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Okay. |
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Good morning, everybody. |
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I think we're on the mic. |
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Yeah. |
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Welcome back. |
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Unfortunately, last week we had a strike. |
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Action affected you. |
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Today, there's no strike. |
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So please be quiet for the start of the lecture. |
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So today, this week, returning from last week, all motivation |
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and consciousness to memory. |
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We're today going to focus on human memory, a particular |
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condition that illuminates a lot of our memory. |
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And on Friday, we'll pick up on animal research. |
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This holiday on tonight. |
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What do we know about what the cells are doing? |
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So in this lecture, you should know about different types |
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of amnesia. |
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This is the topic of today, the brain regions involved. |
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Examples of the neuropsychological tests which would be important if |
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any of you are interested in going on into clinical |
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psychology and the functions lost or retained in amnesia and |
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controversies. |
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So what is happening here? |
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Amnesia is defined as a profound loss of memory in |
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the in the in the presence of relatively preserved cognitive |
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abilities. |
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That's a bit of a mouthful. |
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So what it implies is not some of these just |
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lost memory. |
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So we're interested in people who have lost memory and |
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profoundly not forgot where the book is or where they |
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park their car or something like that. |
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Someone who just can't remember any experience of having. |
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And also they can do other things that have normal |
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function. |
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So if you say somewhere else, Alzheimer's and amnesic patients, |
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the answer is no. |
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And we'll see you in a moment. |
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So why is it interesting? |
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As you'll see in and as you've seen from lots |
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of lectures in this course, when the system breaks down, |
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this case amnesia goes that we can learn a lot |
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about how the system normally functions. |
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How does healthy memory work when we do have our |
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memory? |
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And if you take an example from culture about memory |
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is a quote from Michael Crichton, who wrote Jurassic Park, |
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and this is his book, Sphere At the end of |
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the entire narrative of the book around memories, as though |
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the characters in the sense the character thought, all we |
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consist of is memories. |
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That's who you are in the audience and the way |
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our personalities are constructed from memories. |
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Our lives are organised around memories. |
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You came here today because you had a lecture. |
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Our culture is built upon memories. |
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The foundation of shared memories is what we call history |
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and science. |
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So this is kind of an attempt to capture the |
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profound nature of having memory and how devastating we didn't |
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need it to survive. |
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What to eat? |
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Where are you supposed to be? |
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What you're what to avoid? |
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All these things that allow us to survive. |
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What I'm going to talk about today is despite having |
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a lack of memory amnesia, patients will say, you can |
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do an amazing range of things. |
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So here's a YouTube link to something. |
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I'll show you an example. |
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It starts with the man with amnesia playing a piano |
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and remarkably well. |
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Hopefully the audio work for this. |
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One man is consigned to live entirely within the. |
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Present with terrible consequences. |
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Clive Waring has the worst case of amnesia. |
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He lost his memory. |
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And now his wife, Deborah, is the only person he |
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recognises. |
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Oh, ho ho, ho, ho! |
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It really only has less than 30 seconds memory, and |
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sometimes it's as little as perhaps 7 seconds. |
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It's as little as a sentence. |
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I'm going to see your sister down at dances. |
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Got married recently in New Zealand and said they're having |
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a party from her. |
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The Ladies Club title. |
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A married man will see to know how much he |
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knows how many guests he didn't put down. |
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I need to know why I'm going. |
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She's having a party at her house tomorrow. |
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She will say no. |
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I know it is to do with her daughter. |
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Do you mind have daughters having a party? |
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Yes. |
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No. |
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She's just got married. |
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She just got married. |
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And did what country? |
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She just got married in New Zealand. |
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Oh. |
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Yeah. |
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The sentence he is in. |
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He will probably have forgotten the sentence before you ask |
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him a question, and he'll give you an answer. |
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But while he's giving me the answer. |
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He's already forgotten the question. |
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But so bad it is and is worth watching to |
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the end of it. |
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I'm not going to court that because it highlights just |
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that case of Clive wearing just tie for normally tense |
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and these you can be trying to trying to imagine |
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how crippling that would be if as I'm talking to |
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you now, you forgotten why I started the sentence. |
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What was I talking about? |
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This is the classic description from Dani's ex, like Clive |
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Waring, is that it's like waking from a tree. |
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You know, you woken up in the morning, you're a |
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bit dazed, and you've been having a really intense dream |
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about something and it just fades. |
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And someone says, What were you thinking about in your |
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dream? |
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It is really intense for you, but it just evaporates |
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and you can't remember that. |
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And they say, certainly Clive says this in the video. |
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That's like it all the time for him. |
