“Barrett is the most provocative thinker on the human mind.” _Adam Grant, Professor of Psychology at Wharton School, Author of 《Give and Take》 and 《Think Again》 A "very short lecture on neuroscience" from a scientist in the top 1% of the world The human brain is not just for 'rational thinking.' So what is its ultimate purpose? The 'triune brain' is a myth. The framework for understanding the human brain has long since changed. If the brain predicts almost all of my actions, who chooses and takes responsibility for my life? The reason we must rescue children from abuse and poverty as soon as possible lies in our 'brain.' How do chronic stress and verbal abuse actually harm our bodies? The reason it is normal for there to be such diverse and conflicting minds in the world. The brain creates all the social realities we experience 'in our heads.' Seven and a half doors into the world of the brain. Have you ever wondered why we have brains? Do you remember nodding your head while reading about the 'triune brain' in famous journals and marketing books? Have you ever wondered what goes on in the mind of someone who posts thoughts on social media that are simply unacceptable? In her new book 《Seven and a Half Lessons About the Brain》, renowned neuroscientist Lisa Feldman Barrett shares a very different story about the 1.4-kilogram gray mass that sits between our ears compared to other neuroscience books. According to Professor Jeong Jae-seung of KAIST, who edited this book, it is “a collection of the essence of 21st-century neuroscience” and “a very unique series of lectures.” The book contains seven short but powerful lectures from the forefront of neuroscience research, along with a brief glimpse into the vast evolutionary history of the brain (the author calls it the 1/2 lecture). Each segment contains key discoveries and discussions in 21st-century neuroscience. The stories in this book begin with a brief summary of the history of evolution and neuroscience, quickly expanding into major issues in our daily lives and society. It offers insights that are easy and engaging while simultaneously awakening fundamental questions, instantly broadening the reader's intellectual curiosity and inner world. We have known too little about the brain. An undeniably optimal guide to understanding today's neuroscience. The brain is the center of human beings. Over the past few decades, as serious neuroscience research has become possible, advice based on the facts revealed by neuroscience has poured into various fields, from personal relationships to politics, economics, education, marketing, and healthcare. However, keeping up with this flow of knowledge and updating new information is not easy for the public, let alone for experts. As a result, the world we encounter is filled with outdated knowledge, misconceptions, distorted facts, and debates driven by vested interests, all mixed with exciting and sometimes revolutionary new knowledge. So how well do we really understand this crucial brain today? Furthermore, if our perspectives and thoughts about the brain change, how much could human life change? Barrett, a distinguished professor of psychology at Northeastern University and the chief scientific officer at Harvard Medical School's Center for Law, Brain, and Behavior, is a global scholar who has transformed the paradigms of neuroscience and psychology centered on the study of human emotions. Barrett has argued that emotions, which have long been considered primal instincts, are social constructs, and that humans actively construct their emotional experiences rather than passively receiving them. Throughout 《Seven and a Half Lessons About the Brain》, Barrett's unique innovative perspective is revealed. She examines how the brain originated, why it is important, its structure, and how it works with other brains to create everything we experience, using the best scientific lens based on what science has produced so far. Each of the seven and a half lectures presents fascinating facts about the brain, each containing important perspectives on human nature. Simply put, the most important job your brain does is not thinking. It is operating a body that has evolved from a small bug into something very, very complex. _1/2 Lecture: The brain is not for thinking. Barrett boldly overturns the typical preconception of the brain's 'most important mission' to open the book. The concept of 'body budget' refers to the role of predicting conditions inside and outside the body to control it for survival, essentially achieving allostasis. The first half of the first lecture concludes with the premise that "the idea of 'body budget' is the key to understanding how your brain works and ultimately how to live a healthier and more meaningful life for a long time." In the following seven lectures, we explore what makes the human brain special or not in a kingdom filled with marvelous brains, the best scientific explanations of the structure and functioning of the human brain, how the brain of a baby born into the world gradually transforms into an adult brain, how the brain operates by 'predicting,' and how different human minds can emerge from one brain structure. About living a free and fulfilling best life: What modern neuroscience tells us. The content of this short yet powerful book does not stop at scientific discoveries about the mechanisms of the brain. Barrett often asks for understanding as she temporarily sets aside her position as a scientist to confront real-world questions. She encourages us to think about what kind of humans we are or want to be in the social, cultural, and political realms where humans with brains actually live. The idea that 'we are waging war in our minds' is deeply embedded in many social institutions. In the economic field, investor behavior models clearly distinguish between rationality and emotion. In politics, there are leaders with clear conflicts of