Working in pairs, students explore how vision can alter a person's experience of the world - and, in this case, bodily sensation. A student sits at a table, one arm hidden from sight, and gazes at a corresponding artificial forearm and hand on the table. The tester strokes both hands (real and artificial) simultaneously. After a minute, which hand seems like the real one?
This somatosensory illusion illustrates how our brain creates our body image and sense of self on a moment-to-moment basis from incoming sensory information. Not everyone will experience this in the same way but many will believe the artificial hand is the real one.