The effects of conditioned pain modulation on pain processing

This is a study using MRI to investigate the effects of conditioned pain modulation on pain processing. The purpose of this study is to further our understanding of the neural signalling during concurrent pain experiences in various locations of the body and to investigate potential differences between males and females.

This study will involve males and females who are 19 to 60 years of age, with no history of neurological injury or disease, and are otherwise healthy. It will consist of a single visit to the MRI facility at Queen’s University, divided into two segments.

In the first part, participants will undergo training in a simulated MRI environment known as the sham lab. Here, they will be introduced to two different heat stimuli, applied to their right hand and left calf, respectively. These stimuli will be individually tailored to each participant's pain sensitivity, ensuring tolerability. Participants will also receive training on pain rating scales and will complete questionnaires regarding general health information, mental health history, and MRI safety.

The second part will take place within the MRI system, replicating the setup from the sham lab. Participants will lie supine in the MRI machine with a mirror enabling them to view the pain rating scale and instructions during imaging runs. Throughout each run, spinal cord and brainstem images will be captured repeatedly. At designated points, participants will experience the heat stimulus either on their hand alone or on both their hand and leg. Clear guidance will be provided on what to expect, as well as when and how to rate their pain. The entire visit is expected to last approximately 2 hours.

Participants will receive a $40 honorarium to compensate for their time and expenses.