Dr. Axel Thielscher
Phone: +49 7071 601-907
Fax: +49 7071 601-702


Multimodal Imaging using TMS and fMRI

Research foci: Our main focus is on the development and application of methods for electric field calculations for non-invasive brain stimulation (NIBS) techniques. This is complemented by research activities on the combination of transcranial magnetic stimulation (TMS) with functional MRI in collaborations to study human motor control and multisensory integration processes. With the relocation of Axel Thielscher to Copenhagen (Denmark), most of the research on sensorimotor integration is now performed in collaboration with colleagues in Copenhagen. However, we still have an ongoing collaboration with Dr. Marc Himmelbach (Hertie-Institute, University Clinics Tübingen) on the effector specificity of parietal brain regions during the performance of reaching and grasping movements. In collaboration with the former research group of Prof. U. Noppeney we used interleaved (or concurrent) TMS-fMRI to study multisensory integration processes. The examples on this website focus on the electric field calculations.

Comparing biophysical calculations with electrophysiological responses to TMS

During the last years, we have developed a software pipeline Opens external link in new window( that allows for the efficient generation of volume head meshes from individual structural MR scans. This makes a wider usage of realistic field calculations for TMS feasible, but also opens the question how well these calculations are actually suited to predict the electrophysiological responses to TMS. The project performed by Dr. Andreas Bungert focused on establishing the link between the estimated fields and the physiological stimulation effects on the motor cortex, e.g. by testing the effects of systematic coil rotations on both parameters.

Speeding up the calculations

Speeding up the field calculations for TMS would allow integrating them into commercial neuronavigation systems. This would substantially increase the acceptance of these novel methods by researchers who apply TMS in clinical and research settings in order to improve spatial targeting and dose estimations. The research of Dr. Andre Antunes focused on approximation methods that now reach update frequencies of the field estimates that are suitable for realtime visualization.

Extending the field calculations to transcranial direct current stimulation (tDCS)

We extended our field simulations to also cover tDCS. This work was carried out by Guilherme Bicalho and Dr. Andre Antunes. In tDCS, sponge or rubber electrodes attached to the head are used to pass weak currents through the brain. The adaptation of the SimNIBS pipeline to allow for tDCS simulations comprised the extension of the FEM calculations themselves as well as the modeling of the stimulation electrodes.
We are the reference site for MagVenture (Denmark) for interleaved TMS-fMRI.
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Last updated: Wednesday, 04.02.2015