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False memory a dilemma for courts
By Robyn Williams on The Science Show
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Those people who can be hypnotised, can be very susceptible to suggestions. We've seen this in hypnosis shows. But for some, their brains treat the suggestion as a recalled memory. It becomes a false memory and the idea or recollection whilst false, is laid down as fact, as a new memory. This is a major problem for courts and juries determining the value of the memories of witnesses.
Duration: 12min 49sec
Broadcast: Sat 12 Aug 2017, 12:21pm
Peter Naish
Retired, with links now to the
Sackler Centre for Consciousness Science
Brighton UK
Robyn Williams: Memory, such a fickle faculty. Let's play a game and you'll see. This is Peter Naish, formerly at the Open University in the UK on stage at the British Festival of Science.
You were on stage giving a wonderful demonstration of the ways in which we can be deceived by memory, a list of names, a list of nouns that for us just in the audience seemed to have no distinct connections. Could you demonstrate what kind of thing that you were trying to show?
Peter Naish: Yes. Memories are changes in our synapses. So the brain is full of neurons, lots and lots of interconnections between them. And as the brain analyses incoming information, it lets the information pass from neuron to neuron, across the little junctions which we call synapses, and as it flows it changes how easily following information will flow. It beats a well-worn path as it goes through and the next lot can go more easily. And it's that sort of change which constitutes memory. And the thing is, a synapse itself is a simple bit of chemistry and biology; it doesn't know itself what changed it.
So what happens if you give someone a list of words, such as 'tired, drowsy, darkness, bed, dreaming', et cetera, lots of words like that? Well, they all go flowing through the brain, changing synapses here and there as they go, and we remember them. But all those words are linked and they are linked to the concept of sleep, although I didn't say 'sleep'. But because they are linked, many of the synapses are used in the same lot. So although we can distinguish the word 'sleep' from, say, 'bed', clearly if we can tell the difference our brain has recognised the difference, so there are different synapses involved, different circuits are activated. But because they are so closely associated in our heads, there are also an awful lot of synapses in common between them, the networks of neurons involved are closely related.
So if I say words like 'bed' and 'darkness' and 'night', then every time you hear one of those words it will somewhat activate the neurons associated with sleep. By the time I've hit your neurons with so many of those words, your sleep neurons have been given an awful lot of nudging. And if five minutes later after talking about all sorts of things I say, now, tell me which of these words you heard in the past, when I get to 'sleep' you say, oh yes, that's familiar. Well, yes and no. It's true it was nudged but I never said it. So it's a way of inducing a false memory.
Robyn Williams: So you can actually use that if you want to deceive people, by manipulating that, having an association that is close and makes someone think, yes, they have remembered that. Give me an example of the kind of memory that is more than a party piece, where it actually counts, it makes the difference, in legal terms perhaps.
Peter Naish: Yes, indeed. Well again, let me just precede it slightly by saying that what I've just been talking about all sounds very trivial and, as you put it, a party piece in a way. But interestingly it does tell us something about people's ability to remember accurately. Not everyone succumbs to the little trick I just told you. Some people get sucked in with every one, and others are pretty resistant. And the people who are not very resistant to the problem, they also tend to be people for whom more real-life type memories will come up with things that probably didn't happen. And this can be very dramatic.
There's a lady whose name is very much associated with this field, an American researcher called Elizabeth Loftus, and she tells a story, and I hope I shall get it right and not have too many false memories myself. But it goes something along these lines. It's a sad story. When she was a girl she lost her mother. I think it was in a drowning accident. And years later a relative I believe it was but not someone closely involved, said, 'Oh, of course it was you, Beth, who found your mother's body, wasn't it.' And she hadn't realised that because it had been years before. But she thought about it and it began to come back and she could picture it and recall what had happened. And so after that it came up in conversation with another relative who had been very much involved with the accident, and she said, 'And of course I found the body.' And he said, 'No you didn't, you weren't even there.' She, who works in this area, had had a false memory. It can happen to any of us.
Now, legally it becomes important and it's very often associated with going along for therapy, someone who is depressed or whatever it is and they go and get some therapy, and unfortunately quite a lot of therapists are under the impression that an awful lot of our problems are down to things that happened to us when we were kids. And there is some truth in that, that if you have a grotty upbringing it probably isn't going to improve your life chances, and you may be depressed and all sorts of things. But being depressed doesn't prove that you had a terrible upbringing, and it certainly doesn't prove that you were sexually abused. That is what a remarkable number of these therapists seem to assume.
So the person who has come to visit them says, no, no, I didn't have a bad upbringing really, very average like the rest of us, some ups and downs. Ah, but you don't remember any abuse? No. Ah, that's because it's a terrible thing and you've repressed it. Now, there's not all that much evidence that we do repress things. It's very hard to demonstrate in the laboratory, whereas, as I've just been describing, you could ever so easily make people remember words that weren't there. And these people, they are sometimes hypnotherapists, not just any old therapist, and in hypnosis, for people who are susceptible, it's very easy to visualise things remarkably vividly, things that never were. And so someone will start to picture because the therapist is saying, 'Take yourself back, just imagine, can't you see someone there, this man, didn't he come…who was it? A name will come into your head.' And the person starts to visualise it. This sounds remarkable. If you're listening to me saying this you'd think, oh, surely that doesn't happen. Yes, it does I'm afraid, it does happen. And the person starts to have their brain activated, almost they start to have a memory. Of course it's not a memory. But, as I said, synapses don't know what activated them, and in no time at all it has become functionally a memory.