interest, such as those who have a history of lobbying in the industries they currently oversee, who believe they can make rational decisions for the public without being easily swayed by emotions. Beneath these arrogant thoughts lies the myth of the 'triune brain.' The brain is not three; it is one. To move beyond the inner battles that Plato spoke of, we need to fundamentally rethink what it means to be rational, what it means to take responsibility for one's actions, and even what it means to be human. _1 Lecture: The brain is one; discard the triune brain. For example, for a baby's brain to develop, appropriate physical and social stimuli are essential, and babies must learn to properly allocate their 'body budget' through caregivers (3 Lecture). Thus, poverty, which leads to a lack of stimulation and social neglect, is a formidable adversity. However, politicians have dragged their feet for decades without solving the issue of helping children escape poverty. Barrett firmly states that rescuing children from the tragedies of poverty and abuse is not simply a matter of 'quality of life.' Saving children right now is about preventing a greater tragedy and is therefore (if we exclude politics) 'much more financially effective.' It is no surprise that this vicious cycle reinforces negative stereotypes about people living in poverty. When poverty persists across generations in a particular group, society too easily blames genetics. However, it is highly likely that the brains of children in that group are being shaped by poverty. _3 Lecture: Young brains connect with the world on their own. In the 4th Lecture, the brain emerges not just as an organ that simply responds to stimuli but as a predictive organ that rewires itself. Here, Barrett mentions a long-standing unresolved issue: the concept of 'free will.' "The brain is a predictive organ. In other words, your actions are controlled by your memories and environment. Does this mean you have no free will? Who should be responsible for your actions?" Of course, this book does not settle the debate on free will. However, Barrett's perspective is clear. People are more responsible for their actions than they think. If the brain uses past experiences to predict and prepare your actions, then you have the opportunity (to some extent) to choose to change the way you predict. If the brain fine-tunes and prunes various predictions, automating certain behaviors, and as a result, you experience yourself and the surrounding world differently, then that is a form of free will or at least something that can be called free will, according to Barrett. This aligns with the perspective on 'human nature and responsibility' mentioned in the 1st Lecture. If we take these thoughts seriously, the foundations of society's outdated systems could change. If your brain is not simply reacting to the world but actively predicting it and can even change its wiring, then who should be responsible when you act poorly? It is you. (Omitted) Sometimes, we are responsible not because we did something wrong but because we are the only ones who can change it. _4 Lecture: Your brain predicts almost all your actions. The fact that humans are social animals may be so important that it is hard to grasp. Through our brains, we can vividly confirm this fact. Being a 'social animal' means we can share and regulate our body budgets with each other (5 Lecture). In other words, although invisible, our brains and bodies are strongly connected to the brains of others. Uniquely, humans use the tool of 'language' to regulate each other's body budgets. This makes it clear how profoundly our daily lives and health can be influenced by others and their words. It explains why verbal abuse is indeed violence and can cause physical harm to our bodies, as the evidence lies within the structure and mechanisms of the brain. The saying 'stress makes you gain weight' is no longer an abstract phenomenon. The existence of 'others and their brains' actually has a physical impact on managing your brain's body budget. Chronic stress is defined as the constant struggle in a sea of stress, accumulating a serious deficit in the body budget. This does more than make you miserable at the moment. Anything that causes chronic stress can gradually erode the brain over time, leading to physical illness. This includes numerous ways humans torment each other, such as physical abuse, verbal violence, bullying, and severe neglect. _5 Lecture: Your brain moves invisibly with other brains. In addition, 《Seven and a Half Lessons About the Brain》 addresses how humans come to have multiple minds, sometimes conflicting, and what guidance this gives us when facing different cultures and people (6 Lecture), as well as what empowers us to create customs, rules, and civilizations (7 Lecture). Following this journey, we will occasionally look into how the brain and the processes of managing the body budget and predicting play a central role in shaping your actions and experiences. Finally, at the end of this book, there is a section titled 'The Science Behind the Science,' which serves as an 'appendix that is not like an appendix.' It summarizes scientific details that the author could not include in the main text, including important content that goes deeper into each lecture topic, issues in the scientific community, and sources of witty expressions left by scientists. Unlike typical book annotations, it can be seen as 'another lecture' that is enjoyable to read in its own right. In short, this book aims to break down unfounded myths about the brain and reveal its truly important aspects, sharing what this means for us. Following the short and engaging seven and a half lectures, you will soon recognize deep-rooted myths like the 'lizard brain' and the so-called dichotomies of 'reason vs. emotion' and 'nurture vs. nature,' prompting you to reflect on how to act and judge as a truly 'brain'-endowed human.