EEG can do real time imaging because the sampling rate is much better. EEG also requires fairly intensive data processing, but usually it can be done faster than fMRI because:
1. There is often less/different information in EEG. If you have 64 nodes, you will have less information to process than the >100000 voxels in fMRI.
2. There have been more reasons to look at EEG in real time. fMRI analyses are generally done with group level statistics, so usually you have to run many participants which takes weeks-months anyways.
>There isn't any existing tech to take surface data and "map" it to internal states
Eh, sort of. Algorithms like LORETA which do source reconstruction have been around for a while, and do an OK job of finding the general area of the source of a signal.
>There isn't any existing tech to take surface data and "map" it to internal states
Eh, sort of. Algorithms like LORETA which do source reconstruction have been around for a while, and do an OK job of finding the general area of the source of a signal.