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Hi, everyone. |
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Do you hear me? |
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Do you hear me? |
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Okay. |
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Hi, everyone. |
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If you can take your seats and settle down, I |
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can. |
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Make some concessions. |
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Okay. |
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So today we're going to talk about technologies to treat |
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neuro disorders. |
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And this is kind of a follow up of this |
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week's series of lectures, which is about kind of methods |
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and techniques that are used for neuroscience in general brain |
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and behaviour. |
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So just a bit about myself. |
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I actually started off as an engineer, which is probably |
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why they picked me to take this lecture so I |
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can talk a bit more details about that stuff, but |
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you won't be examined on that anyway, so. |
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Okay, so how can we use technology to treat neuro |
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disorders? |
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There's basically three main ways in which we can try |
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and get at this kind of three broad categories. |
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One is to use it to read from neurones. |
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So this is something where you can use prosthetic devices |
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that are controlled by interpreting neural activity or something like |
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that. |
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The second is to actually write to neurones. |
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This is something where we try and look at something |
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that's happening in the external world and try and write |
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into right to the subject's brain directly. |
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And the third is to actually just use it to |
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control abnormal activity. |
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So this is something where we have something like a |
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pacemaker to control abnormal brain activity. |
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So I'll cover these three during this lecture, mainly focusing |
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on the first two. |
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So in terms of the first one, you might have. |
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So if you're trying to read from neurones, there's three |
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kind of stages to it in general. |
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The first thing is we need to be able to |
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observe neural activity. |
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So what's happening in the brain? |
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You want to try and read that first, interpret this |
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activity, to try to understand, well, what's happened, what's the |
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kind of process that the individual or the subject is |
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trying to do? |
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And finally, then control or manipulate an external device. |
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So in general, the last bit, which is about controlling |
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and manipulating external devices, is more of an engineering problem. |
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So we're not going to get into that. |
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The main focus is going to be on observing neural |
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activity, which is something where you need a recording device |
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and this is kind of using neuroscience to try and |
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develop these ones. |
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And then we need to understand this by using some |
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kind of computational approaches and in combination with an understanding |
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of what the brain is doing. |
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Okay. |
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So what type of activity can actually be used? |
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I mean, when I talk about observing neural activity. |
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So this is something you might have covered, Sam Solomon |
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would have covered in the previous lecture. |
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The first thing is something like recording spiking activity, which |
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is the firing of action potentials across a population of |
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neurones. |
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This could be either by implanting electrodes into the brain |
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or reading from peripheral nerves in around the body. |
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Another technique that could be used is ephemeral, kind of. |
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Briefly touch upon that. |
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And finally, something that's broader at a larger scale is |
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using things like brain oscillations or EEG. |
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So electro echo or electro cortical grabs, which is something |
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that Sam would have covered, but it's something where we've |
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kind of got either an external device or something like |
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a. |
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Cat. |
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That's recording oscillations still. |
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How do we then use it to how do we |
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interpret the activity and control a device? |
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So a third of it, the broadest device, which is |
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the EEG, it's a non-invasive technique. |
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So what we record is neural oscillations. |
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These are brainwaves or from large regions of the brain. |
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So as you can see this, it's just a. |
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Cat which. |
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Is looking at different. |
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There's multiple electrons placed across the across the head. |
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And you just basically looking at the electrical activity around |
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that, around each of those points and using that, you |
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can slightly localise what's happening in the brain. |
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So what we can actually interpret is quite coarse because |
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it's kind of recording from large regions of the brain. |
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It's not something we can get very specific information about, |
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but kind of contrasting activities between different regions is something |
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like left versus right side of the head or the |
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front in the back. |
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And so given that it's very coarse measurement, what we |
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can actually do is get very coarse control over things. |
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So you can get something like you can get yes, |
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nuances or something where you can move forward or move |
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backwards and so on. |
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So that is going to show an example of this |
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in action. |
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So this lecture is going to have a lot of |
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videos because I think the best way to actually see |
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what's happening, it's quite dramatic. |
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But something. |
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Like 50 different. |
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Countries in the Middle East. |
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Okay. |
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So as you can see, this subject is able to |
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control the wheelchair based on this new act, based on |
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this age group that is thinking about something or based |
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on what he's thinking or what is in this case, |
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he was moving his head down as well. |
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Based on what he's doing, he's able to control the |
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wheelchair. |
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But know that, you know, this is quite something complex |
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happening in terms of like going up the stairs and |
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so on. |
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Is this probably not being controlled by the by the |
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device? |
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Because, as I said, it's quite coarse measurement. |
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So what he's able to do is something like move |
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up and down. |
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They're just moving the wheelchair up and down or maybe |
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move the wheelchair forwards and backwards. |
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So there's like some amount of control that he can |
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have, but that's about it. |
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There's another this is it's a link to a video |
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which is probably going to show as an idea. |
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I know it's for you to watch later. |
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It's I just put the link up there, but it's |
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got quite a detailed explanation. |
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If you're interested of how a group of students from |
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a school come together to actually build a wheelchair that's |
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based on EEG. |
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So it's a group of like I think ten students |
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and they split the problem up into the various aspects. |
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So one team is doing kind of the EEG aspect |
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in the data collection. |
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One team is each there's like multiple teams doing these |
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things. |
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And finally they're able to control a wheelchair based on |
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just the EEG. |
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Okay. |
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So one other thing is, like, this is quite a |
