Understanding how the brain works is one of our greatest scientific quests. The challenge is quite different from other frontiers in science. Unlike the bizarre world of the very small in which quantum-mechanical particles can exist and not exist at the same time, or the mind-boggling expanses of time and space conjured up in astronomy, the human brain is in one sense an everyday object; it is about the size and shape of a cauliflower, weighs about 1.36 kg (3 lb) and has a texture like tofu. It is the complexity of the brain that makes it so remarkable and difficult to fathom. There are so many connections in the average adult human brain that if you counted one each second it would take you more than 3 million years to finish.
Faced with such a daunting prospect it might seem as well to give up and do some gardening instead. But the brain cannot be ignored. As we live longer, more and more of us are experiencing – or will experience – neurodegenerative conditions, such as Alzheimer’s disease. The incidence of psychiatric illnesses, such as depression and schizophrenia, is also on the rise. Better treatments for these conditions depend on a better understanding of the brain’s intricate networks.
More fundamentally, the brain draws us in because it defines who we are. It is much more than just a machine to think with. Hippocrates, the father of Western medicine, recognized this long ago: ‘Men ought to know that from nothing else but the brain come joys, delights, laughter and jests, and sorrows, griefs, despondency and lamentations.’ More recently Francis Crick – one of the major biologists of our time (see the biography) – echoed the same idea: ‘You, your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will, are in fact no more than the behaviour of a vast assembly of nerve cells and their associated molecules.’ And, perhaps less controversially, but just as important, the brain is also responsible for the way we perceive the world and how we behave within it. So to understand the brain is to understand our own selves and our place in society and in nature.
More than a machine
The brain is a complex and intricate information-processing mechanism – not just for cold, hard facts but for how we move, feel, laugh and cry. Neuroscientists are constantly gaining new insights into the inner workings of the brain.
But how to begin? From humble beginnings, neuroscience is now a vast enterprise involving scientists from many different disciplines and almost every country in the world. The annual meeting of the Society for Neuroscience attracts more than 20,000 (and sometimes more than 30,000) brain scientists. No single person – however capacious their brain – could possibly keep track of such an enormous and fast-moving field. Fortunately, as in any area of science, underlying all this complexity are some key ideas to help us get by. Here’s where this book can help.
How the book works
Within the following pages, leading neuroscientists and science writers will take you on a tour of 50 of the most exciting ideas in modern brain science, using simple plain English. To start with, in Building the Brain we will learn about the basic components and design of the brain, and trace its history from birth (and before), and through evolution. Brain Theories will introduce some of the most promising ideas about how the brain’s many billions of nerve cells (neurons) work together. Mapping the Brain will show how new technologies are enabling us to chart the brain’s intricate structure and activity patterns. Then, in Consciousness, we tackle the still mysterious relationship between the brain and conscious experience – how does the buzzing of neurons transform into the subjective experience of being you, here, now, reading these words? In the following chapters, Perception & Action and Cognition & Emotion, we will explore how the brain enables these important functions, both with and without consciousness. Finally, in the last chapter – The Changing Brain – we will explore some recent ideas about how the brain changes its structure and function throughout life in both health and in disease.
Approach the book however you like. Read it in order, or dip in and out. Each of the 50 ideas is condensed into a concise, accessible, and engaging ‘30-second neuroscience’. To get the main message across, there is also a ‘3-second brainwave’, and a ‘3-minute brainstorm’ provides some extra food for thought on each topic. There are helpful glossaries summarizing the most important terms used in each chapter, as well as biographies of key scientists who helped make neuroscience what it is today. Above all, I hope to convey that the science of the brain is just getting into its stride. These are exciting times and it’s time to put the old grey matter through its paces.
Mind-blowing
What’s happening inside your head? Imaging technology, genetics, chemistry and computing reveal our brains in increasingly more minute and technicolor detail.
