> I've since found tricks that can make the world blaze up again in about fifteen seconds, and the effects last for hours. For example, if I have a group of students who are feeling fairly safe and comfortable with each other, I get them to pace about the room shouting out the wrong name for everything that their eyes light on. Maybe there's time to shout out ten wrong names before I stop them. Then I ask whether other people look larger or smaller – almost everyone sees people as different sizes, mostly as smaller. 'Do the outlines look sharper or more blurred?' I ask, and everyone agrees that the outlines are many times sharper. 'What about the colours?' Everyone agrees there's far more colour, and that the colours are more intense. Often the size and shape of the room will seem to have changed , too. The students are amazed that such a strong transformation can be effected by such primitive means – and especially that the effects last so long. I tell them that they only have to think about the exercise for the effects to appear again.^[Johnstone, Keith. <i>Impro: Improvisation and the Theatre</i>. London: Eyre Methuen, 1981.]