I have a set of data acquired using a low-cost EEG system with only 8 electrodes. The electrodes were placed over Fp1, Fp2, F3, F4, C3, C4, Fz & Cz. Using 'prepare' option the 3D location of the electrodes were specified and mapped over 2D plane (figure attached). My question is how to 'create image' from this montage to run statistical analysis? If I simply run 'create image' and look at the resultant images after 2nd level analysis, the covered brain area looks not right. I ran for both 'interpolated' and 'masked' and the images are attached. Perhaps the image that is created using 'masked' is correct and I should just ignore the part of the brain that is on the back of my electrodes? 

In another note. How can I focus my statistical analysis on only one electrode or the mean of a set of electrodes? Very many thanks.

Greetings :-)

Amir