Abstract #0109

Negative BOLD & CBF Responses are Predicted by Natural Variations in Evoked EEG Response to a Median Nerve Stimulus in Humans.

Karen J. Mullinger¹, Stephen D. Mayhew², Andrew P. Bagshaw², Richard W. Bowtell¹, Susan T. Francis¹

¹Sir Peter Mansfield Magnetic Resonance Centre, School of Physics & Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom; ²Birmingham University Imaging Centre, School of Psychology, University of Birmingham, Birmingham, United Kingdom

The origins of the negative BOLD response (NBR) remain unclear. Here we use simultaneous EEG-BOLD-ASL recordings during sustained median nerve stimulation to interrogate the NBR. Significant negative correlations of BOLD/CBF with a boxcar model were found in ipsilateral S1. The magnitude of the negative BOLD/CBF responses in ipsilateral S1 were also correlated with the amplitude of somatosensory evoked potentials (SEP) that originated from contralateral S1. This region was more consistent with the site of the positive BOLD in response to the boxcar model in the opposite hemisphere. This study provides new evidence for a neural component underlying the NBR.