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And he's really angry because he knows he should know |
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things, but he can't. |
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And he says the doctors have been useless, unable to |
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help. |
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He's just absolutely straight. |
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So it's quite it's a quite a side effect of |
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amnesia. |
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But let's not forget what he did at the beginning. |
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He's got no memory. |
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But how did he remember to play the piano with |
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absolute expert precision? |
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So he does have some memory. |
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And what is the memory he has now as we're |
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starting this lecture is that's the interesting bit about Clive |
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and his wife, Deborah. |
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And also she dies every time he meets his wife, |
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Deborah, that you saw when he opened the door, He |
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jumps up and kisses her and cuddles her every single |
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time. |
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So she goes to make a cup of tea and |
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comes back. |
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He's felt like he's not seen her for years. |
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And so it's extremely difficult for his wife as well |
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as her. |
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So just to highlight the challenges. |
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So Clive, in that narrative has what's known as organic |
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amnesia. |
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There's a there's a he has brain damage that has |
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caused his amnesia. |
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There are fascinating. |
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The psychogenic amnesia is caused by causes where patients suffer |
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mental health problems and cannot remember things. |
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We're not going to touch on that today, but they |
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are they are fascinating and much more complicated. |
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And I'm talking about the transient amnesia is so epileptic |
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amnesia is, for example, a schema accompanies. |
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Is that cause a complete loss that people wake up |
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from this condition unable to remember what they're doing in |
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the hospital, where they are, why they're there, what's going |
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on? |
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They're amnesic like lies. |
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But within a couple of days or weeks, it returns |
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to normal, comes back. |
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They don't have persistent amnesia. |
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Clive has this organic, persistent. |
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He's never remembered anything since his brain damage. |
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And the other thing Clive has is this non degenerative |
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form. |
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He isn't changing. |
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He's just got the same memory problems day in, day |
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out. |
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Degenerative amnesia has come under Alzheimer's disease and other conditions |
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that keep getting worse. |
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And sometimes you have this new terrible specific you can |
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have brain surgery and end up losing memory for words |
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then on other things or in the case of Clive. |
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And what we'll be talking about today is the classic |
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Amnesic syndrome. |
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Where is all material? |
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There's another audio, verbal, written, any information coming to him |
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that he's trying to recall? |
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It's it's lost. |
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So let's dive now from the what is amnesia to |
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what was causing that. |
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This is a brain in behaviour. |
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So it's about the behaviour that's going to the brain. |
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Well, the first place to start with that is the |
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most commonly damaged brain area for amnesia is the structure |
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of the hippocampus. |
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Now he focuses a picture through a schematic of the |
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human brain and one of the images from the tutorial |
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you get on anatomy. |
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And we talked about the hippocampus in regards to the |
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impact of stressors and how that stress disrupts memory. |
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And today we're going to talk about it a bit |
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about the hippocampus beyond stress in terms of other factors |
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that can damage it. |
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And on Friday, we'll come back to the two things |
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that sort of tests that can be used in animals |
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we thought about in more detail. |
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But here's the hippocampus gets his name because it looks |
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a little bit like a seahorse. |
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You can see that stylised in the brain of a |
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human post-mortem brain. |
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Here it is curled up in the medium term for |
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lobe. |
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So where is the hippocampus is in the temporal lobe |
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and it's in the medial powers. |
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If we take a coronial section is the temporal lobe, |
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and here is this folded up structure of the hippocampus. |
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Here, let me slice through a horizontal or a horizontal |
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section. |
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We can see the hippocampus is tucked away here. |
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There's one hippocampus in each hemisphere, and it's huge in |
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most mammals in the sense. |
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Takes up a lot of the brain. |
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And interestingly, it looks very, very similar. |
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Here's your hippocampus. |
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Here's what you have to have. |
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This would look like a version of your brain. |
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So the cadaver is level surgically. |
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You don't want to happen, of course. |
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But if you had to do that with a bat |
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or a sheep or a giraffe, it would look almost |
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identical to yours. |
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So the evolution is tinkered with these things, but hasn't |
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really changed the hippocampus. |
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It's doing something utterly important for giraffes, bats and humans |
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and whales. |
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All of them have a very similar looking hippocampus. |
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There's this stuff around in the neocortex that has radically |
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changed in humans and other species. |
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Now, this massive wiring diagram, which is very simplistic because |
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it's from 1991, contains what they call the element of |
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an and first described is a sort of general structure |
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of the visual system. |
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So you covered sensory systems earlier in the course. |
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Here's your retina where light arrives on the the different |
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P and cells in your retina and passes through different |
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processing sections. |
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And right on top of that is seeing the hippocampus. |
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This is getting visual input from your eyes. |
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So what you're seeing now is getting into your hippocampus. |
