J Braun1, M Patel1, C Keatch1, W Woods2, E Lambert1,3, T Kameneva3,4* 1School of Health Sciences, Swinburne University of Technology, Melbourne, Australia 2Centre for Mental Health and Brain Sciences, Swinburne University of Technology, Melbourne, Australia 3Iverson Health Innovation Research Institute, Swinburne University of Technology, Melbourne, Australia 4School of Engineering, Swinburne University of Technology, Melbourne, Australia
*Email: tkam@swin.edu.au
Introduction Mental stress is linked to cardiovascular disease, with signalling between central nervous and sympathetic systems influencing this relationship. However, our understanding of the association between central nervous and sympathetic systems during mental stress is limited.
Methods To assess the relationship between central nervous and sympathetic systems during mental stress, we simultaneously recorded magnetoencephalography (MEG) and muscle sympathetic nerve activity (MSNA), during the rest and stress conditions (10 minutes each), in healthy participants (n=13). During the rest condition, participants focused on a small cross on a screen in front of them, with no other stimuli delivered. The stress condition involved two parts (5 minutes each): non-vocal numerical based multi-source interference (MSIT) task, and color word-based STROOP task. The time allocated for responses during stress condition decreased over time and words "TOO SLOW" and "HURRY UP" were displayed when the allocated time lapsed.
MEG data for the brain response to stress and rest conditions were compared across delta (1-4Hz), theta (4-8Hz), alpha (8-13Hz), beta (13-30Hz) and low gamma (30-80Hz) bands. The mean neural activity power at each grid-point (averaged over all grid-points) was calculated and normalized over the whole brain, referred to as the neural activity indices.
