Understanding how the brain works is almost certainly the
most challenging scientific problem of our time. How can three
pounds of tissue perform mental feats that outstrip the ability
of the world’s most powerful computers while consuming less
energy than a dim lightbulb? Answering this question is the goal
of neuroscientists, who study it at many different levels. Much of
our current knowledge about how the brain works comes from
studying other species, ranging from worms or fruit flies up
to mammals like mice, rats, and monkeys. While this research
has given us many important insights, most of us ultimately
want to understand how the human brain works, and there are
many aspects of the human mind that simply can’t be studied in
nonhuman animals: if we want to understand how humans think,
we need to study humans.
This book will tell the story of how a set of new technologies
has given us the ability to study how the human brain works
in greater detail than ever before. These tools are known as
neuroimaging methods, because they allow us to create images
of the human brain that show us what it is made of (which we
refer to as its structure) and what it is doing (which we refer to
as its function). One tool in particular has revolutionized our
ability to image the brain: magnetic resonance imaging (MRI).