 Hi, and welcome back to this video in the biological psychology video course in this video video 4.5 We're going to take a look at long-term memory Now what is long-term memory long-term memory is not really one thing, but it's more of an umbrella term For any type of memory that is more persistent than working memory, right? So in the previous videos, we've taken a look at sensory memory, which lasts maybe one second then working memory Which lasts for as long as you actively maintain and rehearse it, right? So you can keep a few items like digits from a phone number in your working memory for as long as you actively rehearse it And anything that is more persistent than that and that does not require active rehearsal is called long-term memory Now long-term memory has no clear capacity limit Maybe it's infinite. Maybe it's not So right, there's not I don't think there's any will be any moment any point in your life at which you're going to Find that now your work your long-term memory is full and you cannot form any more new memories. That doesn't really happen So in this in that sense long-term memory has is has an infinite capacity But of course you also forget things and there are imperfections in long-term memory So this essentially in a sense It is kind of pointless to talk about the exact capacity of long-term memory, but whatever it is it is very very large And long-term memory is often divided into different forms of long-term memory And so we're going to take a look at these different forms of long-term memory But keep in mind that they are convenient ways to talk about long-term memory But the the distinctions between them are fuzzy, right? There are often you can quite easily think of types of memory that are quite of kind of in between different categories But here we go So here on the right you see a figure from open stacks Where that's sort of depicts the standard way in which long-term memory is categorized So we have long-term memory and then we have explicit or declarative long-term memory And that is all the memory that you have conscious Introspection of right so the in a sense. It's the memory that you know you have right so for example I know that the capital of France is Paris. I know I know that right? It is something that I have conscious introspection in And then we have non declarative or implicit working memory Those are the forms of memories that you don't have conscious introspection in for example I Can ride a bike and I can get onto a bike and I can ride it But I don't really have any conscious introspection into how exactly I do that right? It is sort of something that my body does Without I know that I can do it so the fact that I can ride a bike is a form of declarative work Long-term memory, but exactly the details of how I am riding a bike and how I keep my balance etc That is that is definitely Implicit long-term memory because I have no insight exactly into how I am able to do that. I just am Now if we focus on declarative memory, we can further distinguish semantic memory Which are memories for facts for example again Paris is the capital of France. It's a fact right for now And we contrast that with episodic memory which are memories for things that happen to us or more generally sort of memories That have a time and a place memories for events, right? So for example, I met a beautiful girl in Paris would be a an episodic memory It has to do with me it has to do with a particular place and a time, right? It is an event So semantic memory and episodic memory are different forms of memory generally speaking But as I said, of course, you can think of intermediate intermediate forms between them And I think that happens for example if you say that you have some kind of story that you're telling over and over again right for example when I move to Groningen to Then people ask me all the time like okay, are you new in Groningen, blah, blah, blah I read I say this tell the same story over and over again and at some point I think the episodic memory of of me moving to Groningen has become a dry fact something something that I just have in my Semantic memory, right? I've told it so many times sort of lost its personal the memory sort of lost its personal component Right, so you get things can I think transfer from episodic memory into semantic memory quite easily especially if you if you Talk about it a lot Now within the non declarative memory we can distinguish for example procedural memory, which is the memory for skills For example piano playing or riding a bike, right? So those are skills that you can do or you cannot do them, but if you can do them you do that Implicitly right you it is just something that you have trained and at some point you're able to do it You have no introspection into exactly how you are able to do it Which also makes it very tricky to teach it to other people, right? And that is procedural memory motor memory And then there's also conditioning and conditioning is basically associating things with each other For example Pavlov's dogs, right? Pavlov is a famous psychologist Was a famous psychologist and he trained dogs He paired food with a bell and then he did that so often that at some point the dog started to really very strongly Associate the bell sound and food with each other and then just hearing the bell by itself would already make the dogs Salivate drool because they they were anticipating food right now Conditioning is very often linked to emotions. So They're not necessarily but in most cases. I think think it is and for example I think one one form of conditioning that many people experience is the conditioning between smell and Romantic feelings, right? So if you if you've been in love with someone and that someone in that person wore a particular kind of perfume or smelled in a particular way Then you start associating those dough that smell with the feeling with the romantic feeling and that can that kind of That is a form of conditioning that can persist for a very very long time, right? Even long long after you've broken up or you've moved that that sort of that Smelling that particular smell can trigger those same kinds of emotional memories quite easily, right? Illustrating also the strong link between memory and emotion Now so how is long-term memory represented in the brain? We don't know no one knows One possibility and probably true to some extent because it's such a generic statement is that the entire brain is possibly involved in long-term memory Now just saying that the entire brain does long-term memories, of course, not very helpful. So can we be a little bit more specific? Well, we know that some brain areas are a little bit more involved in some forms of long-term memory So for example, we have the hippocampus, which is located here in the temporal lobe And the hippocampus is involved in encoding and retrieving of memory So if you have damage to the hippocampus that will give you kind of amnesic problems There's the amygdala also located very near the hippocampus And the amygdala is involved mostly in the emotional aspects of memory sort of linking memories I would say to emotions and because Emotions are so in such an important aspect of of memory We will talk about emotions in more detail in the next section But because emotions are so important in memory the amygdala this emotional brain area is also very important in memory We have the cerebellum, which is this little Little cabbage-like structure in the back of the brain, which is very strongly involved in procedural memory So learning motor skills So those are the brain areas to keep in mind the hippocampus I would say is is generally speaking the first brain area that people think of when they think about memory But the amygdala is also important for emotion and the cerebellum for motor skills for implicit procedural memory Now with that let's move on to the next video in which we're going to talk about to me a very fascinating subject The reliability of memory