Although your body enters a level of physical relaxation which is even deeper than sleep, in the float room your mind remains awake and dreamily alert, just above the threshold of sleep. Large areas of the brain are suddenly liberated from their normal workload of processing signals from the nervous system and sense organs. There is a sharp drop in the level of electrical activity of the brain (measured on an EEG) from the usual 20-25 Hz down to 4-8 Hz. EEG readings show a slow, rhythmic wave pattern known as the theta state.
This is where your learning abilities are at their highest and powers of visualisation and autosuggestion are greatly enhanced. Measurements of the brain waves produced by experienced zen meditators in deep satori show large amounts of theta activity across the cortex. For most people, however, the theta state is almost impossible to enter without falling asleep. In the float room, you enter this elusive state effortlessly and enjoyably, and stay in it for most of the float session.
EEG measurements on floaters show that the level of activity in the two hemispheres of the brain also becomes more balanced and synchronized. This can produce a subtle shift in awareness away from the normally dominant “left-brain” thought patterns (logical, linear, analytical, and detailed) towards the more intuitive, synthetic and large-scale thought modes of the “right-brain”. The tank does not inhibit the left hemisphere, but simply changes its role from one of dominance to one of partnership with the other hemisphere, enabling floaters to use all their mental powers.
In a study at Texas A&M University in 1982, Dr Thomas Taylor selected 40 well-matched subjects from 450 student volunteers and split them into two groups. Both groups underwent a series of 70-minute learning sessions using audiotapes.
One group (the control group) listened to the tapes while sitting on sofas in quiet darkened rooms.
The other group listened while floating in floatation tanks.
Taylor tested both groups on three levels of learning performance:
(1) basic memorization level
(2) application level (the ability to understand a concept and use it)
(3) synthesis thinking (the ability to put together several concepts and come up a new idea or an original solution to a problem).
A statistical analysis of the results showed that on the first level, floaters did better than the control group. On the second level, the gap between floaters and non-floaters widened. On the third level, the superiority of the floating group was greatest of all.
Taylor also recorded the brainwave activity of both groups while learning. He recorded several “Eureka events” – flashes of sudden insight or creative problem solving. He noted that these tended to occur in the deep theta state.