Abstract

Despite traditional EEG signals being affected by physical activities like hand movements or facial expressions, and even perspiration, they have been considered indicators of consciousness for over a century and a half. 1Hz to 40Hz low frequency signals are assigned to human cognition, perception and emotion, no one asks, if key ionic brain signal leaks from cortex how brain carries out credible computation using ions? We challenge the 150-year belief that low-frequency neuron bursts are key to human consciousness; ions are diluted at 15 layers before reaching EEG probe. We argue that MHz electromagnetic signals govern key computing in the brain. In our study of 40 gastroenteric patients undergoing anaesthesia with propofol, we monitored transitions into and out of unconsciousness, comparing EEG with DDG signals. MHz bursts emit from all over brain scalp only at unconscious states tracked by BIS and disappear upon regaining consciousness. Strikingly, identical bursts appear in microtubule bundles of cultured hippocampal neurons, only when a neuron fires, so we attribute MHz bursts of anaesthetic patients to microtubule bundles in the neurons. We virtually created and simulated 15 layers between scalp and the cortex, to find that ionic signals (Hz to kHz) are disrupted but free to transmit, MHz signals partially transmit and primarily reflects back deep inside cortex, GHz signals are largely attenuated at small distance. Collectively, meninges create a 6–212 MHz gateway for critical brain signals from cortex to scalp partially and reflect back to cortex primarily. Anaesthesia may unlock this gate, leaking true MHz brain signals, until the meninges release transmitted anaesthetic molecules. The one-to-one match between single-neuron bursts and those in unconscious patients' foreheads suggests meninges gate’s 14 channel pathway to scalp, and positioning microtubules as the true neural correlates of consciousness.