Loading ...
Sorry, an error occurred while loading the content.

1178Re: Alpha/Theta feedback

Expand Messages
  • yaniv_vi@yahoo.com
    Sep 2, 2001
      is sound great , working with open eeg .
      how do you feel ? how's alpha feedback feels ?

      --- In buildcheapeeg@y..., "Joerg Hansmann" <info@j...> 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
      > the volume and everything above 50uV is played at maximum volume.
      > With this setup I have been able to increase Alpha (lying position,
      > closed), so that the Alpha-feedback sound is played nearly 100% of
      > 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
    • Show all 13 messages in this topic