My research, in particular my analysis of time perception, suggests that consciousness correlates with a large scale quantum coherent state in the brain in the form of a Bose-Einstein condensate. Aside from the philosophical analysis which, I suggest, proves that this must be the case, there remains the problem of concrete evidence. How can we observe or measure large scale coherent states in the brain.

Hydrocephalus is a condition in which spinal fluid can become trapped in the centre of the brain. In very severe cases where the condition has gone undetected for a considerable period of time the brain can be forced develop around a large fluid filled space in an unusual way. In severe cases this can lead to a condition coined 'shell-brain'. The brain literally occupies a thin layer on the inside of the skull. Some sufferers of this condition can be highly functional.

This layer can be so thin that a light shone in one ear can be detected at the other. So, if we shine a fast burst of light through the brain in this way and measure the time lag between the burst of light and its detection then we can calculate the speed of the light. If the light passes through a BEC then it should be slowed down and this can be measured.

Is this feasible?