Thalamic rhythms in the 25-40 hertz range that occur only when the subject is observably conscious or in REM sleep, disappearing in non-REM deep sleep. Experiments with electrical stimulation of the claustrum. Tracking (via EEG, etc.) synchronization of activity in multiple cortical regions during observed consciousness. Observed correlation between changes in cerebral energy energy consumption and the level of possible observational activity (via isolation techniques). And more. That consciousness is at least in part comprised by brain function seems very close to certain at this juncture.

Energy? I don't even know where to start. Maybe CERN...?