I am doing a study to the effects of sustained attention on Situation Awareness, i.e. how well one perceives and understands the relevant information in their direct environment (in both space and time) and the ability to make predictions about the near future. I want to use EEG to measure the participants sustained attention by calculating the mean power in the Alpha frequency band, over two second periods.
I am in doubt however, over which channels I should calculate this average. Perceptual related brain responses usually occur in the occipital lobe and other more posterior located regions, but where do I draw the line? Are there some references that may support such a decision?