From: yaniv_vi_at_yahoo.com
Date: 2001-09-02 13:21:11
hi
is sound great , working with open eeg .
how do you feel ? how's alpha feedback feels ?
yaniv
--- 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
This archive was generated by hypermail 2.1.4 : 2002-07-27 12:28:32 BST