Brain Imaging and Pain: Analysis of Placebo Analgesia


This study examines the brain activation associated with placebo pain reduction.

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Parallel Assignment
    • Primary Purpose: Basic Science
    • Masking: Single (Participant)
  • Study Primary Completion Date: January 2015

Detailed Description

This study is a basic science study of the mechanisms of placebo analgesia in asymptomatic healthy individuals. Each participant receives a baseline pain testing session, followed by a conditioning paradigm that results in expectation of pain relief and conditioning. They then undergo functional magnetic resonance imaging during either placebo (conditioned analgesia) or baseline. To examine order effects and habituation, the participants also either undergo a repeated placebo or a repeated baseline. The primary dependent measures in the study are the fMRI determined regions of interest, in a network of brain areas associated with pain processing. The anticipated outcome of the study is the alteration of network connectivity between sensory, affective, evaluative areas of the brain associated with placebo. Because this is not a traditional clinical trial, there are not traditional efficacy criteria, rather the outcomes are changes in brain function from manipulations of patient expectation and classical conditioning.


  • Other: Placebo Instructions
    • There is no intervention in this study. It is not a Clinical Trial. The study is an investigation of the neural basis of placebo analgesia.
  • Other: Control condition
    • This protocol represents an investigation of the neural mechanisms of placebo analgesia. As such, it does not represent the traditional clinical trial design. Instead the “active” intervention is a placebo, and the comparison condition is a no-intervention control.

Arms, Groups and Cohorts

  • Placebo Comparator: Placebo
    • Asymptomatic control participants receive Natural History and Placebo instructions in a within-subject design. There are no patients, or active agents in this study. It is not a Clinical Trial.
  • Active Comparator: Control condition
    • The control condition represents a no-intervention, repeated baseline control, since the “active” intervention in this study is placebo.

Clinical Trial Outcome Measures

Primary Measures

  • Brain Imaging Results
    • Time Frame: 2 weeks from baseline
    • This outcomes represents the neural network underpinnings of the placebo analgesic response. It is the result of a network analysis using structural equation modeling of fMRI determined brain activations.

Participating in This Clinical Trial

Inclusion Criteria

  • at least 18 years of age – english speaking Exclusion Criteria:

  • pain condition – pregnant

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: N/A

Are Healthy Volunteers Accepted: Accepts Healthy Volunteers

Investigator Details

  • Lead Sponsor
    • University of Florida
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Official(s)
    • Michael E Robinson, Ph.D., Principal Investigator, University of Florida


Sevel LS, O'Shea AM, Letzen JE, Craggs JG, Price DD, Robinson ME. Effective connectivity predicts future placebo analgesic response: A dynamic causal modeling study of pain processing in healthy controls. Neuroimage. 2015 Apr 15;110:87-94. doi: 10.1016/j.neuroimage.2015.01.056. Epub 2015 Feb 3.

Robinson ME, Staud R, Price DD. Pain measurement and brain activity: will neuroimages replace pain ratings? J Pain. 2013 Apr;14(4):323-7. doi: 10.1016/j.jpain.2012.05.007.

Letzen JE, Sevel LS, Gay CW, O'Shea AM, Craggs JG, Price DD, Robinson ME. Test-retest reliability of pain-related brain activity in healthy controls undergoing experimental thermal pain. J Pain. 2014 Oct;15(10):1008-14. doi: 10.1016/j.jpain.2014.06.011. Epub 2014 Jul 3.

Letzen JE, Craggs JG, Perlstein WM, Price DD, Robinson ME. Functional connectivity of the default mode network and its association with pain networks in irritable bowel patients assessed via lidocaine treatment. J Pain. 2013 Oct;14(10):1077-87. doi: 10.1016/j.jpain.2013.04.003. Epub 2013 Jun 3.

Kisaalita NR, Robinson ME. Analgesic placebo treatment perceptions: acceptability, efficacy, and knowledge. J Pain. 2012 Sep;13(9):891-900. doi: 10.1016/j.jpain.2012.06.003. Epub 2012 Jul 31.

Kisaalita N, Staud R, Hurley R, Robinson M. Placebo use in pain management: The role of medical context, treatment efficacy, and deception in determining placebo acceptability. Pain. 2014 Dec;155(12):2638-2645. doi: 10.1016/j.pain.2014.09.029. Epub 2014 Sep 28.

Craggs JG, Price DD, Robinson ME. Enhancing the placebo response: functional magnetic resonance imaging evidence of memory and semantic processing in placebo analgesia. J Pain. 2014 Apr;15(4):435-46. doi: 10.1016/j.jpain.2013.12.009. Epub 2014 Jan 9.

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