Douglas Gordon, 30 Seconds Text (1998). The viewer enters a darkened room and a light abruptly comes on. After 25-30 seconds the light is just as abruptly extinguished. During that brief interval the viewer can read the following haunting text:

In 1905 an experiment was performed in France when a doctor tried to communicate with a condemned man’s severed head immediately after a guillotine execution.

“Immediately after the decapitation, the condemned man’s eyelids and lips contracted for 5 or 6 seconds. I waited a few seconds and the contractions ceased, the face relaxed, the eyelids closed halfway over the eyeballs so that only the whites of the eyes were visible, exactly like dying of newly deceased people. At that moment I shouted “Languille” in a loud voice, and I saw that his eyes opened slowly without twitching, the movements were distinct and clear, the look was not dull and empty, the eyes which were fully alive were indisputably looking at me. After a few seconds, the eyelids closed again, slowly and steadily.

I addressed him again. Once more, the eyelids were raised slowly, without contractions, and two undoubtedly alive eyes looked at me attentively with an expression even more piercing than the first time. Then the eyes shut once again. I made a third attempt. No reaction. The whole episode lasted between twenty-five and thirty seconds.”

…On average, it should take between twenty-five and thirty seconds to read the above text.

There is a nice account of this work here, too.