[MUSIC] Okay, so let's talk about the two different types of declarative memory. One is semantic and one is episodic. And semantic memory is facts. Things like George Washington was the first president of the United States, or the word, multiple, means more than one. Those are facts, those are semantic memories. And they are in a different category than episodic memories, which are memories of events, things that happened. Autobiographical memories are episodic memories. So, let's just understand how this works. When my niece was about six years old, we had a big family party and everyone was all excited, and there was a lot of hubbub. And everyone was gathered and my brother said to, to his daughter, okay, whatever you do, daddy worked really hard to grow this pepper. Don't pick the pepper. What did my niece do? She immediately, of course, picked the pepper. So this story has been told and retold to her, and to the family. It is a family-favorite story of my niece being naughty, and everyone getting a big kick out of it. And so, in fact, that episode started as an episodic memory. Everyone remembers it actually happening. But because it is retold and retold, it has morphed into a semantic memory. And how can we tell? Because if I asked my niece, what were you wearing when your father told you not to pick the pepper? Pretty sure she'd have no clue. What was your dad wearing? Was it sunny or cloudy? Was there a wind? Could you smell the blossoms of any particular flower? She would have no ability to transport herself back into that episode and explore the memory. It was no, it's no longer an episode. It is turned into a semantic memory, so she's remembering not so much the memory, or the incident, she's remembering the retelling. And a great deal of our episodic memory starts out as episodic memory and becomes a memory of the, of the retelling of the memory. So, in the next segment we're going to ex, further explore the rich detail of episodic memories. [MUSIC]