[FieldTrip] Eyes-open EEG stimulation via the ear canals
Gregory.Perry at govirtual.tv
Wed Oct 10 15:42:34 CEST 2012
I am not aware of any photoreceptors in the ear canal, and I am not quite sure exactly why this method works the way it does. Different wavelengths at varying intensities focused into the ear canal evoke different brainwave responses, and the effects are quite dramatic - insert a light source into the ear and an immediate response is seen on the EEG FFT analysis and charting output, remove the pulsing light source and it immediately does away.
I do not currently have access to an fMRI setup so I cannot say with any level of accuracy which major cortexes are directly implicated beyond associating the 10/20 region/scalp electrode that is reporting back strong FFT activity. The light sources are optically coupled with light pipes so I believe electromagnetic interference with the scalp electrodes can be safely ruled out. The light pipes are insulated with 1mm black jackets and with only about 2mm of light pipe exposed inside the ear canal, so I think that side channel light from the ear receptacles themselves can be safely ruled out as influencing the EEG charting via the visual cortex as well.
So far my best guestimate is that light projected through the inner ear is close enough to the brain to permeate through any obstructing tissue, depending on the intensity and wavelength of light being used. Green and blue seem to be the dominant wavelengths in terms of the measured EEG responses I've observed so far.
More testing is needed from a diverse user base, hence the Indiegogo crowdsourced funding project to develop an open source experimentation platform for widespread community participation in testing of this method of brainwave stimulation.
I will be posting more detailed screencasts illustrating the EEG FFT results in the upcoming days; the strongest responses so far are in the delta band which is strange as well.
----- Original Message -----
From: Eelke Spaak [mailto:eelke.spaak at donders.ru.nl]
Sent: Wednesday, October 10, 2012 03:01 AM
To: FieldTrip discussion list <fieldtrip at science.ru.nl>
Subject: Re: [FieldTrip] Eyes-open EEG stimulation via the ear canals
Thank you for this mightily interesting invention, which has the
potential to revolutionize EEG research. However, I am still a bit
puzzled as to the mechanism of action. By what route do you imagine
the stimulators would entrain brain activity? Any references
describing photoreceptors in the ear canal would be very helpful.
All the best,
On 10 October 2012 01:00, Gregory Perry <Gregory.Perry at govirtual.tv> wrote:
> Something of interest for the list members; I've been working on this photic
> stimulation system for about a year now, to facilitate EEG-research and
> experimentation using an alternative to conventional visual cortex-based
> photic stimulation systems. This method involves only the ear canal:
> fieldtrip mailing list
> fieldtrip at donders.ru.nl
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