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But as we're thinking out, there's a lot of processing |
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that's occurring across the entire brain before it reaches your |
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eye. |
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So there's a lot of. |
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So the hippocampus is getting information about highly, highly processed |
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information. |
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So it's doing something quite important. |
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Of course, we'll focus that today. |
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One of the key things the hippocampus is doing is |
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memory. |
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Let's dive into the anatomy a bit more. |
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Here's that picture I showed you earlier of a cadaver. |
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Here's the section where they stated The brain is really |
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microtransaction. |
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They say that these are the black dots, individual cells |
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for a human, a healthy human. |
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And what you've got in the middle here is the |
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hippocampus. |
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We've got the cortex, the neocortex on the outside. |
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And what this very simplistic story is showing us is |
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that there are all these areas in the neocortex that |
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associate information together. |
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So going back to this story here, use the retina. |
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Here is the early processing of the brain provision. |
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And then there are all these associative areas here. |
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And that's what we're looking at here. |
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Lots of information that feeds into two key areas the |
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power of the campus, our campus cortex and the prefrontal |
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cortex. |
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And I showed here in this slide, we've got the |
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prefrontal cortex here. |
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And that sends information to an area called the entering |
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cortex. |
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This bit here and then it's around the cortex, as |
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you'll get a lecture from Solomon is one of the |
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earliest areas affected in Alzheimer's disease. |
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There's a lot of interest in what this brain areas |
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doing, the various more elaborate bits in anatomy but effectively |
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the main pathway information from your eye and other senses |
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are reaching the hippocampus. |
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It's through the interactive cortex. |
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And they terminate their cells into these areas in here. |
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And we'll come on to that in more detail on |
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Friday, the anatomy that's going on inside here. |
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But suffice to say, today we're looking at this area, |
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the hippocampus in here. |
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Here's a diagram from a textbook trying to outline the |
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hippocampus and how it's linked to other areas for amnesia. |
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This blue area is the hippocampus. |
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And what we're highlighting is the meat, the temporal lobe, |
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and an immediate temporal lobe. |
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That's the corpus callosum that we now had in a |
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number of markers. |
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What we're looking at here is a circuit. |
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So the hippocampus is receiving that information of the Toronto |
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cortex. |
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The arrows are showing us that it's passing up a |
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white matter pathway equal to phonics, which occurs under the |
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white matter of the corpus callosum, and that terminates in |
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the anterior thalamus on these military bodies. |
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So when you learn your anatomy, that's kind of a |
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clear pathway through. |
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And there are also structures that come through this. |
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You can see the point axis terminating and what's known |
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as the septal nuclei in the basal forebrain. |
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So these are subcortical structures. |
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It's kind of shown within the cortical area, but there |
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are nuclei here and these then pass on to the |
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cingulate cortex. |
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And there's a generic or directly split neocortex behind the |
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corpus callosum, the spleen of the corpus callosum rupturing meaning |
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behind and spleen, you being this spleen him here of |
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the corpus callosum. |
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So these are all key areas. |
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And the reason I'm highlighting the area this way, if |
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you damage each of these areas individually or globally, you |
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will end up with someone like Clive. |
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And Clive has very, very just like extensive damage. |
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|
So amnesic patients aren't always as bad as Clive as |
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|
Deborah. |
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His wife's or the intro sequence says he has one |
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of the worst cases of amnesia. |
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But I certainly met patients who were similarly affected. |
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And so these are the key brain areas. |
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Let's walk through these and get to know them a |
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bit more. |
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|
They also come under the term paper circuit, which is |
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|
originally the scientists papers had described the circuit for kind |
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|
of motivation, emotion and memory that included these areas. |
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|
And there are two key areas, key types of amnesia |
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|
in the literature. |
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|
There's what's known as hippocampal amnesia, which is areas disrupted |
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|
by the hippocampus and the phonics. |
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|
But there's also course some easier, which is we'll see |
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|
is linked with thiamine deficiency. |
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|
There's more affected by the the bodies of the anterior |
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thalamus here. |
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So we'll mostly focus on hippocampal amnesia today. |
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|
But there are cases where they suffered a particular damage |
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|
that leads to to these particular areas. |
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|
Now, of course, the cough was the clinician that spotted |
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|
a number of cases and they all came in with |
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|
severe alcohol poisoning, really drinking an enormous amount. |
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|
They should have died, but they didn't. |
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|
But they ended up with really, really like low wearing |
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|
severe amnesia. |
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|
They didn't have hippocampal damage, but they did have in |
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|
thier anterior thalamic, miliary body damage. |
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|
And we know that these areas important from these kind |
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|
of clinical case studies that this seems to operate as |
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|
a circuit which isn't necessary, if you like to remember |
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|
what I'm saying to you. |
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|
Now if you remember what I'm saying a couple of |
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|
sentences ago, you can hear inside your head your anterior |
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|
thalamus, and you remove the bodies and the hippocampus. |
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|
So what causes amnesia? |
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|
Sometimes physical damage, head trauma or surgery? |
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|
Viral diseases are one of the common reasons you can |
