The human brain appeared on earth some five million years ago. It took just a few million more to fully mature, a mere blink on the geological time scale. Structurally, anatomically, the human brain has not changed much in about two hundred thousand years. It is the same brain used by the first Homo sapiens to walk the planet. But what has evolved is the mind. And it is this inner universe that has so mystified and beguiled us. The mind, together with the brain, forms the most complex system known to man. At the dawn of the 21st Century, we are slowly crossing the borders of this last frontier, so that we may understand better who we are why we create and invent, why our fears haunt us, our thoughts liberate us, where we prove our free will, our sense of self and express our inner voice. New mind-imaging techniques are giving researchers a tool for mapping the mind. Never before could we look this closely inside the living brain.

• David Suzuki