Continuing Jean-Pierre Henry’s argument, Hugues Duffau shows that the brain’s plasticity, its permanent capacity to reorganize itself to adapt to circumstances, ensues from the fact that it is an extremely complex system, all of whose parts function interactively, by processes into which he affords us some insights here. Accordingly, Duffau addresses the very widespread idea that each area of the brain corresponds to a given function (movement, language, memory, emotion etc.), a theory known as localizationism. That idea, he asserts, is refuted by the observation of the chain reactions that connect all the parts of the brain that become activated, bringing into play that synaptic plasticity so specific to the human brain, which, incidentally, distinguishes it fundamentally from what is called Artificial Intelligence.
The author, a famous neurosurgeon, is certainly well placed to show, for example, that the ablation of a cerebral lesion cannot be performed without respecting the entirety of the dynamic neuronal network that is unique to each person and constantly evolving — which, to reiterate, is not the case with machines. He reports on the progress achieved in the understanding of the anatomy and highly complex functions of the brain, since it is now possible to map these with ever-increasing accuracy and, where necessary, repair them. Lastly, he alerts us to the risks inherent in artificial neural networks — a pale copy, in his view, of human neuronal networks — which could ultimately result in a deterioration of the neuro-plasticity of the human brain.