WO YEARS AGO Leonie Koban, a member of Tor Wager’s lab, tested the effect of other believers on a subject’s experiences of pain. The researchers delivered a burning sensation to their subjects’ arms and asked them to rate how strong it was. The volunteers also viewed a series of hash marks representing how previous participants had rated their pain. For the same stimulus, the subjects reported feeling higher or lower levels of pain based on what they were told previous participants had felt.
Tests of the subjects’ skin conductance responses—involuntary changes in how the body is conducting electric-