A Simultaneous EEG & High Temporal Resolution fMRI Study of Trial-by-Trial Fluctuations in Visual Evoked Potentials

Pierre LeVan¹, Benjamin Zahneisen¹, Thimo Grotz¹, Jrgen Hennig¹

This EEG-fMRI study investigates visual evoked potentials (VEP) using MR-encephalography (MREG), an fMRI technique with a high temporal resolution of 100ms. This allows the accurate estimation of the hemodynamic response function (HRF) to visual stimuli, as well as the removal of physiological artifacts. Trial-by-trial fluctuations of the HRF amplitude were correlated with VEP P1 amplitudes at the center of visual cortex, and with N1 amplitudes at the periphery. Moreover, small HRF delay differences consistent with the VEP were observed between P1- and N1-associated brain regions. MREG is a promising technique to study fast neuronal transients with a high temporal resolution.