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Prof. Dr. Martin Diers

Flor H. EU - Europäische Union 230249: ERC PHANTOMMIND: Phantom phenomena: A window to the mind and the brain. 01/2009-12/2014.

Phantom experiences occur in almost all amputees but are among the least understood sensory phenomena. Recently changes in the representation of body maps in the brain were found to be related to phantom pain and it has also been demonstrated that there are great similarities between non-painful phantoms and bodily illusions such as the rubber hand illusion. This research has also shown that the brain does not process the physical but the perceived reality, which opens the door to manipulations of the perceived reality in basic research and the treatment of phantom pain. Behavioural intervention methods such as prosthesis, sensory discrimination or mirror training influence phantom limb pain and alter brain function. Thus, phantom phenomena are an excellent tool to study the neural basis of somatosensory and specifically bodily perception and this can lead to new treatment methods such as brain-computer interfaces or virtual reality applications for phantom pain and similar pain states. The aim of this project is (1) an exact assessment and analysis of the interrelationship of various phantom phenomena such as phantom limb awareness, painful phantom sensation, telescoping, prosthesis use and proneness to bodily illusions or plasticity of body image in a large sample of amputees, (2) the analysis of the neural correlates of these phenomena in small subgroups of amputees using functional magnetic resonance imaging as well as transcranial magnetic stimulation, (3) the analysis of determinants and neural correlates of bodily illusions in healthy controls to identify potential common neural mechanisms and (4) use of prosthesis and virtual reality training early after amputation in order to understand how manipulations of the body image and sensory feedback alter the development and the brain correlates of phantoms.

Diers M. : Seeing what you feel behind: neuronal correlates of seeing painful stimulation.. 04/2012-03/2014.

The body image, which is often taken for granted, is disrupted in patients with chronic back pain. Patients are unable to clearly delineate the outline of their trunk and state that they cannot “find it”. The back is normally a rather unknown area of the body. The reason is that in everyday life the own back is not seen. Although pain leads to an increased attention to their backs in patients with chronic back pain (CBP), it also changes the perception of the trunk. Despite there was no difference in reduction of pain intensity between healthy controls and patients with chronic back pain I showed in previous work that visual feedback during painful stimulation of the back led to reduced pain intensity ratings compared to visual feedback of the dorsum of the hand. However, the supraspinal mechanism behind pain reduction induced by seeing one’s own back is currently unknown. Therefore, we will use functional magnetic resonance imaging (fMRI) to measure brain activation in 20 healthy controls (HC) during painful electrical stimuli of the back while subjects receive visual feedback of a) the dorsum of the hand, b) the site on the back were the stimuli are applied and c) a video of a third person’s back. Participants will rate pain intensity during the measurement.

Zentralinstitut für Seelische Gesundheit (ZI) - https://www.zi-mannheim.de