Sound and light

[nmdanr2b]

For neurofeedback training, future evoked potentials studies, and detecting neurostimulation effects visual/audio output is highly useful. It can also be useful as output for basic influence traditional sound-and-light machines style.

Such output is highly representative, will be great for the science museum exhibition, and in particular if more than one output type is triggered by an event can be used for synesthesia training (for example, via association of light/colour/picture (visual) with sound (audio) and EEG activity (see triggers in "EEG processing and triggers for action"). We can even associate it with a neurostimulation signal at the same time in a selected 10/20 position!

1. Light a) I suggest using 3 LEDs, lets say blue, green and red b) options: do not use LEDs, use all LEDs (below the selected threshold (see "EEG processing and triggers for action") - blue, above - red, in between - green), use the selected LED only (above - on, below - off), use two LEDs (e.g. below the threshold - green, above - red) c) optionally, a frequency of a selected brainwave band as measured in real time can be fed to a selected LED to make it flash. d) LEDs can also be fed from the device frequency generator e) for c) and d) it is optimal to mount the LEDs close to users eyes light-and-sound machines-style
2. Sound. a) associate each brainwave band with a preselected, preloaded soundtrack which is played when a set threshold for this band is exceeded b) if the band power goes below the threshold it stops playing c) otherwise wait for another band to go over the threshold and switch to the corresponding soundtrack d) for the case c) allow a custom pre-set time (for example, 10 seconds) before the switch so that there is no constant switch-over between the soundtracks e) as the normal brainwave spectrum is 1/f, there could be predominance of lower frequency bands and the corresponding soundtracks, although tweaking the thresholds should solve this problem. However, to further address it I propose to give priority to higher frequency bands in case of a tie. f) as an optional possibility soundtrack volume can be correlated to its corresponding band power. In such a case there could be an option of playing a soundtrack for a selected band without a threshold, with regulation of its volume used for neurofeedback

This effectively turns the device into an EEG-controlled music box with associated LEDs lighting up or flashing. For the latter, see c) in 1. Light above.

Note that instead of music soundtracks anything else (saved brainwave data etc) can be replayed through whatever is connected to the sound jack.

[nmdanr2b]

My associations of brainwave bands with music are as follows:

• alpha - slow noise/industrial, lullabies (for fun)
• theta - jazz/funk (orientation)
• alpha - chill out, meditation chants
• low beta - rock/pop
• high beta - speed/power metal
• gamma - fast techno/trance/goa

But may be we want to use classical music recognizable by everyone only.

Lets discuss the associations everyone has.

P.S.: we can have more than one soundtrack associated with a specific band anyway

[nmdanr2b]

if there is any kind of a connected display, then a picture associated with a brainwave band can also be presented. This is great for neurofeedback, sinesthesia etc.

[nmdanr2b]

I wonder whether it makes any sense to induce phosphenes when tACS is eventually implemented as an action to a trigger :)