Surge of neurophysiological coherence and connectivity in the dying brain.
Proceedings of the National Academy of Sciences of the United States of America August 27, 2013 Jimo Borjigin, UnCheol Lee, Tiecheng Liu et al.
During cardiac arrest, the mammalian brain can generate a transient surge of highly coherent gamma oscillations that exceed levels seen during conscious waking. In rats undergoing experimental cardiac arrest, continuous electroencephalography revealed a global increase in gamma power, coherence, and directed connectivity within the first 30 seconds after arrest, before the electroencephalogram became isoelectric. These gamma waves were tightly phase-coupled to theta and alpha waves. The findings suggest that near-death, the brain can paradoxically produce neural correlates of heightened conscious processing.