Memory

• YT: How Your Brain Chooses What to Remember

  Hippocampus handles episodic memory during waking hours, and in sleep repeats strong memory patterns to neocortex which then stores them for long time.

  • Hippocampus is part of brain taking part in episodic memory (memory of sequence of events).
  • Hippocampus has two modes (one when awake and when asleep).
  • Wakefullness Mode: When awake it tracks where and when things happens
  • Sleep Mode: When asleep it replays main events from the day. And stores them in neocortex.
    • Consider a part of hippocampus
      • A surge of "sharp wave" activation arrives there from higher part of hippocampus
      • It tries to wake up (excite) the neurons in that area
      • But there are inhibitor neurons that don't allow all neurons to fire at once
      • So, there is a competition. And the neurons that formed strong bond during the day fire.
    • This surge happens multiple times and in short intervals.
    • And the memory patterns that were strong get replayed and transferred to neocortex
  • During sleep, neocortex enters a state where it is receptive to signals from hippocampus
  • And when same memory patterns are repeatedly sent by the hippocampus to neocortex, it stores them in its permanent memory