Neuroimaging of emotional activation: Issues on Experimental Methodology, Analysis and Statistics

Abstract

Objective: Emphasize on significant issues in neuroimaging methods, for a SAM group analysis, when studying the neuronal dynamics of the emotional activation induced by emotional visual stimuli. Efficient tackling of such issues can grant access to the localization ability in order to exploit the temporal resolution, with accuracy of a few milliseconds, for measuring the neuronal dynamics of emotional processing.

Methods: Magnetoenchephalography (MEG) was used to record brain activation during a mixed-picture paradigm. Neuronal sources of the MEG data were accessed using Synthetic Aperture Magnetometry (SAM), which provided continuous 3D images of cortical power changes. SAM images were spatially coregistered to anatomical scans. Both anatomical and functional images were spatially normalized into the Montreal Neurological Institute (MNI) template space. Nonparametric permutation methods unveiled the most significant regions among participants. Use of virtual channels revealed the neuronal dynamics for the main effects of the emotional stimulus.

Conclusion: A step by step high precision procedure for the coregistration and normalization required for SAM group analysis was presented and the basis of safety and cooperation with the participants on which the study was built was emphasized. Accurate localization of neuronal sources during emotional activation, induced by emotional visual stimuli can be accessed to exploit the temporal resolution, with accuracy of a few milliseconds, for measuring the neuronal dynamics of emotional processing.