INTERACTIVITY was actually born in the nineteenth century — with the telegraph, certainly, but also and especially with clinical electricity, which involved planting electrodes on the faces of the human guinea pigs used in such ‘medical art’ as practised by Dr Duchenne de Boulogne. The recent Duchenne exhibition at the Ecole de Beaux-Arts, Paris, aimed no less than to ‘rehabilitate’ Duchenne’s work, though this La Saltpetriere Hospital photographer was no more than an ‘expressionist of the passions’ for whom his patients’ faces were only ever laboratory material that enabled him to practise ‘live anatomy.’

– Paul Virilio, “A Pitiless Art” in Art and Fear

You can look at some of those photographs here. They are incredibly disturbing and so you should be aware of that.