For many years, it has been speculated that consciousness and cognition could be based on quantum information \cite{sep-qt-consciousness} which opposes the view that quantum coherence, the primary basis of quantum computing \cite{nielsen_chuang_2010}, cannot survive in complex biological systems \cite{Koch_2006,Tegmark_2000}. However, recent findings in photosynthesis \cite{Engel_2007,Collini_2010,Scholes_2017} have challenged this view suggesting that only long-range quantum coherence between molecules can account for its efficiency in light-harvesting. Here, we investigated if long-range quantum coherence may also play a decisive role in brain function. We found, surprisingly, that the cardiac pressure pulse evoked zero-quantum coherence (iZQC) \cite{Warren_1998} which were by a magnitude higher than theoretically expected. From this finding, we concluded that the underlying physiological process is - cautiously speaking - of an unknown macroscopic non-classical kind. The process reveals its importance by its temporal appearance; during consciousness it is highly synchronized with the cardiac pulse, while during sleep, no or only sporadic iZQC could be detected. These findings suggest that this non-classical phenomenon is most likely a necessity for consciousness.