Karen J. Mullinger1, Jade Havenhand1, Richard W. Bowtell1
1Sir Peter Mansfield Magnetic Resonance Centre, School of Physics & Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom
Electroencephalography data recorded during simultaneous functional magnetic resonance imaging are compromised by large artefact voltages. The pulse artefact (PA) is particularly troublesome because of its variability and persistence after artefact correction. By isolating the effects of the different putative sources of the PA (pulse-driven head rotation, Hall voltages due to blood flow and scalp expansion) we identify the main contributions to the PAs amplitude and variance. The results indicate that the dominant source of the PA is pulse-driven head rotation with the Hall voltages causing the largest variation in the PA across cardiac cycles.