In each case, he focuses their attention on a card trick he performs using his left hand, which they grasp with their right hand. With his right hand, the magician removes the victim's watch without their feeling it. All the victims are amazed when he returns the watch they never realized was missing. Clearly, at any one moment our attention focuses on only a limited aspect of everything we are experiencing. Researcher Tony Dickenson conducts a laboratory experiment assessing research participants' experience of pain. In one condition, the participants receive a tablet (actually a sugar pill) that they are told will make them more sensitive to electric shock. Results indicate that they report pain even at low levels of shock. In a second condition, participants are told that the tablet is a painkiller. In contrast to the first groups, they are able to tolerate significantly higher levels of shock. Expectations, concludes Dickenson, play a significant role in our experience of pain.