XPost: alt.dreams.castaneda, alt.dreams, alt.magick   
   From: askpermission@comcast.net   
      
   "kever"  wrote in message   
   news:%PY6g.409562$GJ1.11211814@phobos.telenet-ops.be...   
   > :-) nice one tom , but what i meant was the times intervals between the   
   > first and second , after how many time starts first sleep and second   
      
   Heh.  I calls 'em as I sees 'em.   
      
   Usually these days we industrialized sorts don't experience first and second   
   sleep.  We tend to go to bed too late because our electric lights allow us   
   to function effectively so long after sunset and then we sleep right through   
   the night.   
      
   However, by looking at the sleep stages we can identify by research, we can   
   probably figure out just when these ancient categories of "first sleep" and   
   "second sleep" arise.   
      
   Sleep researchers who monitor brain activity with an EEG identify five   
   stages.  Stage one begins with the onset of long, slow theta waves.  In   
   stage two, these theta waves continue but are interspersed with "sleep   
   spindles", sharp spikes in activity with last only a short time.  If we are   
   awakened during either of these two stages, we would report not feeling like   
   we were asleep at all.   
      
   Stages three and four are characterized by delta waves, which are even   
   longer and slower than theta waves.  This is our deepest sleep.  Stage five   
   is REM sleep, during which dreaming takes place.  If not allowed REM sleep,   
   we don't feel properly rested in the morning and our performance shows it.   
      
   After that, we go back to stage one and start the whole cycle over.  A cycle   
   tends to last about 90 minutes.   
      
   So we can estimate that the wakefulness interval between first and second   
   sleep probably begins on some multiple of 90 minutes.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)