Six wild ideas for perpetuating your mind

The quest for cognitive immortality continues. Have you ever thought about what makes you? Science assures us it has everything to do with the three-pound organ between our ears, with its billions of neurons and trillions of delicate connections. But it's a lot trickier to explain why we have a sense of self-awareness or to pin down precisely where that first memory of Mommy actually resides. As we age, we forget most of what we've experienced, yet there's still undeniable continuity: At 30, or 50, or 70, you will still be you. To preserve that elusive continuity of self, some far-thinking technologists are working on ways to keep your brain going--even beyond death.