Part I. HOW WE HAVE BEEN, HOW WE HAVE CHANGED
INTRODUCTION: THE SPACES BETWEEN US
Consider, for a moment, our brains. Individual working units in the brain are called neurons. Some neurons are highly specialized to perform certain cognitive functions. Others are arranged in groups of varying size to accomplish more complicated tasks. Some are charged with storing things, and others with just passing information along. Neurons have excitable membranes, a unique cellular characteristic that allows them to generate and propagate electrical signals. When a neuron wants to act, it sends out a small signal, like an e-mail, to the parts of the brain with which it wants to connect. That signal, in order to get where it wants to go, must jump a series of small gaps, each called a synapse, that separate one neuron from another. A child's brain contains as many as 1,000 trillion synapses, but by adulthood age and decay pare that number back significantly to between 100 trillion and 500 trillion. What occurs in our synapses—in other words, in the space in-between—is a key determiner of successful brain function. So-called strong synapses pass messages—called action potentials—easily to the neurons around them. Where synapses are strong, they allow for the free-flowing transmission of energy from neuron to neuron that enables the vast range of human capability. Where synapses are weak, however, messages don't get through. A weak synapse drops the ball, so to speak.
Now, imagine a football stadium, ...