# Placebo or Nocebo Interventions as Affected by Hypnotic Susceptibility
## 2 Methods
### Experimental Design  
Two counterbalanced sessions, a week apart, were conducted for each subject, one with a placebo cream and the other with a nocobo cream. The following steps took place at each session:  
_1. Establish and rate the experimental stimulus intensity._ We measured the pain threshold and pain tolerance (see above), and the subject marked each for pain intensity on a visual analog scale (VAS). We then established the _experimental stimulus intensity_ (ESI) as halfway between the pain threshold and pain tolerance and delivered it once. We told the subject that this stimulus intensity would not change throughout the experiment. However, pain sensations may change according to experimental conditions, i.e., hypnosis or cream application. The ESI was then delivered six times and pain sensations were marked by the subject on a VAS for pain intensity. _2. Rate the expectation with hypnotic analgesia._ Subjects were asked to rate the expectation for pain reduction under hypnosis on a scale of 0 to 10, where zero means no effect and 10 means the maximum. _3. Produce expectations with the placebo/nocobo._ We rubbed the \"conditioning cream\" around the stimulating electrodes. We explained that this anesthetic (or sensitizing) cream has a clear and proven _physiological_ effect of decreasing (increasing) pain, which was to be compared with the _psychological_ effects of pain reduction under hypnosis. 4. _Rate the expectation with the placebo/noceb._ Subjects were asked to rate the expectation for pain reduction (or elevation) produced by the cream on a scale of 0 to 10. 5. _Produce conditioning to the placebo/noceb._ We surreptitiously reduced (or increased) the ESI to 70% (or to 130%) in order to produce conditioning. The current was decreased (or increased) in two stages: by 15% for 5 stimuli and another 15% for the next 5 stimuli. We informed the subject that the cream needed time to penetrate and we wanted to know when it became effective. At each stimulus, the subject reported whether a change in intensity occurred, but did not mark it on a VAS. 6. _Rate the conditioning of the placebo/noceb._ Subjects were asked to rate the expectation after conditioning for pain reduction (or elevation) produced by the cream on a scale of 0 to 10. 7. _Measure the placebo/noceb effect._ The ESI was repeated six times and pain sensations were marked on a VAS for pain intensity. 8. _Induce hypnotic relaxation._ Hypnotic relaxation was induced for about 8 min according to a well-established procedure, as detailed below [7,8]. 9. _Measure the effect of hypnotic relaxation after giving the placebo/noceb._ The ESI was repeated six times and pain sensations were marked on a VAS for pain intensity. 10. _Induce hypnotic analgesia._ Focused hypnotic analgesia was induced for about 8 min according to a well-established procedure, as detailed below [7,8]. 11. _Measure the effect of hypnotic analgesia after giving the placebo/noceb._ The ESI was repeated six times and pain sensations were marked on a VAS for pain intensity. 12. _Measure the effect of the placebo/noceb after hypnotic analgesia._ Subjects were instructed to exit the hypnotic state and were reminded that the anesthetic/stimulating cream was still effective. The ESI was repeated six times and pain sensations were marked on a VAS for pain intensity. 2. _Induction of Hypnotic Relaxation_  
Induction of hypnotic relaxation included the following:  
1. _Physical relaxation:_ \"you start to feel relaxed and loosen up, your feet... your legs... your knees... belly... shoulders... head... all your muscles are loosening up. You have a feeling of warmth, heaviness, and deep relaxation all over your body, you sit relaxed, calm\". 2. _A feeling of tranquility and restfulness:_ \"and although you are aware of my voice, you are now more aware of the feeling of tranquility, you feel calm and peaceful, as you continue enjoying the restfulness of not having to do anything in particular right now\". 3.