Beta-[13-30Hz]- Waking rhythm: The brain is focusing on the word outside itself, or dealing with concrete specific situations.
Alpha[8-12Hz]- These waves are often present when the brain is alert but unfocused. Most people generate alpha waves when their eyes are closed. They are frequently associated with feelings of relaxation and calmness
Theta [4-7Hz] -As calmness and relaxation deepen into drowsiness, the brain shifts to slower, more powerfully rhythmic waves. Everyone generates theta waves at least twice per day: in those fleeting instants when we drift from conscious drowsiness into sleep and again when we rise from sleep to consciousness as we awaken. Accompanied by unexpected, unpredictable dreamlike vivid mental images(hypnagogic images)
Delta[.5-4Hz]- Cycling at an extremely slow frequency, delta rhythms are produced when people are deeply asleep or otherwise unconscious.
Akira Kazamatsu and Tomio Hirai analyzed EEG test of Zen monks going into deep meditative states. The study showed that as the monks went into meditation they passed through four stages: the appearance of alpha waves, an increase of alpha amplitude, a decrease of alpha frequency and finally the production of long trains of theta waves. Interestingly, the four states “were parallel with the disciples’ mental states. The more meditative experience a monk had, the more theta he generated(i.e., those monks who had more than twenty years of experience generated the greatest amounts of theta waves) and even in the depths of theta, the monks were not asleep but mentally alert.
Could it be that floating increases and facilitates the production of theta waves?
Research indicates that this is indeed true. A study by Gary S. Stern(Associate Professor Psychology- U of Colorado at Denver) found that ”the significant effect of floating… indicates that individuals who had floated in the isolation tank for one hour significantly raised their theta level.” Another larger controlled study by Professor Thomas E. Taylor(Texas A&M) analyzed the effects of floating on severable types of learning abilities, comparing floaters with people in a relaxed state in a dark, quiet room. Both the float and non-float groups were measured with EEGs, and the study found that floating leads to an increase in the generation of theta waves. Biofeedback expert Thomas Budzynski concluded that float tanks increase the production of theta waves and believes that this has great potential for opening the mind to learning.