Brainwaves and electroencephalography (EEG) - entrainment

My first attempt to entrain myself was rather successfull. I mixed entrainment sounds together with nature music (sea waves). The CD-quality music was modulated with low sine frequencies, the amplitude of the entrainment tones was 10 times greater then those of the music. This entrainment frequencies were applied: left channel 5Hz, right channel 15Hz, therefore the differential frequency was 10Hz. The minimum frequency was chosen for my headphones (SONY MDR-V600), they can carry signals from 5Hz. I also mixed first the CD music sound tracks, so that both channels were identical.
I felt the difference (between original and modulated sounds) immediately during the first hearing (I am rather sensitive and responsive to music as it was always a hobby). Although I did not hear the low tones, the impression was that the music is simply more pleasant (I compared with and without entrainment tones). My total hearing session took not more then 5 minutes, because I had to go to bed, it was too late. When I was in bed, I started observing the results. I felt they were significant. I was very calm. I should explain here, that for me it happens quite often, when my brain activity increases during evening. And it happens very often that when I go to bed, I become very excited for example because of various ideas (this experiment was a result of such an idea performed yet the same evening :-)), so sometimes I can't sleep because of that. This time it was different. I did not become excited at all even if the results of the entrainment seemed to be working and normally that would make me anxious. Instead I was calm and contemplating my current state of mind and body. It was nice. It was similar to like after meditation state, but more thorough (I am not a meditation expert though). It was great until I wanted to sleep. It turned out then that my alpha state did not want to go away (to sleep I needed theta). After considerably longer then usual time and after extensive relaxation I was able to fall into deep sleep. I woke rather early and was restful. What was interesting, the alpha state remained. I was calm and happy just the same as during the last evening. I went to work. While driving the car I made first unpleasant observation. My reaction to the external events has slowed down. Because of lower attention, I was once close to bump a car ahead of me, then I entered cross section on red lights, generally I noticed that my realization time (of what is happening) has increased (comparing to my normal state). Nothing serious happened and I remained calm till about noon.

The conslusions:
  • we should be cautious with any entrainment experiments. They may have unexpected effects.
  • entrainment results can remain for longer time then expected.
  • in the above case I performed the entrainment in relatively short time, it was more then enough
  • it may not be possible to measure enrainment results with eeg because because of the response time.
  • I figured that it will be more efficient to use natural music rather then a set of various artifically generated tones. Simply because mind is much more open towards something it likes. In the past I did try BWGen software, and I did not notice a significant effect on me. I think it could be the best to mix one's favorite (but relaxing) music with entrainment tones.
  • the entrainment tone's amplitude must be relatively high. If it is just another "instrument" to the song, it would be lost among others tones and be less effective in short term (maybe better in longer term).
  • I was aware, that the above results could have been significantly influenced by my auto-suggestion.
  • I did the above experiment after several meditation attempts (I tried to measure eeg alpha with modularEEG). It could be related, because the entrainment results in this case were the same as goals of the earlier meditation.