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|
end up. |
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|
Encephalitis is one of the most common causes. |
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|
Other common causes are loss of blood flow, a schema |
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|
or anoxia. |
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|
When someone is, as you know, being carbon monoxide poisoning |
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|
|
is a classic example. |
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|
And finally, we talked about Corsica syndrome, which is a |
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|
|
low thymus, a thiamine is a key molecule. |
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|
|
A key molecule. |
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|
What he needs to process and do a number of |
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|
|
things for your body. |
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|
One of those is keep the brain is processing areas |
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|
in the brain. |
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|
|
Now, earlier in the course, in the end of my |
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|
slides for the first lecture, I talked about this patient, |
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|
H.M. Really classic important case. |
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|
Brenda milner is the scientist still alive in her late |
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|
hundreds and early hundreds is well over 100. |
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|
And she studied patient H.M. where he had his bilateral |
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|
temporal medial temporal lobes removed the areas we talked about |
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|
in that circuit. |
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|
Here's the diagram of his brain. |
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|
|
I mean, this is a classic case of amnesia, dense, |
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|
|
just like life. |
|
|
|
But he didn't have amnesia before surgery and after surgery, |
|
|
|
he did align the scientists to see that if you |
|
|
|
intervene with that area, you would result in that dense |
|
|
|
amnesia. |
|
|
|
Now, we can go from a very severe that's a |
|
|
|
huge amount of brain tissue to remove from somebody's brain. |
|
|
|
They do not do that anymore. |
|
|
|
They're very much, much more selective in surgery. |
|
|
|
You don't have to have that level of damage. |
|
|
|
Here's patient P.J.. |
|
|
|
Now, this is a study reported by Van and Ableton, |
|
|
|
and here's an MRI. |
|
|
|
This is from 2004. |
|
|
|
See, MRI scans clinical and it's a bit fuzzy. |
|
|
|
But what the arrows point to is an area of |
|
|
|
darkness in the sky. |
|
|
|
And what that means is water in his brain. |
|
|
|
And you can see here what looks like a nice |
|
|
|
organised brain has two kind of holes here. |
|
|
|
Unfortunately for patient B.J, they got into a fight in |
|
|
|
a bar and had a snooker cue forced through their |
|
|
|
face in a fight and it skewered the patients and |
|
|
|
misery bodies. |
|
|
|
They survived a bit like Phineas Gauge, the person on |
|
|
|
a on Bach countryside. |
|
|
|
But that patient and the period they lived after the |
|
|
|
say after having this new cookie removed and the damage |
|
|
|
alleviated has severe amnesia despite it disrupting just one small |
|
|
|
areas of brain injury bodies. |
|
|
|
If you go back to another reason that can cause |
|
|
|
amnesia is encephalitis, we can see a case study by |
|
|
|
this very famous researcher in amnesia, Larry Squire. |
|
|
|
This is Patient EPI. |
|
|
|
He's been reported in lots of studies. |
|
|
|
And this is an MRI scan of his brain. |
|
|
|
It should all look. |
|
|
|
This is a scan where the grey grey matter in |
|
|
|
the blade brain is dark. |
|
|
|
And these areas of white show where there's a lot |
|
|
|
of fluid, but the tissue is not normally presents. |
|
|
|
And effectively, this patient had a really bad case of |
|
|
|
encephalitis affecting the damage to the brain very much like |
|
|
|
patient. |
|
|
|
H.M. As if they'd had surgery to remove their hippocampus |
|
|
|
and patient. |
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|
|
EPI is extremely dense. |
|
|
|
The amnesic. |
|
|
|
Again, flipping back, you don't always have to have this |
|
|
|
extensive massive damage. |
|
|
|
Patient y are who will come on the later in |
|
|
|
this in the slides. |
|
|
|
Here's a healthy MRI scan. |
|
|
|
This is the hippocampus on a coronial section curled up |
|
|
|
nicely in the medial temporal lobe. |
|
|
|
And here it is flattened in this patient who unfortunately |
|
|
|
suffered severe carbon monoxide poisoning, just survived. |
|
|
|
It had to be revived after being revived, had quite |
|
|
|
severe amnesia really affecting their life. |
|
|
|
Finally, we can get onto Ischaemia where this is not |
|
|
|
anoxia is not like a loss of oxygen environment, but |
|
|
|
something in the body that caused a loss of blood |
|
|
|
supply. |
|
|
|
This can be a stroke, for example, very targeted stroke. |
|
|
|
And here's the healthy brain we looked at earlier, and |
|
|
|
here is the disruptors. |
|
|
|
You can see the nicely laid out cells in our |
|
|
|
in the hippocampus. |
|
|
|
This nice line of cells. |
|
|
|
We'll talk about those cells next week, sorry, this week |
|
|
|
on Friday. |
|
|
|
And here you can see this area here, nicely organised |
|
|
|
in the patient healthy brain and utterly disrupted inside this |
|
|
|
patient who had quite severe amnesia, but relatively normal brain |
|
|
|
otherwise. |
|
|
|
So amnesia can sometimes result from acts massive damage or |
|
|
|
very small amounts of damage. |
|
|
|
That's the brain. |
|
|
|
Let's turn it back to studying what happens to that |
|
|
|
brain damage. |
|
|
|
So let's look at those patients in different studies. |
|
|
|
First thing we'll look at is what can they do |
|
|
|
in amnesia? |
|
|
|
And then we'll move on to what can they not |
|
|
|
do. |
|
|
|
Think a bit more about what this tells us about |
|
|
|
long term memory and we'll pick up some controversies where |
|
|
|
there's been disagreement. |
|
|
|
So starting with spared functions. |
|
|
|
Oh, I talked to. |
|
|
|
So let's just take Clive notes, take the way he |
|
|
|
talks about to his wife. |
|
|
|
In that interview. |
|
|
|
We would say that Clive's general cognitive abilities in that |
|
|
|
interview were pretty good. |
|
|
|
His IQ seemed quite normal. |
|
|
|
It wasn't. |
|
|
|
We didn't see him do an IQ test, but I |
|
|
|
can tell you his IQ was very high. |
|
|
|
His language was entirely normal. |
|
|
|
You could hear Clive talking away, perfect prosody, very good. |
|
|
|
He was attending to what his. |
|
|
|
His wife said he could see Deborah coming in the |
|
|
|
door. |
|
|
|
He acted appropriately. |
|
|
|
We get into executive functions and the last lecture on |
|
|
|
this course, that is the ability to organise your behaviour |
|
|
|
to achieve goals. |
|
|
|
And he was perfectly fine. |
|
|
|
So you can say all that. |
|
|
|
To say, Look, we watched Clive just now. |
|
|
|
He looked entirely normal. |
|
|
|
But as a neuropsychologist, which is what we into the |
|
|
|
realm of amnesia, we want to study that. |
|
|
|
We organise psychological tasks that are quantifiable and have psychometric |
|
|
|
properties so we can we can have numbers that come |
|
|
|
out of them, we can analyse and make predictions. |
|
|
|
There's a standardised test called the Waste Weschler Adult intelligence |
|
|
|
scale, which can tell you how someone's IQ is and |
|
|
|
what their attention is like. |
|
|
|
And Clive will have been assessed and defined to be |
|
|
|
very high on this particular test. |
|
|
|
And there are other tests like the Wisconsin cause sorting |
|
|
|
task will come on to a test for executive functions |
|
|
|
and we will come back to that at the end. |
|
|
|
Again, Paul Burgess, we'll talk about this later. |
|
|
|
And then there are other things that you might show |
|
|
|
people, pictures of camels or a tiger, for example, and |
|
|
|
say, what is this animal? |
|
|
|
And if they've got a normal functioning knowledge, they will |
|
|
|
tell you what that camel is or the tiger or. |
|
|
|
And you can make that harder and harder with complicated |
|
|
|
objects that most people wouldn't know. |
|
|
|
Now, all of that makes sense. |
|
|
|
We heard Clive do all that. |
|
|
|
But what about short term memory? |
|
|
|
So we come on in these lectures, the distinction between |
|
|
|
long term memory and short term memory. |
|
|
|
Now, if Clive was able to have that conversation with |
|
|
|
Deborah and respond, she said to him, guess, guess what |
|
|
|
your daughter's up to. |
|
|
|
He had to hold that information in mind and say, |
|
|
|
I had no idea that was an appropriate answer for |
|
|
|
Clive to say. |
|
|
|
I have no idea if he blurted out elephants. |
|
|
|
That would have been absolutely make no sense. |
|
|
|
Right. |
|
|
|
He had to have heard what his wife Deborah, said |
|
|
|
and then respond. |
|
|
|
Well, he couldn't do was remember what she said in |
|
|
|
the sentence before that his daughter was getting married in |
|
|
|
another country. |
|
|
|
And so we can see that functionally in Clive. |
|
|
|
But scientists have found ways to study that you need |
|
|
|
numbers to be able to say Clive is getting worse |
|
|
|
or he's stable or or and so on. |
|
|
|
And part of the reason we need these kind of |
|
|
|
tests is we might want to know whether we want |
|
|
|
to do neurosurgery or take an intervention. |
|
|
|
You can't do that without these tests. |
|
|
|
And so one of these tasks will be span. |
|
|
|
Another is the course he blocks on. |
|
|
|
And let's take a look at the. |
|
|
|
The judge. |
|
|
|
The judges found first really simple tests developed going back |
|
|
|
to Donald Hebb and others of getting people a sequence |
|
|
|
of numbers. |
|
|
|
So what they'll do is sit with Clive and say, |
|
|
|
okay, Clive, focus on me now. |
|
|
|
I'm going to give you some numbers and tell me |
|
|
|
what you heard. |
|
|
|
And you can say Clive one four. |
|
|
|
And Clive probably say one four. |
|
|
|
Great. |
|
|
|
So he can remember the numbers one four. |
|
|
|
But if he said to Clive, okay, I'll give you |
|
|
|
one, I'll read out the list here that is used |
|
|
|
for all the clinical work. |
|
|
|
143928675. |
|
|
|
Very likely Clive might say seven five, but he wouldn't |
|
|
|
remember the numbers earlier in that sequence. |
|
|
|
He's unable to remember what the start of the sequence |
|
|
|
was. |
|
|
|
And you can do. |
|
|
|
If you have those questions. |
|
|
|
I like your point. |
|
|
|
So he seems to remember what the questions were. |
|
|
|
He said, no idea, or so you might likely remember |
|
|
|
what the question was. |
|
|
|
But you're right. |
|
|
|
After a certain number of if you gave him nine |
|
|
|
numbers is very likely to say, sorry, what is this |
|
|
|
about? |
|
|
|
And you know, he don't remember it even knows. |
|
|
|
But if you say, can you tell me the number |
|
|
|
is one to repeat back 1 to 1 two, because |
|
|
|
we heard in there. |
|
|
|
So we have very, very small digits than is what's |
|
|
|
number. |
|
|
|
So you can have a digits of one or maybe |
|
|
|
zero. |
|
|
|
