Level 3 Reading 10A

Ch.19

第19章

Reading 10A WHAT'S ON YOUR MIND? The ancient Egyptians thought so little of the brain that when a king died, they removed the brain from his body and threw it away. The Egyptians presumed, like many people before and after them, that consciousness—your mind and your thoughts—existed in the heart. Now we know that the mind is a product of the brain, but how exactly does this 1.5-kilo piece of matter create a mind that allows you to think about yourself, experience happiness and anger, or remember events that happened 20 minutes or 20 years ago? This isn't a new question. Today, however, powerful new techniques for visualizing the sources of thought, emotion, behavior, and memory are transforming the way we understand the brain and the mind it creates. Have you ever stopped and thought, "What's wrong with me today? I just don't feel like myself"? Perhaps you were more tired or worried than usual—but somehow, you knew that something was different about you. This self-awareness—the ability to think about yourself and how you're feeling—is an important part of being human. This part of your mind has its origins in the prefrontal cortex— a region of your brain just behind your forehead that extends to about your ears. Before this area began to function (around age two), you didn't understand that you were a separate individual with your own identity. As this part of your brain developed, you became more aware of yourself and your thoughts and feelings. The temporal lobe—a part of the brain associated with perception and speech— helped you understand and put into words these thoughts and feelings. Perhaps one of the most important factors involved in shaping our identity is memory. What exactly is a memory? Most scientists define it as a stored pattern of connections between neurons in the brain. Every feeling you remember and every thought you think alters the connections within the vast network of brain cells, and memories are reinforced, weakened, or newly formed.

读数10A 你在想什么？ 古埃及人很少考虑大脑，以至于当一位国王去世时， 他们从他身上取下大脑，扔掉了。 埃及人和他们之前和之后的许多人一样， 意识——你的头脑和思想——存在于心中。 现在我们知道，头脑是大脑的产物， 但这1.5公斤的东西到底是怎么回事 创造一种让你思考自己、体验快乐和愤怒的心态， 或者还记得20分钟或20年前发生的事件吗？ 这不是一个新问题。 然而，今天，用于可视化思想、情感来源的强大新技术， 行为和记忆正在改变我们理解大脑及其创造的思维的方式。 你有没有停下来想，“我今天怎么了？我就是感觉不舒服”？ 也许你比平时更累或更担心，但不知何故，你知道自己有些不同。 这种自我意识——思考自己和感受的能力——是人类的重要组成部分。 你大脑的这一部分起源于前额叶皮层-- 前额后面延伸到耳朵附近的大脑区域。 在这个区域开始发挥作用之前（大约两岁）， 你不明白你是一个有自己身份的独立个体。 随着大脑这一部分的发育，你对自己以及你的想法和感受有了更多的认识。 颞叶——大脑中与感知和言语相关的部分-- 帮助你理解并用语言表达这些想法和感受。 也许塑造我们身份的最重要因素之一是记忆。 记忆究竟是什么？ 大多数科学家将其定义为大脑中神经元之间存储的连接模式。 你记得的每一种感觉和你想到的每一个想法都会改变庞大的脑细胞网络中的连接， 记忆被强化、削弱或新形成。

Most people's earliest memories reach back to about age three or so. Very few people remember anything before this time because the part of the brain that helps form long-term memories (the hippocampus) was not yet fully developed. This doesn't mean earlier memories don't exist in your mind, though. Some scientists believe highly emotional memories, especially those associated with intense fear, might be stored in another structure in the brain (the amygdala) that may be functional at birth. Although these memories are not accessible to the conscious mind, they might still shape the way we feel and behave, even into adulthood. But where do our emotions come from, and how do they shape the people we are and the way we perceive the world? Forty years ago, psychologist Paul Ekman demonstrated that facial expressions used to exhibit certain emotions are recognized by people everywhere. Ekman suggested that these emotions and their corresponding facial expressions evolved to help us deal quickly with situations that can affect our welfare. Though humans may share certain emotions and recognize them in others, we don't all have the same emotional response to every situation. In fact, most emotional responses are learned and stored in our memories. The smell of freshly cut grass, for example, will generate happy feelings in someone who spent enjoyable childhood summers in the countryside, but not in someone who was forced to work long hours on a farm. Once an emotional association like this is made, it is very difficult to reverse it. "Emotion is the least flexible part of the brain," says Ekman. But we can learn to control our emotions by becoming consciously aware of their underlying causes and by not reacting automatically to things in our environment. But is it really possible to control our emotions? Researcher Richard Davidson has demonstrated that people who experience negative emotions display activity in their right prefrontal cortex. In those with a more positive perspective, the activity occurs in the left prefrontal cortex. Could we, Davidson wondered, control this activity and shift our mental state away from negative feelings toward a calmer state of mind? To answer this question, Davidson worked with a group of volunteers in the United States. One group received eight weeks of training using different meditation and relaxation techniques, while another group did not. By the end of the study, those who had meditated had accomplished their goal: They showed a clear shift in brain activity toward the left, "happier" frontal cortex. For centuries, people have studied the brain, but it is only in recent years that we have really started to learn how it works. Nevertheless, there is still a long way to go before we understand our mind's many complexities.

大多数人最早的记忆可以追溯到大约三岁左右。 很少有人记得这之前的事 因为大脑中帮助形成长期记忆的部分（海马体）尚未完全发育。 不过，这并不意味着你的脑海中不存在早期的记忆。 一些科学家认为，高度情绪化的记忆，尤其是那些与强烈恐惧相关的记忆， 可能存储在大脑中的另一个结构（杏仁核）中，该结构在出生时可能具有功能。 虽然这些记忆对意识来说是不可访问的， 即使到了成年，它们仍可能塑造我们的感受和行为方式。 但我们的情绪从何而来， 它们是如何塑造我们的人和我们感知世界的方式的？ 40年前，心理学家Paul Ekman 证明了用于表现某些情绪的面部表情被世界各地的人所识别。 埃克曼认为，这些情绪及其相应的面部表情 进化来帮助我们快速处理可能影响我们福利的情况。 尽管人类可能共享某些情绪，并在其他情绪中识别出它们， 我们并非对每种情况都有相同的情绪反应。 事实上，大多数情绪反应都是在我们的记忆中学习和储存的。 例如，新鲜割草的味道， 会给在农村度过愉快童年夏天的人带来快乐的感觉， 但对于那些被迫在农场长时间工作的人来说，情况并非如此。 一旦形成这样的情感联系，就很难逆转。 埃克曼说：“情绪是大脑中最不灵活的部分。”。 但我们可以通过有意识地意识到情绪的根本原因来学会控制情绪 以及对环境中的事物没有自动反应。 但真的有可能控制我们的情绪吗？ 研究人员理查德·戴维森已经证明，经历负面情绪的人会在他们的右前额叶皮层中表现出活动。 在那些观点更积极的人中，这种活动发生在左前额叶皮层。 戴维森想知道，我们能不能， 控制这种活动，把我们的精神状态从负面情绪转移到更平静的状态？ 为了回答这个问题，Davidson与美国的一组志愿者合作。 一组接受了为期八周的不同冥想和放松技巧的训练，而另一组则没有。 到研究结束时，那些冥想过的人已经实现了他们的目标： 他们发现大脑活动明显向左侧“更快乐”的额叶皮层转移。 几个世纪以来，人们一直在研究大脑， 但直到最近几年，我们才真正开始了解它是如何工作的。 然而，在我们理解我们大脑的许多复杂性之前，还有很长的路要走。

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