You can touch your chin with your eyes closed even though you can't see it and in fact haven't ever seen it. It's possible to lose this sense, too, which prett

You can touch your chin with your eyes closed even though you can't see it and in fact haven't ever seen it. It's possible to lose this sense, too, which pretty much rules out the idea that it's merely a mental model. People with nerve injuries may lose their ability to touch their chins with their eyes closed, as I just described.