Developing guidelines to improve semantic interoperability in spatial database management and geoinformatics in Slovenia.

Description:

Neurovascular coupling (NVC) is the basic mechanism of providing energy to active brain areas. To study the NVC one requires simultaneously acquired data from two brain imaging modalities. In our project, we will develop and use a system that will combine two non-invasive brain imaging modalities; functional near-infrared spectroscopy (fNIRS) and magnetoencephalography (MEG). fNIRS estimates cortical hemodynamic activity by measuring changes both in oxy- and deoxyhemoglobin concentration. MEG determines activity within the cortex based on the measurement of magnetic field near the head. Standard MEG systems use the liquid helium for cooling the superconducting SQUID magnetometers, but in this project we will use the novel optically pumped magnetometers (OPM). MEG based on OPMs (oMEG) do not need cooling with cryogenics, therefore they can be moved during measurement, same as fNIRS optodes. This opens a plethora of new applications to study the NVC, where the subject’s movement is required. Until recently, the only combination of modalities that allowed movement was electroencephalography (EEG) and fNIRS. MEG has a major advantage over EEG, it has higher spatial resolution, since its inverse solution is more accurate. fNIRS optodes attached to the head do not require any electronics and its housing can be paramagnetic, therefore they do not interfere with the MEG sensor’s operation; this was shown in our preliminary results.

The combined MEG-fNIRS system will consist of three crucial parts: fNIRS optodes, OPMs and a sensor holder, which will have holes for both type of sensors and will attach them directly to the subject’s head. The sensor holder will be 3D printed for each subject separately; the model will be built by extracting the outer points of the subject’s head magnetic resonance image (MRI). The goal of this study is to develop the methodology of assessing the NVC, therefore we will use this system to measure several scenarios. We will simultaneously measure with both modalities paradigms that will include single sensory tasks, resting-state and also multiple sensory tasks, which will simultaneously induce response in both the visual and motor part of cortex. To assess the NVC, we will compare and combine the measurements made with both modalities using various computational methods: cross-correlation and spectral analysis; calculating the source reconstruction; calculating the functional connectivity.

This project will be performed in a collaboration between research groups from three core organizations: University of Ljubljana (UL) with Institute of Mathematics, Physics and Mechanics (IMFM) as a Co-Investigator, Physikalisch-Technische Bundesanstalt (PTB) and The Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences (IBBE PAS). Each group has its own strengths, PTB has all the infrastructure and knowledge to perform the MEG measurements and IBBE PAS to perform fNIRS measurements. UL and IMFM have great experiences working with different neuroimaging datasets, their knowledge will be used to perform important calculations on the measurements to assess the NVC.

Main goals:

The goal of the project is to develop a methodology and analysis procedures for simultaneous imaging of neuronal and vascular activity of the brain during everyday activity such as tasks involving multiple sensory inputs and subsequent motor activity.

Project work packages:

1. Whole head fNIRS and oMEG imager
2. Design of close to real-world setting for subject studies
3. Subject studies
4. Quantitative analysis
5. Dissemination and management