A connectome is a map of connections between a brain’s neurons.

In addition to this neuronal definition, there are other meanings of “connectome” that substitute brain regions or neuron types for neurons. The regional connectome is the one currently being mapped by the Human Connectome Project using MRI. A neuronal connectome is far more complex: yours contains a million times more connections than your genome has letters. Finding the complete neuronal connectome of a human brain is one of the greatest scientific and technological challenges of all time. The term “connectome” was coined in 2005.

You are your connectome.

This expresses the idea that your personal identity is encoded in the pattern of connections between your neurons. If this hypothesis is true, then any kind of personal change is ultimately about changing your connectome.

The four R’s

The brain is naturally endowed with four mechanisms of connectome change:
Reweighting means changes in the strengths of synapses.
Reconnection is the creation and elimination of synapses.
Rewiring is the creation and elimination of neural branches.
Regeneration is the creation and elimination of neurons.