Normally if I hypnotise someone I might start off taking them to a nice beach, and some will come back and say that was unbelievably realistic, I didn't want to come back, it was gorgeous. So do they go away then thinking they've had a holiday on a beach? No, they remember that they were doing hypnosis. But if the setting is 'we are going back to find a memory', then as these hazy images begin to emerge, they interpret it, oh yes, it's true, there is something there, and they don't think, oh, this is just a silly hypnotist making me imagine something, however vivid or not, they believe it is a memory being uncovered. And this is the effect.
And just as true abuse in childhood is very damaging, the results of this are enormously bad. I've met many cases where all the evidence shows beyond doubt that allegations can't be true, but the poor person making them, they are in a terrible state, as if they really have had their life ruined by abuse from childhood, and you get the impression that it's always been awful for them. Whereas in the truth, it's a problem they've acquired quite recently, and the belief in the problem has shattered them. And instead of the therapy making them the better, they really seriously need some therapy now. And the problem then is that it will probably go to court, some innocent person is going to be accused and we now have another dilemma.
So what happens in court? You have someone whom you can show is hypnotically susceptible, they easily dissociate, the term used for zoning out and not having your feet firmly in the here and now, these sorts of people are prone to having false memories. And so if we can discover these characteristics in court, the defence will be, oh, look at this person, it's bound to be a false memory. But we also have to remember that the reason they have those characteristics may be, not inevitably but it may be because what they are alleging did take place. So it's a horrible dilemma for the courts.
Robyn Williams: Looking at something that's slightly more every-day, and that is people who are slightly older, having memories, tell their favourite stories again and again, and each time there may be a slight variation, we add a bit, part of the story. And we refresh that memory. And the idea is if you look at autobiographies like Graham Chapman from Monty Python, Autobiography of a Liar, or even Clive James, Unreliable Memoirs. Well, there is an assumption that there is something about the memory that is slightly iffy. Isn't it interesting that that's the kind of thing that happens with our own personal memories as well.
Peter Naish: Absolutely, yes. When we remember, we are reactivating the bits of brain that were active originally when the event first took place. But as we try and trace those footprints, as I described them, the beaten path from before, we don't necessarily find all the elements, and things are all linked together. So you are pulling related things that have become associated in your head and so on. So as you reconstruct your memory (and they are not neatly filed-away events, they are reconstructions every time as you try to find those paths), it's ever so likely that you will lose some elements, they won't come into the story this time around, and you will gather in some others that seem perfectly plausible and you are convinced they were part of it but they happen not to be. And it's not just that you've made a mistake then, but you've just activated those neurons. So what happens? They become the new memory. And over time the memory just morphs and it becomes what it must have been like, what it jolly well ought to have been like, but not necessarily anything particularly like what really happened.
Robyn Williams: Peter Naish, now attached to the University of Sussex. And you realise that each case is of course different, and memory can be tested in many ways. Professor Dagg has an opinion:
Fred Dagg: Yeah, g'day. I'd like to have a word or two with you about the Socratic paradox, which, without being too technical about it, is a paradox worked out by the late Socrates in order to explain some of the pitfalls involved in explaining things.
The argument says in essence that you can't learn things you don't already know, and given the widely accepted view that there is some difficulty to be encountered in trying to learn something you do already know, I'm afraid it's beginning to look as if the whole business of learning is largely overrated and probably should be left alone.
I personally have always held this to be more or less self-evident, although unfortunately my reasoning turns out to be a good deal less Platonic that I had hoped. Socrates argued that if you don't know something you probably wouldn't recognise the knowledge if it popped up in your porridge. And if you did recognise it then in some sense you must already have had the knowledge beforehand. And that, therefore, learning is merely a process whereby we recollect knowledge which is already in us.
This, of course, touches on the Fred Dagg Theory of the Human Memory, and even though Socrates doesn't, so far as I know, have any real right of reply in the matter anymore, there are just one or two points I'd like to clear up.
Firstly, if the knowledge is in there anyway, at what stage was it put there and whose job is it to go about the place feeding knowledge in through people's ears before the memory takes over and renders the whole thing academic? As a matter of fact, I knew a bloke once who thought we were all born with a certain number of words in us and when we talked them out, we died, which impressed me as being fundamentally sound until I found out that he thought 'Portia Faces Life' was the story of a woman named Portia Face.
This knowledge represented the recollection of something I don't think Socrates has made enough allowance for, and that is that lack of knowledge or the knowledge of things that aren't quite right can be recalled just as easily and in some cases of course more easily than good solid everyday stuff like coming in out of the rain.
It's also of course possible to forget things and then forget that you've forgotten them. And then if you can recall the fact that you've forgotten something, does this necessarily qualify as knowledge? As a matter of fact I'll try and get back to you on this one. I'm a little bit confused at the moment and it's nearly time for my tablet.
Robyn Williams: Keep taking them, Fred.
Presenter Robyn Williams
Producer David Fisher
external link Sackler Centre for Consciousness Science
external link Falsifying memories – The Guardian 17th August 2013
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