smitty777 writes "A new imaging technique called fEITER (for functional Electrical Impedance Tomography by Evoked Response) attempts to explain the process of slipping into unconsciousness. The fEITER is a portable device that creates 3D imagery based on evoked potentials measured hundreds of times a second. The interesting finding from these studies is that unconsciousness appears to result from a buildup of inhibitor neurons. From the article: 'Our findings suggest that unconsciousness may be the increase of inhibitory assemblies across the brain's cortex. These findings lend support to Greenfield's hypothesis of neural assemblies forming consciousness.'"