Detection of activity from the amygdala with magnetoencephalography

Combining excellent temporal resolution with accurate source localization is a challenge for brain imaging studies in humans. In this domain, showing evidence for the contribution of deep brain structures to magneto-encephalographic (MEG) signal may represent an important step. The amygdala, is an example of such structure that is essential for social cognition and emotional processes. To date, MEG studies have been mainly focused on cortical activities. Under the impulsion of Line Garnero, we tackled the challenge of detecting the activation of deep brain structures with non-invasive electromagnetic brain imaging methods and developed a new method to localize amygdala sources. Here, we first review amygdala structural and histological properties that argue in favour of the detection of its activity with MEG. Then we present a simulation study of amygdala contribution to MEG signal. This study was based on an original anatomical segmentation technique, which allowed distributing sources within the amygdala volume of each subject. Finally, we present preliminary data from a face perception experiment where amygdala activity was examined with this new distributed source imaging method. (C) 2011 Elsevier Masson SAS. All rights reserved.