The human brain is the most complex entity we know of. It contains at least 90 billion neurons (nerve cells). Each of these is a complex information-processing device in its own right and interacts with about 1,000 other neurons. Understanding this degree of complexity is a daunting task.
Our understanding of the human brain is still in its infancy. The identification of the neuron as the basic building block of the brain occurred only 100 years ago. At first, progress depended on the study of damaged brains. It is only in the last 25 years that it has become possible to see brain structure and function in healthy volunteers. The remarkably detailed images that emerge from brain scanners, with their brightly coloured blobs, have had a dramatic impact. Human brains have become the image of choice for the media, attached to articles about ‘What our brains can teach us’ or ‘Contours of the mind’.
Brain research is beginning to attract big money. The Brain Activity Map project is expected to receive $3 billion from the US Government over the next ten years. The hope is that investigating the human brain in exquisite detail will have a similar pay-off to that achieved by the human genome project and will lead to progress in understanding mental disorders, such as autism and schizophrenia.
One of the most exciting features of research on the human brain is that we confront deep philosophical questions. Minds depend on brains. Without brains we could not think, or feel, or imagine. But we still feel uncomfortable with this identity. Am I simply the product of electrical activity in my brain? How can subjective experience emerge from brain activity?
Our theories about how brains work remain very primitive. Some people think that an insoluble conundrum arises because the human brain is trying to understand itself. Surely something complex can only be understood by something even more complex? I believe that this problem is more apparent than real. Here’s why. One of the glories of the human brain is that it enables us to share our thoughts. Our understanding is built on the thinking of our predecessors as well as our contemporaries and far transcends the abilities of any single brain. We pay too little attention to these effects of culture and collaboration.
Sophisticated network
The brain is fired up by a network of 90 billion neurons. Neuroscientists are only just beginning to discover how their activity relates to what happens in our minds.
Consider another highly social animal, the bee. The brain of a bee weighs 1 milligram and contains a mere million neurons. Yet this tiny brain enables bees to learn about the world and communicate using their waggle dance. Even more impressive is what bees can achieve through collaboration. From the reports of scouts, a swarm of bees can make a group decisions about the best site for a new nest.
Recent studies suggest that the way the bees interact to make decisions closely resembles the way neurons in the human brain interact to make decisions. This comparison gives us a feel for the dramatically enhanced abilities of the human brain compared with the bee brain. But it also instils in me a sense of wonder about what humans can achieve as a group.
A group of bees working together can achieve abilities resembling those of a single human brain. Imagine an entity containing the power of multiple, interacting human brains. We create such a system whenever we interact. And the best example of the power of such a system comes from the practice of science. It is through the practice of science that we will be able to unravel the mysteries of the brain. This book shows how exciting this journey will be.