Stephen Downes

The story is in the headline, and the details revolve around a mechanism called long-term potentiation (LTP) which supports Hebbian learning. "We now know that this is not the case: rather than setting like a piece of clay placed in a mould, the brain remains instead like a piece of putty, on which each new experience makes a lasting impression. This phenomenon, referred to as synaptic (or neural) plasticity, involves reorganization of the connections between nerve cells, and is arguably the most important discovery in modern neuroscience."