What We Cannot Know: Explorations at the Edge of Knowledge

by Marcus du Sautoy

That the connectivity of the brain could be the key to consciousness has led to the idea that my ‘connectome’ is part of the secret of what makes me ‘me’. The connectome is a comprehensive map of the neural connections in the brain. Just as the human genome project gave us unprecedented information about the workings of the body, mapping the human connectome may provide similar insights into the workings of the brain. Combine the wiring with the rules for how this network operates and we may have the ingredients for creating consciousness in a network. The connectome of the human brain is a distant goal, but already we have a complete picture of the wiring of the neurons inside C. elegans, a one-millimetre-long brainless worm with a noted fondness for compost heaps. Its nervous system contains exactly 302 neurons, ideally suited for us to map out a complete neuron-to-neuron wiring. Despite this map, we are still a long way from relating these connections to the behaviour of C. elegans.

C.elegans