“Belief in the absence of illusions is itself an illusion. “
-Barbara Grizzuti Harrison
The rubber hand illusion is more than a vaguely creepy parlor trick. It’s a window into relationship between our mental and physical self-conception.
During the illusion, a participant’s hand is hidden, and a rubber hand positioned so that it appears as her own. She knows that it’s fake—but when both hands are stroked simultaneously, what’s seen and felt becomes blurred.
Suddenly the rubber hand literally feels like it belongs to her. Consciously she knows it’s not true, but that doesn’t matter. Threaten the fake hand, and people under the illusion’s spell respond as if their own hands were threatened.
Scientists have now shown that the hidden hand’s temperature drops during the illusion: its effects aren’t simply mental, but physical as well, and could even hint at as-yet-unknown processes of disease.
Also, on TEDtalks, Vilayanur Ramachandran tells us what brain damage can reveal about the connection between celebral tissue and the mind, using three startling delusions as examples.