Abdelmalek Benattayallah1, Nino Bregadze2, Aureliu Lavric3
1Physics, Peninsular MR Research Centre, Exeter University, Exeter, Devon, United Kingdom; 2School of Psychology, Exeter University, Exeter, Devon, United Kingdom; 3School of Psychology , Exeter University, Exeter, Devon, United Kingdom
We examined the effect of the number of EEG electrodes on the fMRI image quality, by employing a simple validation procedure. Each participant performed the same cognitive task in two runs during the same scanning sessions, wearing in one run a 32-electrode EEG cap and in the other run a 64-electrode EEG cap. fMRI activations in response to the experimental conditions in the task were contrasted within each run and across runs. Statistical analysis of the fMRI data revealed that overall there was adequate correspondence between the activations in the 32-electrode run and the 64-electrode run. Of the 13 regions that contained clusters of statistically significant differences in activation (nogo > go or go > nogo), 10 contained such clusters in both runs, 6 in the nogo > go contrast and 4 in the go > nogo contrast.