This trial aims to determine the effects and mechanisms (mediators and moderators) of brief training in mindfulness meditation versus clinical hypnosis on acute, experimental pain.

Participants (N=200 with complete data) will be healthy undergraduate students or community-based individuals. An experimental, randomised trial will be implemented, with participants randomly assigned to either five daily, 20-minute mindfulness meditation sessions or clinical hypnosis sessions. Repeated measures and experimental pain manipulation will be implemented. Aim 1 is to examine the effects of these two treatments on experimental pain outcomes. Aim 2 is to examine the moderators of these effects. Aim 3 is to determine the mediators underlying improved experimental pain outcomes. Results will refine theory and will inform the future streamlining of treatments to target those mechanisms shown to be of most critical importance.

Inclusion Criteria:

• 18 years of age or older;
• Able to read, speak and understand English.

Exclusion Criteria:

• Pregnancy, heart or vascular disease, Raynaud's disease, sickle cell disease, seizure disorder, high blood pressure, or diabetes;
• Experience of recurrent fainting spells;
• Report of a chronic pain condition;
• Use of alcohol and/or pain medication in the last 24-hours;
• Currently receiving psychiatric care;
• Problems with allergic skin reactions or excessive bruising;
• Previous participation in a cold pressor experiment.
• All participants will be asked to consume a fruit box drink prior to the cold pressor to prevent vasovagal reactions.

These exclusion criteria are standard when using a cold pressor task in a healthy undergraduate population and ensure safe procedures to mitigate any potential risks.

We will make available to interested researchers a data file containing the de-identified data used for each published article at the time that the article is accepted for publication. The data will be de-identified to remove any variables from which it would be possible to identify any individual participants. Specifically, we will create a data file that includes all of the variables used in any published article and a list of the variables in the data file (along with their variable labels) and email to investigators who request the data a copy of: (1) the published article (which will describe the source of the data); (2) the variable list/variable labels; and (3) a copy of the data set (as an SPSS.sav file).

The experimenter will remain blind to participant condition.