Schematic representation of experimental design and procedure.
Panel (a) displays Manipulation procedure including the initial Pain Expectation rating, the measure of Pain Threshold, the administration of Sham Cream plus Verbal Suggestion and Pain Manipulation. In panel (b) are shown the Baseline, Pain and Placebo treatments in waking condition. In panel (c) are shown the same treatments administered after the hypnotic induction (Stanford Hypnotic Clinical Scale, SHCS). Treatments, within each participant, were administered in the same order in waking and hypnosis condition, but both conditions and treatments were counterbalanced across participants. Before administration of pain and placebo treatment, participants rated the level of pain expectation. Following each pain treatment, participants rated the intensity of experienced pain and distress sensation. In panels (b) and (c), for each treatment, are displayed acoustic probes (115 dB, 40 ms) delivered to elicit startle blink responses.