I see a lot of questions regarding the significance of mind machine features. Here I will address the main points.
In the interest of not creating a mire of detail I will break the field down into four categories. Some devices fall into more than one category and some include features that are not found with any other, such as CES (cranial electro stimulation) on the David Pal CES or GSR biofeedback control with the Proteus in conjunction with a Thoughtstream, also from MindPlace.
AudioStrobe is the de facto standard for 2-channel light control encoded audio. The channels are traditionally assigned to red/green or left/right.
To enjoy these visuals an AudioStrobe decoder, an audio source (i.e. PC or MP3 player) and suitably encoded content are required.
An example of a pure AudioStrobe device is the MicroBeatMini. Of itself it can do nothing. In conjunction with an encoded audio source it delivers superb 2-channel visuals. The two AudioStrobe channels can be mapped to any variation red, green, white and left/right.
Devices that I have reviewed that have AudioStrobe in addition to other features include the Procyon, Proteus, Sirius and InnerPulse.
As for content – there is a huge range of material out there and most manufacturers include generous samples. For those who wish to create their own material, Transparent’s Neuroprogrammer is an excellent starting point, including, as it does, so many sample sessions, meeting all recognised needs, that there may end up no need to do anything more than tweak to your taste. AudioStrobe Designer, from TC-SoftWorks is the definitive tool for encoding existing audio, although there are other means and tools to achieve this end.
Other audio control formats include TurboSonix (iLightz), which is so close to AudioStrobe that AS encoded content works quite well and MultiSensori, which is a 6-channel light system, allowing left/right control of red, green and blue LEDs. I have not reviewed a MultiSensori device.
These devices have independent, standalone sound generation and light control. Being free from the limitations of encoded audio, the native sessions included with these units can be truly spectacular.
Such devices generally include, or offer optionally, PC based session editor software that facilitates the creation of device-specific session files.
The sophistication of the synthesisers, light controllers and associated editors vary enormously. For example, the Procyon has awesome light and good audio control, while the Proteus has awesome audio and good light control (the former being three and the latter two colour). None of the session editors I’ve used could be called friendly, but if you know what you want to achieve the learning curve is far from insurmountable.
The native sessions included with these devices cover the common range of purposes, from deep sleep/meditation to full-buzz alertness and everything in between.
Nothing other than device specific files can be uploaded to a pure synthesiser device (no MP3 or suchlike).
All of the devices in this category that I am aware of have an audio-in or auxiliary socket through which to play audio from an external source alongside the integral session. Most include AS decoding (of those I’ve reviewed only the David PAL lacks a decoder).
These devices include an MP3 player (some support WAV and/or OGG as well). Ordinary audio can be uploaded and played just as with any MP3 player. As with synthesisers, these machines also include a means by which audio and visual stimulus can be controlled, either by secondary control files or by encoded audio.
The Laxman is the obvious example.
At this stage I have used only one dedicated AVS device that falls entirely under this category – the MindLights. I have used a number of other non-AVS specific USB audio devices.
These devices must be connected to a computer where they appear as a standard or multi-channel audio device (think surround technology – 5.1, 7.1 etc.).
With the immense computing capability of a PC, as opposed to that which can be conveniently packaged in a standalone synthesiser, the range of effects and complexity of session is stunning.
USB audio is not without its problems, most of which can be avoided by diligently following the instructions, which include always using a main box USB port (no external hubs) and installing the device driver before plugging in the device.
Apart from these AVS source considerations there is also the matter of open- versus closed-eye. Personal choice. Open-eye with devices such as the Laxman or MindLights is awesome. Closed-eye with the Procyon is also awesome. In terms of raw effectiveness I consider open-eye optimal for high alpha and above while closed-eye is ideal for anything below mid alpha (the useful transition being around 10Hz – blink response frequency). Open-eye devices can be used eye-closed. Closed-eye devices cannot be used open-eye without hack modification.
Colours – which and how many. Again, personal choice. A single colour will provide all the stimulation required for directly brain rhythm related purposes. Bicolour and full colour (RGB) expand the breadth of visual experience and open the way for colour specific techniques such as overlaying two beat frequencies by utilising the distinct visual pathways used in seeing red and blue. Some manufacturers offer a range of different eyewear to provide additional colours and combinations. Personally, I like either white which delivers surprisingly wild multicolor visuals or full colour which is the no-compromise option with all colours including white accessible. There are colour systems that I have not tried, such as ColorTrak.
Portability and suitability for use in public. And again, personal choice. If you’re happy sitting on the bus with a laptop and a full face visor, then you’ll enjoy the MindLights. The Laxman is the current benchmark for AVS enjoyment in the wild – all you need in a single package and not excessively goofy eyewear. The synthesiser devices are all well suited to mobile use, with only the iLightz standing out as one you’ll probably want to leave at home due to its ungainly iPod dock design. A very tidy combination is the MicroBeatMini and your iPod or other MP3 player.
There is so much and so little to distinguish AVS devices.
Every one, without exception and according to its limitations, will deliver completely functional audio/visual stimulus. The whole point of AVS is to deliver sound and/or light pulses for the purpose of influencing brain rhythms.
Beyond that, each has distinguishing features that may define its usefulness or otherwise for any particular application or environment.
My favourite devices are the Procyon, MicroBeatMini, Laxman and MindLights, representing all the major distinctions.
Of course, things change and new devices appear on the market. Apart from a few oddball devices, such as the Lucia (which I have not met personally) I will be very surprised if any surface with features substantially beyond or different to those covered here – it will just be a matter of how a feature mix is packaged.
And finally, be aware that there are no secrets to AV stimulation – any claim that a device is substantially more effective than any other is likely hyperbole. Always remember “flash and beep” – that is the basis and all else is frippery. The frippery, however, is the part that must appeal to you to make the use of the device compelling – you’ve got to use to benefit from it! Don’t worry that you might buy a device that doesn’t work – concern yourself with choosing a machine with the additional features that appeal to you. And don’t be too surprised if you end up with more than one device.