From: yaniv_vi_at_yahoo.com
Date: 2001-09-05 14:03:14
hey peterson
i have a question :
what jeoirg described in his experience of 5 days of alpha
(alpha/theta) nfb , is decresead sense of self and feeling of
emptiness .
this ar supposed to be very high realizations in buddhist
meditations ,really really high!
is this common for such a short time in other ppl also ?
sincerly yaniv v
--- In buildcheapeeg_at_yahoogroups.com, peterson_at_d... wrote:
> Joerg--Glad to hear you are playing with alpha-theta. Yes. A2
> (actually Au2) would be the right earlobe. If your other electrode
> is at Cz I imagine you could use your left earlobe (Au1) instead if
> you wanted to, with no particular difference in effect.
>
> Many people--I suppose most--are able to produce stronger alpha
than
> theta. You should set the theta threshold separately, not use the
> same one as for alpha. You will need to experiment to get the
right
> threshold, but it should be one that provides feedback about 25% of
> the time for theta. Also as you get better at producing either
alpha
> or theta, you can set the threshold for that band up higher. If
> you're exceeding an alpha threshold of 25 uV 90% of the time, set
it
> up a few microvolts til you're only exceeding threshold 50 or 60%
of
> the time.
>
> Also, traditionally, alpha-theta is usually trained at O1, which is
> on the back of the head. Both the Greens and Peniston use(d) this
> site. Find a bony bump at the back of your head about 3 or 4 cm
from
> the top of your neck. This bump is called the inion, and is a
> beginning-point for locating EEG sites. O1 will be about 2.5 cm up
> and 2.5 cm to the left of that bony protrusion.
>
> Actually, though, since you started training at Cz, there is
probably
> no reason to change now. At least one published alpha-theta study
> used (if I remember correctly) C3 and got perfectly good results,
so
> probably anywhere from Cz back is OK.
>
> If you just want to train alpha, Pz is probably the best site, but
> again Cz would be OK. Since you apparently aren't getting much
> feedback on theta, you are probably actually doing alpha training
in
> effect.
>
> --- In buildcheapeeg_at_yahoogroups.com, "Joerg Hansmann" <info_at_jhansmann.de> wrote:
> > Hi,
> >
> > since about 5 days I am using the comEEG prototype for
> > Alpha/Theta audio-feedback. Electrode positions for
> > 1 channel are Cz - A2
> > (A2 should be right ear lobe. Is that right ? My picture with
> electrode-
> > positions is a little bit unclear).
> >
> > Audio-feedback is given using two sine-wave oscillators (one
lower
> > frequency for Theta and one higher frequency to indicate Alpha)
> > which amplitudes are controlled by the geometric addition
> > (root sum of squares) of the FFT output for each frequency band.
> >
> > If a (fixed) threshold of 25uV is met, the feedback sound
> > is played at a low volume. A voltage between 25uV and 50uV
increases
> > the volume and everything above 50uV is played at maximum volume.
> >
> > With this setup I have been able to increase Alpha (lying
position,
> eyes
> > closed), so that the Alpha-feedback sound is played nearly 100%
of
> time.
> >
> > However I have no idea how to get significant Theta.
> >
> > What am I doing wrong ?
> > Should I train Alpha with higher thresholds first ?
> >
> > And what is the great difference in
> > inner perception between Alpha and Theta ?
> >
> >
> > Regards,
> >
> > Joerg
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