial expressions. These tell others how you're feeling, so they can understand you. Four emotions Scientists now think there are only four basic emotions: happiness, fear, sadness, and anger. All the many different feelings you have are a mix of these four basic reactions. Emotional response Emotions cause your body and behaviour to change– but it works the other way round, too. Your physical state can make you feel a certain way. Take anger, for example: Bodily responses Fast heartbeat Deep breaths Blood goes to muscles ready for action Emotion Anger Behavioural responses Focus on problem Shouting Frowning Where does fear come from? The amygdala in the centre of the brain generates a feeling of fear. The hypothalamus controls your body's response to it, while the frontal lobe shapes how fear affects your behaviour.

情绪 情绪就是你对发生在自己身上或是周遭世界的事情产生的感受。 情绪会影响你的身体、行为，也会影响其他人对你的回应。 你会通过面部表情来表达情绪。 这些表情能告诉别人你的感受，让他们理解你。 四种基本情绪 现在科学家认为，情绪只有四种基本类型：快乐、恐惧、悲伤和愤怒。 你所有各种各样的感受，都是这四种基本反应组合而成的。 情绪反应 情绪会让你的身体和行为发生改变——反过来，这个关系也同样成立。 你的身体状态也会让你产生某种特定的感受。 举愤怒的例子：身体反应：心跳加快 深呼吸 血液流向肌肉准备行动 情绪：愤怒 行为反应：专注问题 大喊 皱眉 恐惧从哪里来？ 大脑中央的杏仁核会产生恐惧的感受。 下丘脑控制着身体对恐惧的反应，额叶则决定了恐惧会如何影响你的行为。

Thinking and intelligence Thinking is the most complex thing a brain does. It involves combining new sensory information with previously stored memories, working out what it all means, then deciding what to do. Remember the worms on page 25? Their simple brains collect sensory information, then automatically respond to it. Sometimes humans do this, but often we stop and think. Rules vs. creativity Sometimes intelligence requires working out the right answer from known rules– like in maths. Other times, the best solution is creating something completely new, like when you write a story or paint a picture. Thinking ahead Intelligence is about solving problems using your imagination. First you must decide what your aim is, then imagine different actions you could take, and finally choose the best option for a happy result. Here's an example: Oh no! Imagine walking along and seeing a friend drop their scarf when it's cold. You can imagine the different outcomes. Thinking it through Without the scarf, your friend might get cold. You can also imagine their emotions– they might be sad to have lost it. Finding a solution If you pick up the scarf and return it to your friend, the problem is solved! They are happy and warm, and you are happy to have helped. CONSCIOUSNESS Consciousness is the personal experience of being alive. You aren't conscious when you sleep. The brain's workings create consciousness, but why exactly we feel it is still a great mystery!

思考与智力 思考是大脑做的最复杂的工作。 它需要把新获得的感官信息和之前储存的记忆结合起来，弄明白所有信息的含义，再决定接下来要做什么。 还记得25页的蚯蚓吗？ 它们简单的大脑收集到感官信息后，就会自动做出反应。 人类有时候也会这样，但大多时候我们会停下来思考。 规则与创造力 有时候智力要求我们从已知规则中找出正确答案——就像做数学题一样。 另一些时候，最好的解决方案是创造出全新的东西，比如你写故事或是画画的时候就是这样。 提前思考 智力就是用想象力解决问题的能力。 你得先确定目标，再想出不同的可行行动，最后选出能带来好结果的最佳方案。 举个例子： 哎呀！ 想象一下，天冷的时候你走在路上，看见朋友的围巾掉了。 你可以想象不同的结果。 仔细想想 没有围巾，你的朋友可能会着凉。 你也能体会他们的心情——丢了围巾他们会难过。 找到解决办法 如果你捡起围巾还给朋友，问题就解决啦！ 他们很开心也不会冻着，你也因为帮了忙而开心。 意识 意识就是你作为个体活着的个人体验。 你睡着的时候没有意识。 大脑的活动产生了意识，但我们至今还不清楚意识为什么会产生，这仍然是一个巨大的谜题！

Sleeping and dreaming Every night you do something very mysterious– you sleep and dream. Scientists don't fully understand why these processes happen, but we do know that they help to keep the brain healthy. Light and deep sleep During the night you move through different types of sleep, which have different jobs. In deep sleep you are very difficult to wake. REM sleep is much lighter, and dreams mainly happen then. REM stands for "rapid eye movement". When you dream, your closed eyes dart about. Daily rhythms Over each day's 24-hour cycle, your brain and body's activities change to match the time. When it gets dark, the brain tells the body it is time to sleep. Sorting memories Scientists think that dreams help mix the new memories you made in the day with memories already stored in your brain. Deep sleep might also help change new memories into long-term ones. Cleaning the brain When a brain is busy in the day, rubbish builds up– including old neurotransmitters and other chemical waste. During deep sleep, the brain washes away this material.

