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Reconstructive Memory
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Memory – Disorders and Brain Damage
In this course, Dr Ashok Jansari (Goldsmiths, University of London) explores memory in the context of brain damage and memory disorders. In the first lecture, we think about reconstructive memory by understanding the process of remembering not as locating a ‘file’, but as a reconstruction of sensory data, contextualised as an event. In the second lecture, we consider how people differ in their memory performance and where these differences might originate. Next, we look at some key figures in memory psychology, who have helped shape our understanding of which brain areas are responsible for which aspect of memory performance. In the fourth and final lecture, we discuss dementia as an umbrella term for degenerative brain disorders and some of the current research looking to improve our diagnostic ability and potential for curing these conditions.
Reconstructive Memory
In this lecture, we think about reconstructive memory, focusing in particular on: (i) how the actual reconstructive nature of memory differs from the ‘filing system’ of memory that is commonly thought to be representative; (ii) the role of engrams as a store of combined sensory data; (iii) a real case study of an individual demonstrating improper memory reconstruction as a result of an aneurism, as well as Alexander Luria’s ‘S’ case study, who was able to recall one hundred written numbers ten years after they were originally shown them.
Hello.
00:00:07I'm Dr Ashraf Ghani. Sorry.
00:00:08And I'm a cognitive neuropsychologist at Goldsmiths University of London.
00:00:09In this lecture, I'm going to be talking about different aspects of memory.
00:00:15And in this first section,
00:00:19I'm going to be talking about reconstructive memory.
00:00:20Reconstructive memory is really interesting because most people
00:00:24think memory is like a filing system where you
00:00:28go into your memory system like a hard drive and find what you did on Tuesday,
00:00:31the 12th of February, 2015.
00:00:36But in fact, that's not how memory works.
00:00:39Memory is actually a reconstructive process.
00:00:42And the way it works is that when you're experiencing something,
00:00:45so right now you're hearing me you're seeing me,
00:00:49you might be have emotional feelings.
00:00:53You might have a taste from something you've just eaten, etcetera.
00:00:56Your brain takes those five different senses and your emotions
00:00:59from the different parts of the brain where their first processed
00:01:05and puts them together
00:01:09and puts them together into a packet.
00:01:10And that packet is
00:01:12the site, the sound that taste the feeling, et cetera of your current experience.
00:01:15And it creates some sort of what we call an engram,
00:01:22which is that combination of different centres and feelings,
00:01:27and it stores those away
00:01:31now rather than us looking for it when we're
00:01:34trying to remember something as a filing system.
00:01:37What we think actually happens is that we
00:01:40try to reconstruct what could have happened.
00:01:44So in fact, memories actually
00:01:47this process where we try to create what we think happened
00:01:50and hopefully get it right now we know that this is the
00:01:55case because of errors that happen when we try to recall things.
00:01:58There's a classic experiment by Bartlett where he got
00:02:03people to recall or read something about ghosts.
00:02:06I think it was.
00:02:10And then he asked them to recall it a number of times,
00:02:12and what he found was that people
00:02:16were remembering something that hadn't actually happened,
00:02:19and the reason for that is they were storing it in their own way,
00:02:23the bits that they understood.
00:02:28And then later on, when they were trying to find that information,
00:02:29they were making errors because of the fact that they were reconstructing.
00:02:35And some people are good at reconstructing and other people are not.
00:02:40And in general parlance, we talk about people who got good memory.
00:02:44People have got poor memory
00:02:49and part of that difference is to do with the ability to reconstruct.
00:02:51Now we can actually see this with brain damage so we can see
00:02:56from patients with certain types of brain
00:03:01damage that this reconstruction is happening.
00:03:03So, for example,
00:03:07many years ago I worked with a famous patient in Iowa who had an aneurysm,
00:03:08and an aneurysm is a particular type of blockage within an artery,
00:03:14which creates problems within the brain and can actually kill someone.
00:03:20Thankfully, with this patient, that aneurysm was dealt with.
00:03:25But as a result of this, he did result get some brain damage.
00:03:30And after surviving this,
00:03:36this patient
00:03:39known as R. F. Came up with the most bizarre memories.
00:03:40So, for example, he claimed to have been the commander of the space shuttle.
00:03:45He also said that he had been to the funeral of the president of Egypt.
00:03:50Now all of this could have been possible. He might have been an astronaut.
00:03:56Astronauts are important people. They get invited to famous important events.
00:04:00But in fact he was a postman in Iowa
00:04:06and he hadn't been in the space shuttle. He hadn't been to, um,
00:04:09Anwar Sadat's funeral,
00:04:15so we did a study where we looked at whether he was just coming
00:04:16up with these bizarre stories or whether there was something else going on.
00:04:21So we created a study where we told him
00:04:25a number of stories which were developed to make sure
00:04:28that we knew what was inside each of the
00:04:33stories and that there was different to one another.
