Karen Julia Mullinger1, Claire M. Stevenson1, Susan T. Francis1, Richard W. Bowtell1
1Sir Peter Mansfield Magnetic Resonance Center, School of Physics and Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom
Haemodynamic and electrical responses may show unpredictable variations over repeated trials due to habituation or modulation of attention. Here we investigate if these effects can be measured in the somatosensory cortex using simultaneous EEG/fMRI. An average of 10 trials was required to ensure detection of the evoked response. With this averaging, attenuation of the BOLD response was observed suggesting habituation, but the evoked response did not reflect this. Variance of the evoked response was assessed and found to be similar to that of the baseline prohibiting the determination of whether the evoked response attenuates as observed for BOLD.