睡觉又做梦 你每晚都会做一件非常神奇的事——你会睡觉、做梦。 科学家还没有完全弄清这些过程发生的原因，但我们确定，它们能帮助大脑保持健康。 浅睡与深睡 夜里你会经历不同类型的睡眠，每种睡眠都承担不同的作用。 深度睡眠时，你很难被叫醒。 REM睡眠程度更浅，梦大多都发生在这个阶段。 REM是"快速眼动"的英文缩写。 你做梦的时候，闭着的眼睛会快速转动。 日常节律 在一天24小时的循环里，你的大脑和身体活动会跟着时间调整变化。 天色变暗后，大脑就会告诉身体该睡觉了。 整理记忆 科学家认为，梦能帮你把白天形成的新记忆，和大脑里已经储存的旧记忆融合在一起。 深度睡眠也能帮助把新记忆转化为长期记忆。 清洁大脑 白天大脑不停忙碌的时候，会堆积不少垃圾——包括老旧的神经递质和其他化学废物。 深度睡眠时，大脑就会把这些废物冲走。

The ageing brain The brain changes throughout life– it gets better at some things and worse at others. Living a healthy life can help keep the brain in good condition. Older and wiser As you get older, you gain more memories and knowledge. Some brain processes keep improving during adulthood, such as certain maths skills and thinking about complex problems. Brain drain From around 30 years old, human brains start to shrink gradually. Both episodic and working memory get slightly worse with age. Other thought processes also become slower. Brain illness Some brain diseases are more common in old age. Alzheimer's disease causes neurons to die and areas of the brain to shrink. This can lead to confusion and forgetfulness. Cerebral cortex This is where language and thoughts are made and where information is processed. Hippocampus This area is essential for the brain to make new memories. Ventricles These spaces in the brain get bigger as neurons shrink and die. Hippocampus Lots of shrinkage here can cause memory loss and forgetfulness. Cerebral cortex Thinking can become confused as this area shrinks. HEALTHY BODY, HEALTHY BRAIN Exercising regularly and eating healthy food helps the brain to age better. It's also important to use your brain a lot– thinking hard and educating yourself may help to protect the brain from illness.

逐渐老化的大脑 大脑一生都在变化——它有些能力会变强，有些会变弱。 健康的生活方式能帮助大脑保持良好状态。 越老越有智慧 随着年龄增长，你会拥有更多记忆和知识。 有些大脑功能在成年后还会持续提升，比如特定的数学能力和思考复杂问题的能力。 大脑萎缩 大约从30岁开始，人类的大脑就会慢慢开始萎缩。 情景记忆和工作记忆都会随着年龄增长略微变差。 其他思维过程也会变慢。 脑部疾病 有些脑部疾病在老年更为常见。 阿尔茨海默病会造成神经元死亡，大脑部分区域萎缩。 这会导致意识混乱和记性变差。 大脑皮层 这里是产生语言、想法，处理信息的地方。 海马体 这个区域对大脑形成新记忆来说必不可少。 脑室 神经元萎缩死亡后，大脑里的这些空腔会变大。 海马体 海马体萎缩严重会造成失忆和记性变差。 大脑皮层 这片区域萎缩后，思考会变得混乱。 健康身体，健康大脑 规律运动和健康饮食能帮助大脑更好地应对衰老。 经常动脑也十分重要——努力思考、坚持学习或许能帮助保护大脑，远离疾病。

Our different brains A person's DNA and their life experiences shape how their brain works. Knowing the differences that can occur in individuals" brains is helpful for understanding the challenges some people face. Dyslexia Many people have dyslexia, which can make reading and making sense of words difficult. For people with dyslexia, connecting written words with the sounds of words can be tricky. Autism Individuals can have very different experiences of autism. People with autism often find communication difficult. They may also dislike loud noises and bright lights, and find busy places confusing. MENTAL HEALTH We can all feel sad and upset from time to time. However, some people feel like this all the time, and this could be a sign that their mental health needs looking after. The reasons can be hard to explain but, just like physical problems, the feelings can be treated and made better. ADHD Attention deficit hyperactivity disorder (ADHD) can make it difficult for people to concentrate or to stay still. People with ADHD are often very active and quickly switch from one task to another. How to help If you are struggling with a problem, talk to a person you trust. If you see someone else who needs help, ask how they are and always remember to be kind and try to understand their feelings.

各不相同的大脑 一个人的基因和人生经历，决定了大脑的工作方式。 了解不同人大脑的差异，能帮助我们理解一些人面临的困境。 阅读障碍 很多人都有阅读障碍，这会让阅读和理解文字变得困难。 对有阅读障碍的人来说，把书面文字和文字的读音对应起来是件难事。 自闭症 不同自闭症患者的经历差异很大。 自闭症患者通常在沟通方面存在困难。 他们可能不喜欢喧闹的噪音和明亮的光线，也会觉得热闹拥挤的地方让他们不适。 心理健康 我们所有人都会偶尔感到伤心难过。 但有些人一直都有这样的感受，这可能说明他们的心理健康需要照料。 原因可能很难解释，但就像身体出问题一样，这些情绪问题可以得到治疗、慢慢好转。 注意缺陷多动障碍（多动症） 注意缺陷多动障碍（多动症）会让患者很难集中注意力，也很难安静待着。 多动症患者通常非常活跃，会很快从一件任务切换到另一件。 如何提供帮助 如果自己正被问题困扰，就找你信任的人倾诉。 如果你看到别人需要帮助，可以问问他们的感受，永远记得要友善，试着去理解他们的心情。