If they can't hold that, that's extremely, extremely rare. |
|
|
|
Maybe someone have a digit span if they're a genius |
|
|
|
memory, sort of, you know, maybe they can remember up |
|
|
|
to 20 numbers or so, probably more if they're very, |
|
|
|
very clever. |
|
|
|
But you can do this forwards and backwards as well. |
|
|
|
So and if you're doing experiments, you might repeat numbers |
|
|
|
where people tend to get better. |
|
|
|
So hidden in a sequence of numbers, you might go |
|
|
|
through the first sequence and the next and there can |
|
|
|
be some hidden repeats, but that's not what we're getting |
|
|
|
on since the main thing is that this is one |
|
|
|
way of assessing memory amnesia. |
|
|
|
Another one is to not use numbers but just visual |
|
|
|
information. |
|
|
|
So someone has problems of language and they can't remember |
|
|
|
words or what you're saying. |
|
|
|
You can still use this visual task, which is that |
|
|
|
the patient sits opposite you across the table. |
|
|
|
If you are the clinician, you see these numbers on |
|
|
|
the blocks that the patient opposite can't see the numbers. |
|
|
|
And what the clinician will do is tap out a |
|
|
|
sequence with their fingers over the blocks and the patient |
|
|
|
has the top back the same sequence, either in the |
|
|
|
same order or in reverse order. |
|
|
|
And again, if they've got a good memory, they'll tap |
|
|
|
the right sequence through. |
|
|
|
But if it's forgotten, they'll struggle to remember what the |
|
|
|
sequence was. |
|
|
|
So this is, of course, in long span. |
|
|
|
Now, another way of looking at memory going beyond the |
|
|
|
short term test is to get into what's known as |
|
|
|
procedural or implicit memory. |
|
|
|
And there's many different types of this. |
|
|
|
So one of the key ways of studying what's known |
|
|
|
as procedural memory, we'll get on in a moment to |
|
|
|
taxonomy. |
|
|
|
The memory is to how people one of the earliest |
|
|
|
studies that came up with a way of looking at |
|
|
|
this was to say, Well, maybe there are other types |
|
|
|
of memory that Clive, that I can't remember what Deborah's |
|
|
|
asked, and he can remember how to play a piano, |
|
|
|
how And in fact, people found people like Clive could |
|
|
|
learn new tasks, procedures for doing things, but be unaware |
|
|
|
of it. |
|
|
|
So here's one classic example. |
|
|
|
In this in this psychometric task, people are shown a |
|
|
|
star on a piece of paper, but they can only |
|
|
|
see it through a mirror. |
|
|
|
So there's a piece of cardboard looking and they can't |
|
|
|
see the piece of paper directly. |
|
|
|
They can only see it through a mirror and they're |
|
|
|
given a pen and just write really simple. |
|
|
|
Can you just draw on the inner bit of the |
|
|
|
star lists that you're going to draw exactly along the |
|
|
|
stars edge and draw around it? |
|
|
|
Now, if you just looking directly at a star, you |
|
|
|
should be able, if you're most of you in the |
|
|
|
room, to be able to do that perfectly, I'd imagine |
|
|
|
all of you would do it perfectly. |
|
|
|
But if you're looking through a mirror, every move that |
|
|
|
you make is reversed. |
|
|
|
It's really hard. |
|
|
|
You've got to reverse your movements. |
|
|
|
So it's very hard. |
|
|
|
And so the average person when they're doing this makes |
|
|
|
30 errors that go outside the line 30 times, trying |
|
|
|
to make their way round the star. |
|
|
|
And if you say, Right, okay, great, you do that, |
|
|
|
and I do it again. |
|
|
|
And another session, they'll get down to say, 12 errors. |
|
|
|
You know, they'll get down and eventually you keep giving |
|
|
|
them this task by the end of the whole day. |
|
|
|
So lots of trials, they'll get down to making maybe |
|
|
|
five errors. |
|
|
|
So they've got better and better messages over the day. |
|
|
|
You get them back, the next day they'll make more |
|
|
|
errors as they've gotten a bit very quickly, they'll get |
|
|
|
back down to this and then on the third day |
|
|
|
of coming back doing this task, they're not flawless, but |
|
|
|
they're making very few errors. |
|
|
|
So. |
|
|
|
Right. |
|
|
|
And they know how to do this task and they've |
|
|
|
learned how to do mirror drawing with this particular set |
|
|
|
up. |
|
|
|
So this type of procedural memory. |
|
|
|
Now, what's amazing about this is that that score sequence |
|
|
|
you're looking at, there is not a healthy person and |
|
|
|
someone with amnesia. |
|
|
|
And the interesting thing is that they would learn how |
|
|
|
to do this pretty much just as fast as a |
|
|
|
healthy person. |
|
|
|
But on day three, they're surprised. |
|
|
|
The reason this surprise is they've never seen this before. |
|
|
|
There's no memory of sitting down. |
|
|
|
They don't know how to do. |
|
|
|
They've never seen the experience and not met the researchers |
|
|
|
to them as an uneasy, but yet they know how |
|
|
|
to do the skill suddenly got this ability. |
|
|
|
So it shows this dissociation between things you can be |
|
|
|
conscious and aware of and abilities and memories you're not |
|
|
|
conscious that you had. |
|
|
|
Another way to do this is as perceptual priming. |
|
|
|
This is devised by Elizabeth Warren's. |
|
|
|
And so this starts out as an easy version showing |
|
|
|
a white and a more difficult version shown on the |
|
|
|
left. |
|
|
|
So in this particular task, if we focus on the |
|
|
|
right hand side, the person is presented with a blank |
|
|
|
piece of paper and said, okay, we're going to turn |
|
|
|
over this to show you the next picture on the |
|
|
|
page. |
|
|
|
And I turn over the presentation with the sequence of |
|
|
|
dots or this sequence of scrambled dots and it's okay. |
|
|
|
Yes. |
|
|
|
Guess what these dots are. |
|
|
|
There are some there are some thing you can name. |
|
|
|
What are they? |
|
|
|
And if you've never done this before, you'd have no |
|
|
|
idea. |
|
|
|
If you had to guess, you might say I could |
|
|
|
be anything. |
|
|
|
Could be the house, could be anything. |
|
|
|
I don't know. |
|
|
|
But then they flip the page over to the next |
|
|
|
image and they say, What do you think this is? |
|
|
|
I know it's not a house. |
|
|
|
Something else Maybe you don't know exactly. |
|
|
|
You cannot guess what that might be. |
|
|
|
Okay, look it over again. |
|
|
|
Now it's getting a little clearer what this might be. |
|
|
|
And on the last page, you flip over and. |
|
|
|
Okay, okay. |
|
|
|
If the person's got normal memory, normal functions that he |
|
|
|
hasn't caused us an elephant. |
|
|
|
I can name the elephant. |
|
|
|
Okay. |
|
|
|
So they get they can name the elephant on the |
|
|
|
last page. |
|
|
|
What the clinician will do is repeat this again and |
|
|
|
say, okay, here's. |
|
|
|
And they'll do that with a whole load of animals. |
|
|
|
So you're not just getting one elephant, you're getting you're |
|
|
|
getting a seagull or a canoe or whatever. |
|
|
|
It's just those little dots. |
|
|
|
And so the person might see this and say, Is |
|
|
|
it the canoe? |
|
|
|
No, they're wrong. |
|
|
|
And I go forward and I say, Is it the |
|
|
|
elephant? |
|
|
|
Yes, it's the elephant. |
|
|
|
They've learned that that sequence of dots. |
|
|
|
And if you do this again and again, this time |
|
|
|
they see this this sequence in dogs. |
|
|
|
They can say elephants. |
|
|
|
Now, they don't necessarily know. |
|
|
|
Sometimes they might know, but they might not necessarily know |
|
|
|
why This feels like it's the elephant, particularly this one |
|
|
|
here, because it's really difficult to guess. |
|
|
|
But the key point of this work is that amnesic |
|
|
|
patients likewise can still do this. |
|
|
|
He can still guess well above chance that that sequence |
|
|
|
of dots is an elephant. |
|
|
|
And he's surprised again. |
|
|
|
No idea how he knows, but his brain has learned |
|
|
|
to associate those dots with elephants. |
|
|
|
And what's been shown is that that involves areas of |
|
|
|
neocortex and other areas of the brain that are not |
|
|
|
the hippocampus. |
|
|
|
Hippocampus can help because you can remember things, but this |
|
|
|
type of rapid naming of dots can be done by |
|
|
|
other brain areas. |
|
|
|
So you can do this in amnesic. |
|
|
|
Another classic is before we move on to the other |
|
|
|
things that are lost. |
|
|
|
Example of preserved. |
|
|
|
Yeah. |
|
|
|
If you're you to. |
|
|
|
He only played one time. |
|
|
|
He could only play what he'd learned there. |
|
|
|
It's very difficult to learn new sheet music, as far |
|
|
|
as I know. |
|
|
|
I don't. |
|
|
|
I don't. |
|
|
|
There's a whole Wikipedia page all about Clive, and he |
|
|
|
may well tell us whether he has learned, but my |
|
|
|
memory is that it's this type of learning can be |
|
|
|
done. |
|
|
|
And a good point is, if you came back to |
|
|
|
Clive in a month's time and said, Right, can you |
|
|
|
name this elephant? |
|
|
|
He's already forgotten that. |
|
|
|
But have also had many normal, healthy people. |
|
|
|
Like if I came back to you in a year's |
|
|
|
time and said, Right, what was that? |
|
|
|
With these dots, you might remember if I was only |
|
|
|
an elephant I showed you. |
|
|
|
But if I showed you a whole ton of animals |
|
|
|
and things, you wouldn't remember it. |
|
|
|
This is something in the immediate area of learning. |
|
|
|
But yeah, it's a good question. |
|
|
|
As I say, I don't know the exact answer, but |
|
|
|
it's very likely he couldn't learn. |
|
|
|
And again, the challenge is finding styles, specifically tasks. |
|
|
|
You can go metrics and numbers out. |
|
|
|
So here is a task developed by Barbara Knowlton and |
|
|
|
others published in Science some time back and has been |
|
|
|
reused in lots of studies, and they tested it on |
|
|
|
both patients with Parkinson's, Huntington's or amnesic cases, the brains |
|
|
|
of different patients. |
|
|
|
And what they found was that what they did in |
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|
|
this ask is take a sequence of cards that only |
|
|
|
show one of these at a time and a whole |
|
|
|
sequence of these cards for these cards. |
|
|
|
But they keep flipping through them and saying, okay, when |
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|
|
you see a card, let's take the latest item. |
|
|
|
And you say, okay, what with each of these cards |
|
|
|
is going to give you, you going to have to |
|
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|
guess whether it's going to be sunny or rainy today |
|
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|
based on the card. |
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|
And then they guess you might say, well, I've no |
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|
|
idea, but I'm going to get some. |
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|
And they're told, yes, you're right, that son. |
|
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|
And he's the son. |
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|
Perfect. |
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|
Okay. |
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|
|
Next card, son. |
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|
Right. |
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|
They said, Well, you guessed right. |
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|
And I've been told, no, you're wrong, that that was |
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|
done. |
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|
And they go and they see the cards and they |
