This lecture is on memory, and we're continuing the journey now started in the previous lecture. Going from the world, from our perception of the world, to attention, and now, through memory. So you've seen something, you've attended to it, and now it gets into your head. Memory is complicated. When you imagine somebody losing their memory, you might think of Jason Bourne traveling through Europe, having adventures but not knowing about his past. You don't think of somebody in diapers lying on the floor, unable to move. Yet, memory underlies everything we know, not just our autobiography. So, when we imagine somebody losing their memory, we often imagine just autobiographical memory, memory of the self. But of course, this is just one part of what memory is. Now, there are certain distinctions we should keep in mind when we talk about memory. One is the distinction between implicit memory and explicit memory. Explicit memory is what you consciously know; you know your name, you know the capital of Canada, you know what you had for breakfast this morning. While implicit memory is stuff that you may not be conscious of. You might, for instance, forget that you've ever been to a place, but at some level, know your way around. There may be a word that is unfamiliar to you consciously, but at gut level, you know what it means. There is a distinction between semantic memory and episodic memory. Semantic memory are facts. Again, the capital of Canada. While episodic memory is about episodes of your life. When we talk about memory, we talk about encoding, storage, and retrieval. Encoding is what happens to get information into your head, storage is keeping it in your head, and retrieval is getting out of your head. We talk about recall versus recognition. These are two different ways to tap memory. Recall is freely recounting what you've experienced. So, if I asked you what I was wearing during my last lecture, if you were to answer, that would be recall. While recognition is from a set of options, which one is it. So if I was to show you five pictures of what I was wearing last lecture, which is kind of a strange example because I'm an avatar. But nonetheless, if you picked the right outfit, you'd be succeeding at recognition. If you want to think of it this way, recall is more a short answer exam or an essay exam while recognition is more multiple choice. Finally, there is the distinction between sensory memory, short term memory and long term memory.