Methods and Labs

State-of-the art brain imaging and stimulation techniques enable us to elucidate the contributions of specific brain regions and networks to the processes and disorders under investigation.

Using functional magnetic resonance imaging (fMRI), we investigate the activity and connectivity of brain areas under resting state conditions (resting state fMRI) as well as the responses to experimental stimuli, ranging from neutral images or sounds to pleasant touch and unpleasant pain stimuli. Quantitative magnetic resonance spectroscopy (q-MRS) allows us to determine the concentration of specific neurotransmitters that are of particular importance for the activity and communication of brain areas. In addition, voxel-based morphometry (VBM) provides us with important insights into the structure of the brain, for example the size of individual brain regions. Diffusion tensor imaging (DTI) allows us to examine the fiber connections between brain regions.

Functional near-infrared spectroscopy (fNIRS) is a non-invasive imaging method that measures changes in blood flow in the brain. It uses the special properties of near infrared light to determine the concentration of oxygen in the blood and thus indirectly the activity of nerve cells. fNIRS is a modern method in neuroscience to measure the activity of cortical, i.e. superficial, brain regions. Compared to fMRI, fNIRS is more mobile and allows its use in a variety of natural situations. . It even provides opportunities to test multiple people simultaneously, allowing the assessment of the synchronization of brain activity between individuals.

Transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS) are non-invasive neuromodulatory techniques that are based on the application of electrical currents to the scalp to modulate brain activity. In tDCS, a constant, low current is used, while in tACS an oscillating current is used. tDCS and tACS are used in clinical applications and in basic research to investigate the causal role of cortical brain regions. For instance, the prefrontal cortex can be stimulated to test whether it plays a significant role in emotion regulation.

Equipment:

MRI research is carried out on two research MRI scanners (Siemens Magnetom Prisma, 3 Tesla with 64-channel coil) at the RUB Research Department of Neuroscience (RDN) in Bochum and the Leibniz Institute for Work Research at TU Dortmund University (IfADo). In addition, there is access to 3-Tesla MR scanners at the University Hospital Knappschaftskrankenhaus Bochum and the University Hospital Essen through collaborations in the context of ongoing studies by professors Elsenbruch and Icenhour.

Two fNIRS devices (NIRSport 2 Wireless) and a stimulator with 4 channels (Neurocare) are in use at the Department of Social Neuroscience (Prof. Dirk Scheele).

In our experimental studies, we collect various psychophysiological measures that provide information about the activity of the autonomic nervous system and possible changes induced by emotional and cognitive processes.

Electrodermal activity (EDA) as an indicator of the activity of the sympathetic nervous system can be used, for example, to investigate emotional arousal patterns that are characteristic of fear conditioning. Changes in the heart rate and in heart rate variability measured by electrocardiography (ECG), as well as in blood pressure and respiration, offer insights into the complex interplay between mental processes and physiological reactions, which can be particularly pronounced in connection with psychological stress. The electrical activity of the stomach is also autonomously regulated and can be measured non-invasively using electrogastrography (EGG), which is particularly interesting in the context of gastrointestinal symptoms and altered eating regulation.

Eye tracking and pupillometry are used to map eye movements and changes in pupil size during the processing of emotional information and as part of cognitive processes. Finally, transcutaneous vagus nerve stimulation (tVNS) enables us to specifically and non-invasively modulate one of the central communication pathways of the autonomic nervous system, which can influence the functions of internal organs as well as our alertness and mood. Overall, we use these different methods in our studies to elucidate bodily physiological responses that are crucial for a better understanding of chronic stress-associated physical and mental illnesses.  

These physiological measurement parameters are complemented by the assessment of stress hormones and inflammatory mediators from saliva or blood samples, which we analyze in cooperation with the Institute of Medical Psychology and Behavioral Immunobiology at the University Hospital Essen. These endocrine and immunological parameters are particularly important for research into chronic pain in chronic inflammatory diseases.

Equipment:

Psychophysiological measurements using Biopac systems (Biopac Systems Inc.) are implemented at the research MRI and in the facilities of all departments. In addition, an MR-compatible eye-tracking system (Eye-Link 1000Plus, SR-Research), a transcutaneous vagus nerve stimulator (tVNS Technologies) and a SOMNOmedics system (SOMNOtouch NIBP) are part of the equipment shared by the groups of Professors Elsenbruch and Icenhour.

Various experimental pain models are employed in our research. Our expertise includes the application of thermal cutaneous pain stimuli to elicit exteroceptive pain responses, as well as of pressure stimuli to induce deeper muscle pain or interoceptive, visceral pain sensations. These protocols not only investigate pain responses within specific modalities but also facilitate direct comparisons across different modalities. We have also developed protocols integrating pain stimuli with aversive cues, such as unpleasant sounds, within sophisticated paradigms, allowing for a thorough exploration of cognitive and emotional pain modulation. Additionally, we study the effects of pleasant social touch, employing techniques like brush application. To capture responses across healthy participants and diverse patient cohorts, including chronic pain conditions, we use an integrated approach combining parameters from behavioral research, psychophysiology, brain imaging, psychoneuroendocrinology, and psychoneuroimmunology.

Equipment:

Several high-quality pain stimulation systems, including MR-compatible thermodes (PATHWAY model, Medoc, Advanced Medical Systems) and barostat systems (ISOBAR 3 device, G & J Electronics), are available in the research facilities of the Departments of Medical Psychology and Affective Neuroscience. We also have the equipment for quantitative sensory testing (QST). Several MR-compatible audio stimulation systems are available for studies implementing emotional acoustic stimuli (Amplifier mkll+S/N 2016-2-2-03, MR confon GmbH).