yana-notes

Theta waves

10-31-2021: Neural Oscillations

Theta waves #

  • (4 - 8 Hz)
  • Creativity, hypnagogia, deep relaxation/meditation, visualization. The predominant cortical frequency during REM in both humans and rats.

Should be no mystery to me it’s implicated in hippocamal processes. I think it has a role in slowing things down to keep many things in working memory at once. Temporal (and sometimes frontal) theta is a bit of a biomarker of hippocampal activity.

  • The more time somebody spends on-task, theta rises to match any increased fatigue.

    • However, theta also increases during deep, relaxing Meditation - but it’s apparently mostly in left frontal/central sites. R Thus, whole-brain theta would be a better marker.
  • Theta synchronization can either be characterized by a narrow-frequency power increase - or irregular slow activity AKA large irregular activity, which is a tonic increase at large during Sleep, etc., which is quite distinct from phasic narrow band synchronization that characterizes memory encoding/recall (or during REM, recoding). ISA/LIA probably inhibits memory, which clearly explains why you don’t remember much during sleep.