Brain -> Computer Music Interface

I ran across this video posted a while back on Hacked Gadgets regarding a research project being conducted at the University of Plymouth.

I am currently conducting research along the same lines but my concept for utilizing the EEG signal differs signifigantly. In this usage the computer is basically "playing along" with a live reading of the subjects mental state. This approach is intruiging (and seems quite enjoyable for the test subject) but I see the interpretation or judgement made by the programming as a major leap in assumption. The researcher seems to acknowledge this. Perhaps it was the only way to make the dynamic legible and fun. Amplifying the EEG readings and retaining a version to-scale of their raw form is what attracts me to the topic. The ability to flatly reference a commonly invisible/inaudible organic characteristic - and apply that characteristic to active expression. That seems useful.