Neurofeedback during acute pain using real-time functional Magnetic Resonance Imaging (rtfMRI)

Real-time functional Magnetic Resonance Imaging (rtfMRI) is a tool for neurofeedback research and treatment. Based on the principles of classical biofeedback this method provides the opportunity to manipulate cortical regions of interest (ROIs) by cognitive strategies. Since it is possible to manipulate the anterior insular cortex (aIC) by rtfMRI, we are interested in the effects of downregulation of aIC activation during pain. Nine participants (5m, 4f, 25±3.0 yrs) received a functional localizer characterized by alternating blocks of pain stimulation (30 s heat pain stimulation via a thermode placed at the lower dominant forearm, NRS 7/10) and no stimulation without any visual feedback. To downregulate aIC activation, participants were instructed to decrease a gradually processing yellow line occurring on a black (instruction to keep yellow line constant, no pain stimulation) or blue (instruction to decrease yellow line, painful stimulation) background. Pain ratings were obtained after localizer and downregulation. Functional images were acquired on 3T whole body scanner with 32-channel head coil. Echo-planar imaging (EPI) sequences are used with TR=1.5 s, matrix size 64×64, TE=39 ms and slice thickness 3mm. Real-time data were processed with Turbo-Brain Voyager with a ROI selected by significantly activated voxels in the aIC after functional localizer. Off-line analysis was performed using BrainVoyager QX. The preliminary results show that the aIC is robustly activated during the functional localizer. When downregulating aIC, an increase of activation in the region of interest was observed. Pain intensity decreased by 29.0% to 32.0% when downregulating aIC. Our results show that the experimental manipulation of aIC is reflected in a decrease of pain perception. Interestingly, dowregulation of aIC was associated with an increase of BOLD-responses. This raises the question if the aIC plays a superior role in cognitive regulation mechanisms.