Control over brain activation and pain learned by using real-time

functional MRI

R.C. deCharms, F. Maeda, G.H. Glover, D. Ludlow, J.M. Pauly, D. Soneji, J.D.E. Gabrieli, and S.C. Mackey

By Jennifer Wong

Introduction

Can learn control of autonomic measures – heart rate, skin conductance- and EEG rhythms

Pain perception affected by placebo effects, anticipation, attention

Subregions within rostral anterior cingulate cortex (rACC) are involved in pain perception

Hypnosis and placebos alter rACC and reduce pain perception

Broodman Area: 32/24

Introduction

Real-time fMRI measures localized processes as they occur

Research Question

Can subjects learn to control the brain's system, and whether learned control over rACC activation would alter pain perception in healthy subjects and patients with chronic pain?

Hypothesis

Learned manipulation of rACC using real-time fMRI leads to decreased effects of pain perception

Methods

healthy community volunteers-20 Males, 16 Females

Chronic pain- 8 Males, 4 Females

peltier thermode on left palm

Individually selected temperatures with 7/10 pain rating

Strategy instructions1. Attention. Attend toward perceived stimulus vs. away from it.

2. Stimulus Quality. Perception as neutral experience vs. tissue damaging , overwhelming

3. Stimulus Severity. Perceive stimulus as low or high intensity

4. Control. Attempt to control painful experience.

Methods

Localizer scan, 3 training runs, post-test run Chronic pain patients chose when to end scanning

Training/ post-test runs Training rates stimulus after scan completed Post-test rates stimulus immediately after receiving

pain

Methods

Experimental: continuous video depicting activation, and scrolling line chart -% BOLD signal change over time (s)

• Control:1. Pain only- effects of repeated practice2. Behavioural training, 2x longer, overt

attention on pain 3. Shown a different region of the brain 4. rtfMRI of previously tested subject's rACC

• Patient control: autonomic biofeedback – told to control skin conductance, Heart rate, respiration

Results

A: change in activation comparing last to first training session

B: post-test compared with first training session

Results

Control over fMRI bold activation in rACC increased significantly

Control over Pain increased significantly

Results

MPQ: Mcgill pain questionaire VAS visual analogue scale 1-10:

Discussion

• rACC: important for pain perception and regulation • Associated with cognitive processes: attention, emotion, task

difficulty, motor control

• Chronic pain patients need to be able to see functions of brain to control

• Stronger pain control -> greater likelihood of successful recovery

Discussion

Limitations: subjects engaged brain regions associated with rACC

o placebo effects are mediated in part by brains control system

o Pain matrix involved with processing: ACC, somatosensory cortices, insula, thalamus

o Pain anticipation

Future Studies

- Long term pain treatment

- Type of patients show greatest response

Take Home Message

• real-time fMRI was used to guide training to control rACC

• rACC: subregions involved with mediating conscious pain perception

• Increased Activation of rACC decreases pain perception

• Experimental subjects (rtfMRI) decreased pain significantly more compared to control subjects

My Opinion

Strengths Weaknesses

• Easy to follow instructions in procedure

• Good use of images and graphs

• Interesting topic

• Hard to understand the details in the statistical analysis and results

• Small sample size of chronic pain patients