Joseph Le Doux believes that the synapses - the little spaces between the neurons in our brains - are the key to everything the brain does. They are the channels of communication by which we think, act, imagine, feel and remember. But synapses do more. They also allow interactions between mental processes, allowing us to remember the important stuff in life better than the trivial. What's more, synapses encode the essence of the individual, allowing us to be the same person from moment to moment, week to week and year to year. In short, the self is synaptic.