- Mind Machines
The phrase "mind machines" covers a whole range of technologies that may work directly or indirectly on your mind or consciousness - e.g. binaural beat and multi-source hypnosis, light and sound mind machines, electrical stimulation devices (TENS, CES), biofeedback, radionics, sensory deprivation tanks.
- Binaural beat
Binaural beat works by playing two frequencies, one into each ear.If one is playing 240 Hz and another 230 Hz, the difference between two frequencies - 10 Hz - is referred to as binaural beat frequency.The binaural beat produces a sensation of a "third" sound. Specific combinations of frequencies facilitate experiences of different states of mind from profound relaxation and laser-like concentration, to expanded states of consciousness.
- Multi-source hypnosis
Multi-source hypnosis works by playing two different hypnosis scripts, one into each ear.Listening to these recordings,you'll find that you can pay conscious attention only to one script, while the other one is by-passing your conscious awareness and going straight to your subconscious. This works somewhat like a subliminal recording, except that you can hear the messages if you choose to pay attention to them.
- Light and Sound Mind Machines
Light and Sound (L&S) machines combine pulsed tones or binaural beats with light stimulation (flashing lights in your eyes).
- Electrical Stimulation Devices
TENS stands for "transcutaneous electro-neural stimulation," or running electricity through the nerves in your skin.TENS devices are used forcontrolling chronic pain.
CES stands for "cranial electrical (or electronic) stimulation," or running electricity through your head. In some cases, the frequencies are quite low, using small A/C pulses at brainwave frequencies. In other cases, high frequencies or white-noise random signal generators are used. - Biofeedback
Biofeedback devices make it possible for the users to see or hear some bodily process that was hard to monitor before, so that they can try to control it.Some devices report back skin temperature, galvanic skin response (GSR), muscle tension via electromyelogram (EMG), and brainwave frequencies via electroencephelogram (EEG).
- Radionics
Biocircuits, radionics, subtle energy, chi generators, orgone, and psionics are all so-called "technologies" for manipulating the body's energy fields.
- Sensory Deprivation
Ganzfeld goggles are the least invasive sensory deprivation devices. The idea is to fill your entire visual field with an even, featureless, monochromatic light.
Flotation tanks or sensory deprivation tanks are on the other end of the scale in complexity and expense. The user lies in a light-proof, sound-proof tank filled with 10" or more of 92° Farenheit water into which hundreds of pounds of Epsom salts have been poured so that they float effortlessly, and stays there with no sensory input other than their own breathing for four hours or so.
Dry floating is an attempt to replicate some of the effects of a floatation tank with a modified waterbed mattress instead. - Nootropics
Nootropics (smart nutrients and drugs) are used to improve mental functions.Some nootropics also claim to rejuvenate the body. A good resource for information on nootropics is Cognitive Enhancement Research Institute.