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NeuroCampus Aarhus/DNC guest talk: Risto Ilmoniemi

Academy Professor Risto Ilmoniemi, Department of Biomedical Engineering and Computational Science - BECS, Aalto University School of Science is viviting Aarhus and will give a guest talk

Info about event

Time

Wednesday 27 November 2013,  at 14:30 - 16:00

Location

Aarhus university Hospital, DNC Auditorium, Building 10G, Nørrebrogade 44, Aarhus C

Organizer

NeuroCampus Aarhus, CFIN, MINDLab

Risto Ilmoniemi: 

New Developments in MEG/EEG and Brain Stimulation Technologies

Abstract

The development of MEG and EEG technologies is aiming at a level where (i) the head is covered by a dense set of sensors, (ii) the noise level is close to fundamental limits, (iii) the locations of the sensors with respect to the brain can be accurately determined, and (iv) the conductivity distribution of the head is known in sufficient detail. In a parallel and related line of development, transcranial magnetic (TMS) and electrical (TES) stimulation are being further developed.

We are contributing to two aspects of the technological development. First, we have built a hybrid multichannel helmet-shaped MEG-MRI prototype capable of ultra-low-field MRI and MEG using the same sensors. The main benefit of measuring MEG and MRI with the same detectors is superior registration and thereby improved source localization accuracy and reliability. In addition, MRI at ultra-low fields offers unique benefits such as quiet operation, lack of projectile hazard and improved safety when people with metallic implants or cardiac pacemakers are studied. Conductivity imaging may also be possible with ultra-low-field MRI.

Second, we are developing methods for transcranial magnetic stimulation (TMS) combined with multichannel electroencephalography (EEG). We use so-called navigated brain stimulation (NBS), which allows very accurate targeting of the neuron-stimulating electric field. When the TMS-evoked EEG is recorded, one obtains direct measures of cortical excitability and time-resolved area-to-area connectivity. One can also monitor changes in excitability and connectivity in the course of treatment, medication, or rehabilitation.

The new technology will offer great opportunities for more sophisticated data analysis, including improved possibilities to take into account a priori information, the benefits of which will be more significant as the signals and geometrical data will become more reliable. The challenge is to develop algorithms and software to take advantage of the emerging technology. How should one separate signal from artifacts and noise? How should one register the coordinate systems of different modalities and merge high- and low-field MR images? How should one take into account the detailed conductivity structure if and when it will be available? How should one combine MEG and EEG data to solve the inverse problem? What are the ultimate limits of MEG/EEG and how will we reach them? How should brain dynamics be studied?

The guest talk will take place in the DNC Auditorium, AUH, Building 10G, Nørrebrogade, Aarhus C

ALL ARE WELCOME.