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|
|
have to learn what the association is between a card |
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|
and an outcome. |
|
|
|
And of course, this goes back to our reinforcement learning |
|
|
|
lecture last week where I talked about the idea. |
|
|
|
If you watched the movie of the idea that you'd |
|
|
|
need that motivational circuit, the dopamine to learn this association. |
|
|
|
And so what's really important here is that it's not |
|
|
|
100% probable. |
|
|
|
So if you given this card 80% of the time, |
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|
|
it will lead to say something and 20% it will |
|
|
|
be right. |
|
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|
So you can't by using one shot experience memorise, you've |
|
|
|
got to learn over lots of trials. |
|
|
|
What each card is associated with. |
|
|
|
All of them will give you some rain. |
|
|
|
But these two, for example, might give you some more |
|
|
|
of the time. |
|
|
|
And these. |
|
|
|
Right more of the time and was exciting and why. |
|
|
|
This is published in one of the world's leading science |
|
|
|
journal Science was that amnesic patients could have learned that |
|
|
|
rule over 50 trials. |
|
|
|
They could they could learn what this is they don't |
|
|
|
get as an doctor. |
|
|
|
Guess some well done Huntington's and Parkinson's patients. |
|
|
|
Damage destroys them. |
|
|
|
And about the last week, they struggle to learn that |
|
|
|
rule their VCA, that whole circuit to do it opening |
|
|
|
is disrupted the VCA and that circuit is not disrupted |
|
|
|
and classic amnesia. |
|
|
|
And so what was fascinating was that they got this |
|
|
|
dissociation between amnesia able to learn, and Parkinson sometimes is |
|
|
|
not able to learn. |
|
|
|
But when you test them an hour later, have you |
|
|
|
seen these stimuli? |
|
|
|
Which of these eight cards and there's four of these |
|
|
|
and four other ones did you look at Parkinson's patients |
|
|
|
and Huntington's? |
|
|
|
Yeah, it's obvious it was. |
|
|
|
I spent ages looking at these cards as these four. |
|
|
|
They know what they saw. |
|
|
|
They can recognise the stimuli, but Clive Waring and other |
|
|
|
amnesia patients would have no idea that they seen these |
|
|
|
cards. |
|
|
|
So you have this association with learning a rule and |
|
|
|
being able to remember the stimuli. |
|
|
|
What did you see before you recognise it? |
|
|
|
So this this is this is this implicit with this |
|
|
|
learning of the rule is described as habit learning. |
|
|
|
Like your brain is constantly learning habits all the time, |
|
|
|
sitting down, setting up laptops where you turn to when |
|
|
|
you leave this. |
|
|
|
You been in lectures here lots of times. |
|
|
|
You're not thinking very hard about where the doors are. |
|
|
|
You have a habit ingrained in your brain. |
|
|
|
That's what's the amazing things that are stated in these |
|
|
|
amnesic patients. |
|
|
|
But what is lost? |
|
|
|
Okay, so we're going to measure that. |
|
|
|
What appears to be lost is cut encapsulated by this, |
|
|
|
what's known as episodic memory. |
|
|
|
Memory for events and episodes which were personally experienced. |
|
|
|
The things that happened to you. |
|
|
|
So, Clive, to go back to that video I showed, |
|
|
|
Deborah asks him and says, I'm going to tell you. |
|
|
|
Let me tell you, divorce is getting married. |
|
|
|
She's getting married. |
|
|
|
Australia. |
|
|
|
She's getting married soon. |
|
|
|
I'm trying to remember exactly what he said. |
|
|
|
I'm sure I didn't get it right, but that is |
|
|
|
the gist of it. |
|
|
|
He's then tested on. |
|
|
|
Well, do you remember what's happening tomorrow? |
|
|
|
He has no idea. |
|
|
|
So he's failed to remember. |
|
|
|
And she asked him several questions. |
|
|
|
He can't remember any of them. |
|
|
|
This all comes under episodic memory, personally presented events, information |
|
|
|
that was given to him or episodes made or experience |
|
|
|
that he experienced himself. |
|
|
|
Episodic memory. |
|
|
|
Now, there's two types of amnesia when we delve down |
|
|
|
into this. |
|
|
|
What we've just looked at was anterograde amnesia. |
|
|
|
So Clive Waring had a lesion in his brain, and |
|
|
|
this is his life after that lesion. |
|
|
|
His inability to remember whatever his wife is telling him |
|
|
|
is known as an interim great amnesia. |
|
|
|
He can't remember that his daughter's getting married and told, |
|
|
|
but he might remember that he has a daughter. |
|
|
|
He wasn't surprised as my daughter's getting married. |
|
|
|
I have a daughter. |
|
|
|
Do I really have a daughter? |
|
|
|
He didn't say that. |
|
|
|
Except that he knew he had a daughter. |
|
|
|
There's no loss of memory he could have. |
|
|
|
There's all sorts of things that Clive knows about happened |
|
|
|
in the past. |
|
|
|
But there's a period typically in amnesia just close to |
|
|
|
the lesion where he had his damage. |
|
|
|
But perhaps, for example, let's say his daughter, this is |
|
|
|
this is a fictitious narrative. |
|
|
|
It's something that happened to his daughter. |
|
|
|
This quite significant just before his lesion, his brain damage |
|
|
|
is quite likely. |
|
|
|
He would not remember that. |
|
|
|
And whenever his wife brought it up, he'd be surprised. |
|
|
|
And what's important here is that his brain was perfectly |
|
|
|
healthy when he learned that information, but it had not |
|
|
|
been stored in some way that made it. |
|
|
|
Safe or protected. |
|
|
|
Where is the memory that he has a daughter from |
|
|
|
some time back in his life when he was an |
|
|
|
adult has been protected. |
|
|
|
He has retained that despite their amnesia. |
|
|
|
So you have some retrograde and there's constant anterograde amnesia |
|
|
|
in the classic amnesia syndrome. |
|
|
|
So how do we test the I'm sorry, great amnesia? |
|
|
|
Let's focus on how we test that on the classic |
|
|
|
test. |
|
|
|
To do that, to look at episodic memory in a |
|
|
|
laboratory or at a clinic is to give people this |
|
|
|
task where you're shown a abstract picture like this, isn't |
|
|
|
it? |
|
|
|
Is the real stress complex figure based on the clinicians |
|
|
|
that develops it and they give it, the person is |
|
|
|
given another piece of paper. |
|
|
|
And so can you draw this out as carefully as |
|
|
|
you can, do this really carefully? |
|
|
|
Drew exactly what you see on this paper, nothing else. |
|
|
|
And then after 50 minutes, they're given a blank piece |
|
|
|
of paper. |
|
|
|
And so, okay, I showed you a piece, a drawing. |
|
|
|
Please, can you redraw that? |
|
|
|
And again, Clive would have no idea that he has |
|
|
|
a drawing or something, but sometimes the amnesic have some |
|
|
|
sense they had too. |
|
|
|
Earlier on, I showed you patient brain with really small |
|
|
|
selective damage. |
|
|
|
Here's on the far right of this nine he's is |
|
|
|
a control participant who's drawn out the shape. |
|
|
|
Each of these are patients with a brain with really |
|
|
|
severe damage. |
|
|
|
They've all drawn that shape perfectly relatively perfectly. |
|
|
|
And the control participants and a fantastic job, they've drawn |
|
|
|
it themselves. |
|
|
|
So they they've got a better memory than if you |
|
|
|
just seen the picture. |
|
|
|
You can see they've gotten the lines across. |
|
|
|
Yes, they're not perfect. |
|
|
|
But each of these participants here, they've remember these are |
|
|
|
amnesic patients. |
|
|
|
And remember something arises. |
|
|
|
And that in itself is kind of fascinating. |
|
|
|
That is something, remember, for retained, but a vast amount |
|
|
|
is lost. |
|
|
|
So there seems to be some preserved information about this |
|
|
|
going into that's very likely. |
|
|
|
Is that implicit memory for something about the context of |
|
|
|
that. |
|
|
|
But it's a great question as to why we still |
|
|
|
don't fundamentally understand all the things that occur in amnesia, |
|
|
|
and that would be an example of it. |
|
|
|
Semantic memories. |
|
|
|
You got that memory for Clive. |
|
|
|
What was he told in that short chat with his |
|
|
|
wife? |
|
|
|
Another memory type that's really key is the ability to |
|
|
|
remember facts information independently from the initial experience. |
|
|
|
So an example of that is knowing what is this |
|
|
|
for English speakers and people in the room? |
|
|
|
You're hearing this lecture in English. |
|
|
|
So you should know that this this diagram here is |
|
|
|
a tiger. |
|
|
|
That's the knowledge you gained over many experiences. |
|
|
|
Now, it's unlikely that you remember the first time you |
|
|
|
learn Tiger. |
|
|
|
You may do, but many people have grown up in |
|
|
|
the first languages. |
|
|
|
English Well, I had no idea when I learned I |
|
|
|
was very young. |
|
|
|
John Another example one was the capital of Peru is |
|
|
|
a fact. |
|
|
|
I also have no memory of when I first learned |
|
|
|
that Lima is the capital of Peru. |
|
|
|
So there's much later in life, there's still, for me, |
|
|
|
a semantic memory. |
|
|
|
I have no idea when I learned that site. |
|
|
|
These are just classic examples. |
|
|
|
Clive Waring in that interview knew what a daughter was. |
|
|
|
He was straight in questions. |
|
|
|
A lot of the things he has, a lot of |
|
|
|
facts he knows about the world and these are retained. |
|
|
|
And Larry Squire, who I put his picture up next, |
|
|
|
the patient NPR there. |
|
|
|
In fact, Larry Squire, there's a short 50 minute movie. |
|
|
|
And this section you can watch where he talks through |
|
|
|
declarative memory and taxonomies of memory and history of amnesia. |
|
|
|
It is quite helpful if you want some more information. |
|
|
|
But here, what was developed by Larry Squire and many |
|
|
|
others, Neal Cohen is an example. |
|
|
|
The key person here was that long term memory can |
|
|
|
be split between explicit memory he describes as declarative memory, |
|
|
|
an implicit memory or non declarative memory. |
|
|
|
So explicit memories are things like Clive Clive wearing saying, |
|
|
|
you know, I do, I do know this or I |
|
|
|
don't know that my daughter's getting married tomorrow. |
|
|
|
Yes, you can. |
|
|
|
You can say yes or no to that. |
|
|
|
But how did he play the piano? |
|
|
|
It's not a yes, no question. |
|
|
|
He used to move his fingers in a particular way. |
|
|
|
He could tell you what is happening, but he just |
|
|
|
knows how to do it. |
|
|
|
It's like riding a bicycle. |
|
|
|
You don't really think about it. |
|
|
|
You just kind of do it. |
|
|
|
And that's what's described here is non declarative skills and |
|
|
|
habits and emotional responses to things like priming that can |
|
|
|
occur, knowing that that was an elephant given the dots. |
|
|
|
So how did you know that? |
|
|
|
I just know might be the answer. |
|
|
|
And within declarative memory, we're drawing a distinction between episodic |
|
|
|
memory events and times, the things that happened, and semantic |
|
|
|
memories of facts and figures and things. |
|
|
|
And the controversy will now look at. |
|
|
|
So that's that's the kind of where we got to |
|
|
|
in general agreement these things will exist and that there |
|
|
|
are this side of the pathways, damage and amnesia. |
|
|
|
Going to end the lecture and the last 8 minutes |
|
|
|
or so on controversies. |
|
|
|
And one of them has been the brain areas involved |
|
|
|
in supporting recognition, memories, semantic memory. |
|
|
|
So here, if we look down here, the events of |
|
|
|
episodic memory. |
|
|
|
You can split if your scientist in two things, you |
