A closer look at MEG/EEG at OHBM 2016

BY nils muhlert

EEG (left, credit: D. Myers) and MEG (right, credit: NIMH)

Mapping the function of the brain is a key goal for OHBM and its members. Methods analysing electromagnetic signals, such as EEG and MEG, have moved us substantially closer to this goal.

EEG in particular has a long history in non-invasive imaging. Invented in 1929 by the German psychiatrist Hans Berger, its sensors track electrical activity over the millisecond range.
 
MEG, invented in the 1960s, maintains this temporal advantage but its sensors exploit the magnetic fields produced by electric currents. Since these magnetic signals are less distorted than the electric signals, they can be spatially located with greater certainty. Both tools have proved particularly useful clinically, and offer distinct advantages over MRI and PET for revealing the millisecond dynamics of physiological and cognitive processes.

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Fernando Lopes da Silva

OHBM 2016 will be highlighting the insights brought by electromagnetic imaging. New, less-experienced, and advanced users can quickly be brought up to speed at Sunday’s Educational Course. This comprehensive introduction, organized by Thomas Koenig & Laura Astolfi, covers the basics of field mapping, scalp field dynamics and source separation. For more advanced users, there will be discussions on assessing cortical connectivity with EEG/ MEG and integration with data from other modalities.
 
The highlight of the midweek sessions will be a keynote talk from Fernando Lopes da Silva (Tuesday), on using EEG/ MEG to examine functional and causal relationships in brain activity. This is complemented by talks on estimating brain connectivity using EEG/ MEG, and mapping the brain’s electrophysiological connectome (Wednesday morning).
 
Clinical uses of MEG, including presurgical evaluations for epilepsy, also feature prominently. For instance, clinicians and researchers will discuss ways to optimize MEG for language mapping, and ways to combine this information with language mapping data from functional MRI (Monday morning).
 
Integrating electromagnetic signals with other neuroimaging data is a hot topic throughout OHBM 2016. Experts will discuss using EEG-fMRI to examine cortical generators of spontaneous activity in preterm brains (Monday afternoon), mapping brain networks using simultaneous high density EEG and fMRI, and ways to combine EEG and functional near-infrared spectroscopy imaging data (Tuesday morning). 
 
Other talks will focus on using EEG to unravel the mysteries of memory (Tuesday oral sessions) and emotion regulation (Thursday morning). A whole host of poster presenters also promise engaging discussions on the use of EEG/ MEG across a wide range of topics.
 
The versatility of EEG and MEG is clear from the breadth of talks, discussions and posters on the topic. Connectivity and multimodal data fusion, as in many other areas of neuroimaging, remain hot topics. This program of events should provide inspiration for those already using EEG/ MEG, and for those looking for techniques to complement their existing neuroimaging programs. ​

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