00:04:35We told him the stories
00:04:38allowed him to read the stories,
00:04:40and then we tested his memory one hour later, one day later, one month later,
00:04:42etcetera.
00:04:48And what we found
00:04:49was that initially
00:04:51he had some of these memories.
00:04:53But he was coming up with this.
00:04:55What initially looked like bizarre recalled and bizarre memories.
00:04:57But in fact it was bits of story,
00:05:02one mixed in with bits of story three mixed in with story five.
00:05:05So overall it looked like a bizarre
00:05:10made up story.
00:05:14But in fact it was bits of things that he
00:05:16had experienced being put them together in an incorrect way.
00:05:18So from examples like that,
00:05:24people with brain damage but also the types of errors that we can make,
00:05:27like in the Bartlett study or there's been
00:05:31more recent studies by stayers and hammer.
00:05:34What we see is that memory is a process of creating what could have happened,
00:05:38and then we have a checking system and that
00:05:45checking system is in the front of the brain.
00:05:48And that checking system
00:05:50says,
00:05:52Could I have been the commander of the space shuttle?
00:05:53And that check sing system under normal circumstances works,
00:05:57and it prevents someone from coming out with the bizarre memory.
00:06:02So when you try to remember what to happen for your last birthday,
00:06:06what your brain does is say, OK, what did I probably do for my last birthday?
00:06:10Was I in the country? Was I away?
00:06:16Did have a party at home, or did I meet people in a nightclub?
00:06:18What was I likely to have done which of my friends were around?
00:06:23And you reconstruct that memory and then you're the front of your brain,
00:06:27evaluates it to try to work out whether it could have happened or not.
00:06:32And we all make errors,
00:06:37so you'll have had the experience where you're talking to
00:06:38your friends about a holiday you went on or some
00:06:42party you went to and you'll say something about so
00:06:45and so having been there and your friend says,
00:06:48Actually, no, Nadia wasn't there.
00:06:50She wasn't in the country at the time.
00:06:52What's happening there is that your reconstruction has created some errors,
00:06:56and your friend is correcting that.
00:07:01And that's completely normal. But you wouldn't come up with on my last birthday.
00:07:03I went into space because your brain will stop you from doing that.
00:07:09So what we see here with reconstructive memory
00:07:13is very good evidence that memory isn't a filing system.
00:07:17Where something happens, you store it,
00:07:22and then later on, you just go and pick it out and read off of that document.
00:07:25In fact,
00:07:30memory is this process where you try to reconstruct what happened originally,
00:07:31your brain unconsciously, you're not aware of this.
00:07:37Your brain tries to evaluate whether that could have happened,
00:07:40and then it kind of tweaks things until it's happy with it,
00:07:44and then you output it as your memory.
00:07:48So the thing to take away from this
00:07:52is that memory isn't a filing system.
00:07:54It's a reconstruction of what could have happened,
00:07:57and under normal circumstances,
00:07:59we do pretty well in remembering things.
00:08:02We might get a couple of details wrong, but generally speaking.
00:08:04The evidence suggests
00:08:08that we're really good at reconstructing what could have happened.
00:08:10That fades over time. But that's OK. As long as you're not making huge errors,
00:08:13you're doing fine.
00:08:19Anyone who can remember
00:08:20100% of what actually happened is actually a bit weird,
00:08:21because that's not something that we expect.
00:08:26And in fact,
00:08:29Russian neuropsychologist called Gloria had a patient
00:08:30called S who had this remarkable memory
00:08:34and so they could show him a blackboard with 100 random numbers written onto it.
00:08:38And 10 years later,
00:08:46he could reproduce
00:08:48that blackboard, all of the numbers where they were.
00:08:50Now that sounds cool. Actually, it's not
00:08:53because
00:08:55today is more important to you than yesterday,
00:08:57which is more important to you than last week.
00:09:00It's more important to you than a month ago.
00:09:03Forgetting
00:09:06and being able to know that your recent
00:09:08memories are important is actually a survival skill.
00:09:11If you can't tell today apart from last year, apart from 10 years ago,
00:09:14that how do you know what is important to you?
00:09:20So forgetting is actually really important,
00:09:22So don't worry if you forget things as
00:09:25long as you're not abnormally forgetting things,
00:09:28your memory is working fine
00:09:30
Cite this Lecture
APA style
Jansari, A. (2022, February 17). Memory – Disorders and Brain Damage - Reconstructive Memory [Video]. MASSOLIT. https://massolit.io/courses/memory-disorders-and-brain-damage
MLA style
Jansari, A. "Memory – Disorders and Brain Damage – Reconstructive Memory." MASSOLIT, uploaded by MASSOLIT, 17 Feb 2022, https://massolit.io/courses/memory-disorders-and-brain-damage