|
|
|
can recollect, go back in time and remember and say, |
|
|
|
Yeah, I was in this lecture theatre in the past. |
|
|
|
It was on a monday. |
|
|
|
I remember that. |
|
|
|
Or you can say you were familiar. |
|
|
|
So what classically might be meeting somebody and knowing what |
|
|
|
their name is and who they are versus meeting somebody? |
|
|
|
You think I know you, but I don't know what |
|
|
|
your name is or who you want to know how |
|
|
|
I know you, but I just know who you are. |
|
|
|
And that's the similarity. |
|
|
|
Now, some of the work is shown, and I just |
|
|
|
highlighted that example, a feeling of knowing that's what this |
|
|
|
slide is running over. |
|
|
|
An example here is recognising someone you seen before, not |
|
|
|
knowing the name of who they are. |
|
|
|
Now, that's fine, I can tell you that. |
|
|
|
But if I want to do a test badly, one |
|
|
|
of the key forefathers of like a lot of working |
|
|
|
memory and neuropsychological assessments developed the task of the two |
|
|
|
and people test. |
|
|
|
We have to remember people in names or visual shapes |
|
|
|
of an either figure or you have to do a |
|
|
|
recognition task. |
|
|
|
You are given a spotlight, a whole sequence of names |
|
|
|
like Jill, Ashley or Doors to memorise really boring doors. |
|
|
|
Unless you are tested on that always, you can recognise |
|
|
|
those names. |
|
|
|
The reason you estimate this side really hard is that |
|
|
|
you want us to equate record recall with recognition. |
|
|
|
And we're much better recognition because the information's in front |
|
|
|
of us. |
|
|
|
I was shown here are a number of patients, so |
|
|
|
with this test, the rules and people is standardised. |
|
|
|
The score of ten is normal and plus or minus |
|
|
|
two captures. |
|
|
|
And those people I was shown in prior work. |
|
|
|
Is that patient? |
|
|
|
We are on another case. |
|
|
|
This patient John, we're amazingly good if we are really |
|
|
|
good are recognising which of these doors you give that |
|
|
|
door and they pick it out. |
|
|
|
You can even see the colours change the bit. |
|
|
|
They recognise this door from having seen 12 doors with |
|
|
|
that particular door really good at it and patient John |
|
|
|
Similar, but they cannot remember the name. |
|
|
|
So the fact this guy's call, Tom Webster utterly forgotten, |
|
|
|
absolutely devastated on the on recall side are the patients |
|
|
|
suddenly have terrible on both scores. |
|
|
|
So what what it shows is generally amnesia damages both |
|
|
|
the ability to recognise things like names and pictures and |
|
|
|
recall things. |
|
|
|
But sometimes the damage can be selective and preserve, says |
|
|
|
some other areas of the brain must be doing this |
|
|
|
recognition memory. |
|
|
|
And that's been somewhat controversial. |
|
|
|
Controversial? |
|
|
|
The argument is the hippocampus is not essential. |
|
|
|
This brain area for tasks using familiarity. |
|
|
|
What about semantic memory? |
|
|
|
So if I'm going around the world like Clive and |
|
|
|
trying to Deborah sitting there, trying to teach Clive about, |
|
|
|
say, what a tsunami is. |
|
|
|
So it's anomalies are not really discussed in the literature, |
|
|
|
in the culture before a certain point. |
|
|
|
Big tsunamis came in and killed lots of people and |
|
|
|
culture. |
|
|
|
So this Endeavour might be trying to explain to Clive |
|
|
|
all about tsunamis. |
|
|
|
And he's going have a really hard time remembering what |
|
|
|
a tsunami is. |
|
|
|
And eventually, with all the research shows, he will never |
|
|
|
learn new facts. |
|
|
|
Clive is so densely amnesic, he can't learn new science |
|
|
|
information. |
|
|
|
So H.M. |
|
|
|
He talked about his famous patient. |
|
|
|
He could not remember new word definitions being done. |
|
|
|
And the other patient I talked to about both episodic |
|
|
|
and semantic information, they can't learn new things. |
|
|
|
However, there was a startling discovery in 1997. |
|
|
|
Away from, in fact, pretty much in the offices where |
|
|
|
the lecture Friday is Fridays lectures at the Institute of |
|
|
|
Child Health. |
|
|
|
Finally, Volker Kardon is a client, is the lead clinician |
|
|
|
for the clinical neuropsychology team for the paediatric pathway in |
|
|
|
the ICU in Great Ormond Street. |
|
|
|
And her team led the discovery in 1997 of a |
|
|
|
group, a number of patients who couldn't remember anything like |
|
|
|
Clive come in, no memory, couldn't get a cup of |
|
|
|
tea. |
|
|
|
They forget who you are. |
|
|
|
Yeah, I had amazing knowledge about the world. |
|
|
|
And one of those patients I mentioned a second ago |
|
|
|
was John, this patient, John. |
|
|
|
John went on to pass a GCSE in history. |
|
|
|
You got a He didn't get an A-grade, but he |
|
|
|
remembered lots of facts. |
|
|
|
Somehow this patient, John, had learned over repeated, repeated repetition |
|
|
|
facts about the world. |
|
|
|
What this tells us is that the neocortex, John, John |
|
|
|
and all these patients has severe hippocampal damage. |
|
|
|
My patient, while John's hippocampus was shrunken, the key thing, |
|
|
|
the word his early onset, all of them had damaged |
|
|
|
in childhood, really early in life. |
|
|
|
So these are their their neocortex, the survival supplies for |
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this gradual learning, or there's something about their hippocampus when |
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damaged early in life, still able to pull off this |
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trick. |
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You still don't know the exact mechanism. |
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It's very hard to study in humans, these things. |
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So this has been controversial and caused a lot of |
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disagreement. |
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But the current no doubt there's no dispute. |
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These children have grown up with eyes and memory and |
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can't remember what happened to them over their lives in |
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terms of experiences they don't know facts about. |
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They know they got a brother, for example, but they |
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don't. |
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You said, Don't you remember your 14th birthday when Joe |
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came and it was a disaster? |
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No. |
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No memory. |
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Most people remember the disastrous birthday they might have had. |
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They won't have that ability. |
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Finally, I'm going to touch on the last moments of |
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this lecture on consolidation. |
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So here's patient H.M. Here's the dense. |
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I'm Terry Great amnesia. |
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He had utterly after the surgery he lost all capacity |
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to learn new things. |
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But they asked him questions before the surgery and just |
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before it. |
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Very few details. |
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But you go back into his childhood and he could |
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remember. |
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So he lost. |
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He lost the memory of an uncle who died very |
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sadly. |
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And his childhood memories are fantastic. |
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What was argued around from that information was that it |
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seems like the hippocampus in that circuit we've been looking |
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at is damaged in amnesia, is critical for inquiry into |
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memories. |
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But then over time that becomes consolidated. |
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Consolidated is strengthened. |
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Those memories become strengthened and stored in a much more |
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robust way, and then they become independent of the hippocampus. |
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So let's take another patient. |
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So that was H.M. But here's a patient p Z |
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who had a diary. |
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He kept a meticulous diary. |
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So you can go back and work out how much |
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of his diary did he remember and what matters. |
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And Sir Mark showed in a paper study was that |
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it was like up and up linearly. |
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I just went up backwards over time. |
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And there are a range of ways to probe this |
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with a diary or with photographs of famous people. |
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If you're an American, these are famous celebrities. |
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You might recognise one or two if you're lucky, and |
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there are standardised ways of interviewing people as highlights. |
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So most of these suffer from some retrograde amnesia, but |
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it's variable pace, I think is a case of patient |
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RB Where we went a few years back, another case |
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l.D. |
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This famous face, no memories their entire life back to |
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childhood. |
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It's hard to study few standardised tests if you're not |
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motivated, it's very hard to study and all the stimuli |
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are very hard to match how salient they are. |
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And it's hard to know whether those memories are going |
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back up and synthesised or episodic. |
