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.