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So that's one of the other debates. |
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And what scientists think is going on is that when |
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you first acquire memory, your neocortex or go back to |
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that slide on the hippocampus, the neocortex, signs of. |
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Mason is at the campus and creates links and binds |
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together information between areas in the neocortex, which, of course |
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talk to each other, connect connections between the cells. |
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|
But over time, these connections between these great areas become |
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strengthened and able to operate, and the connections with the |
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hippocampus become downregulated not necessary for the retrieval of the |
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|
memory. |
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|
And that's that is the standard model of consolidation. |
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|
Very simple model that if you remember things initially, like |
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H.M. learns that he's got a uncle, he's who's died |
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very sad. |
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He uses hippocampus to bind it, but he then has |
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|
his hippocampus removed. |
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It doesn't have a chance to strengthen or the fact |
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|
there was a fire in his and his in his |
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an environment of his young really early along back in |
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his childhood. |
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It does get strengthened and he can remember it because |
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his neocortex has got that memory strengthened and consolidated. |
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|
Now that was argued against in 1997 by two scientists, |
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|
Maurice Moscowitz. |
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|
And then they tell you argue that actually the details |
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and never really there. |
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If you go back to these kind of the pollen |
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and the fire is not detail in nature and cannot |
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tell you when you could when he was alive about |
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the details of it that in fact, as we get |
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as things go on, they argue the visual details get |
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strengthened with the hippocampus and MCO, the medial temple who |
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|
are strengthened. |
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|
That view was updated in 2011 in this journal article |
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|
by Whittaker Moskovitz to argue that there's a transformation that |
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|
occurs in the brain for detail. |
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|
And here's just one case example from Pelosi and colleagues |
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|
who are on the case who absolutely could not recall |
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things from their life, the detail they could recognise, not |
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|
the things that happen to them. |
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|
So we can see this distinction between vivid, rich detail |
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|
of recall and massive dishonesty and retrograde amnesia. |
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|
But there's no gradient, and it's this episodic loss that's |
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|
occurring. |
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So I'm just going to end on a few last |
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|
points. |
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|
Let's take an example of this kind of consolidation. |
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|
This is an amnesic taxi driver. |
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|
I was fortunate to study with Eliot and McGuire at |
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|
UCL. |
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|
He was hippocampus, was disrupted bilaterally, very severe damage damages, |
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|
hippocampus like Clive wearing. |
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|
I stepped out to get him a cup of tea |
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|
and came back. |
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|
He reintroduced himself to me and said Hello, but we've |
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|
been talking for some time. |
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|
I gave him I gave him the compass with an |
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|
arrow on it. |
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|
He couldn't see the compass. |
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|
It was hidden so I could measure his direction pointing. |
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|
I just I could just point to various places around |
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|
London. |
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|
We're standing in the middle of Queen's Square. |
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|
Where is London Bridge? |
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|
I'd be very surprised if you do see it. |
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|
The audience could point from here to London Bridge. |
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|
I can't do it if you take a London taxi |
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|
driver. |
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|
He spent 40 years. |
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|
He knows exactly about London Bridge. |
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|
He knows where Peter Street is. |
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|
He knows where all the streets in London, they have |
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|
|
to memorise it to be London taxi drivers. |
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|
And this is the chart. |
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|
A little little white dots of all the taxi drivers |
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|
with healthy brains we measured on in the black dots |
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|
this amnesic and he doesn't know how he knows this, |
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|
but he knows these directions. |
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|
We then were able to put him into a virtual |
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|
reality simulation of London back in 2006 and have him |
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|
drive round a virtual simulation of London. |
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|
And here's a route driven across the virtual simulation by |
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|
a group of ten healthy cat taxi drivers. |
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|
And in black. |
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|
Here's his route. |
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|
So it was terrible. |
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|
He was really bad at actually navigating. |
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|
So we had this knowledge of things, but his ability |
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|
|
to actually find his way in London in a virtual |
|
|
|
simulation was terrible. |
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|
|
And what we found was that if he had to |
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|
go on minor roads, he couldn't remember. |
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|
But the major A-roads he could had been consolidated. |
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|
So he had this. |
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|
Some of his knowledge that we repeated have been strengthened. |
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|
Finally, Demis Hassabis, who was in Newcastle before he's founded |
|
|
|
the company DeepMind, ran some studies asking patients to imagine |
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|
|
things like, Can you imagine lying on a sandy beach? |
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|
If you ask most people's room, they'll give you a |
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|
|
long, long description, all sorts of things happening. |
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|
But if you ask Clive Waring or patients, he was |
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|
tested. |
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|
They gives you a bit of a vague answer. |
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|
They report various things, but it's a bit vague. |
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|
|
And in particular they're missing all of the references to |
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|
|
where things are, things the normal, healthy person. |
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|
Things are behind them and they're left there. |
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|
But this is all missing. |
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|
And what damage some of the elements. |
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|
They can't actually imagine the scene. |
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|
You can imagine objects like a football. |
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|
They have problems processing, constructing the world. |
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|
|
So what this means is that where we are in |
|
|
|
2022, the hippocampus is necessary for amnesic to remember things, |
|
|
|
but it goes into imagination as well. |
|
|
|
Clive Waring would not be able to imagine his daughter's |
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|
|
wedding. |
|
|
|
This is what this work shows. |
|
|
|
So here's the overview of what we talked about today |
|
|
|
for time. |
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|
|
I won't read it out and can't read this and |
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|
|
there's a great review in 2008. |