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cost measurement. |
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So in some cases what you have is what you |
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can do is rather than use, try and interpret what |
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exactly the brain is saying. |
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So, you know, if you're trying to, you know, grab |
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something and and do something, it might be quite hard |
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to interpret that fine scaled action using this such a |
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coarse measurement. |
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So what you can do is do some. |
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Hacks. |
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And this is an example of that. |
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To demonstrate how this technology works. |
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Well, you get some studying nonverbal communication you can do. |
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A lot of people are learning. |
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What. |
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It's like to get a lot of different types of |
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responses, like the specific one picked up by the victim |
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or. |
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And nobody reported. |
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Well, I that. |
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Frequency of no. |
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Except for, you know, the computer interpret the signal to |
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give the correction some response. |
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So the reason I picked this video is something where |
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what they've used is kind of a hack of trying |
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to control this, trying to get some answers. |
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So they put this flashing light one a 12 hertz, |
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one and 13 hertz. |
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And it's just when you look at a flashing light, |
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you're visual cortex usually lights up, tries to go between |
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certain frequencies. |
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It follows what's happening with the lights. |
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If it's if it's oscillating, if the light is oscillating, |
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the visual cortex is going to oscillate in in sync |
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with that. |
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And so they're able to just detect what the oscillation |
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frequency is, and they're using that as kind of a |
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hack to try and look at like, does a subject |
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want to go left or right? |
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So it's kind of a binary answer or. |
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It's a binary answer and they're able, but it's quite |
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effective at trying to get this subject who is immobile |
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to. |
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You can read their brain in a sentence, as I |
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said multiple times. |
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Now the limitation is it's a very close spatial resolution. |
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It's the amount of information you can get is quite |
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limited. |
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So we can now move to another non-invasive technique, which |
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is MRI. |
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And you might have heard about this before. |
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It's something that records blood oxygen levels in the brain. |
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And we can interpret this based on the activation levels |
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from different regions of the brain. |
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And this is kind of going from the very coarse |
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resolution of a few of multiple millimetres in the EEG |
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to something more at a millimetre scale or this quite |
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low temperature resolution. |
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So you need like hundreds of milliseconds to actually interpret |
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the activity. |
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So it's a really cool demonstration that was there a |
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few years ago. |
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It has actually gotten a lot better in the recent |
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years, but here's an example of it. |
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So let me just explain what this is showing. |
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So this is the movie that is presented to the |
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A subject. |
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This is a variation of that which is just they're |
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just looking at what are the edges in that image |
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And this is what is decoded. |
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So you look at the brain activity in the scanner |
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and based on the activity of the brain, they actually |
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just trying to try and decode or guess which movie |
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was presented based on the brain activity. |
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So this is. |
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So. |
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Yeah. |
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What's happening there. |
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But in. |
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General. |
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We have to do things. |
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Okay. |
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Anyway, in general, what you would see is that as |
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in this example here, you don't quite get a perfect |
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match of what the subject is seeing, but you see |
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some approximation of it. |
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So it's it's it's decent, but it's it's, it's just |
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an approximation. |
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Again, here edges are slightly better in the movie. |
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If you see the movie, it's usually. |
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Okay, maybe with back elements. |
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If you see the movie, you can see that it |
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doesn't quite always get it right. |
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There's there's a lot of variations in general. |
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So one of the major limitations of ephemera is the |
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fact that it's a huge device. |
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So this is like it takes usually it takes a |
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whole room and another room to have like a cooling |
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system and so on. |
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So it's something that's not really practical to use as |
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a day to day device to kind of help treat |
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or to use as a neural interface. |
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I really hope the following videos work, but so another |
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option is to record from periphery nerves. |
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So this is where it's cool. |
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So far we've been talking about recording from the central |
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nervous system, so just the brain as such. |
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But there's a lot of nerves in the in the |
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body and sometimes maybe it's more effective or easier to |
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actually get to the periphery. |
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There's a few advantages, advantages to this. |
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The first thing is you don't need to get to |
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the skull where, you know, implanting anything or interpreting activity |
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through the skull is actually quite a big challenge. |
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So you can get across that by recording in the |
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periphery. |
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And this is I really hope it works an example. |
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Okay. |
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This is an example. |
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So this particular subject has two kinds of prostheses. |
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The prosthesis is either controlled by a electrode that is |
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placed on the surface of his arm and shoulder, or |
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there's a there's a second option, which is that they |
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actually implant the electrode into the arm and the aid |
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record from within the neurone as such. |
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So the idea this demonstration is basically showing how by |
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implanting the electrodes into the body, you're able to get |
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better control because there's a little bit more information. |
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So as you try to record from outside, the information |
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is a bit more noisy in terms of as a |
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recording technique. |
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So this is an example of him trying to control |
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holding an egg. |
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You can see that with the external electrodes he is |
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able to control it, but he's not able to control |
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every aspect of it. |
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And that's something where you can imagine the number of |
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things that are needed. |
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So in general, I was talking to you about like. |
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Yes, nuances in the. |
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We can just watch this again. |
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So the surface electrodes. |
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He's not able to really control it. |
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Hopefully. |
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Implanted electrodes and you can see that it's a lot |
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better. |
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The fact that he's able to do either just control |
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the arm is actually quite amazing compared to what we |
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used to have, where you just have like a phantom |
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thing which is just attached to the body and you |
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kind of passively control it. |
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So in this case, this device is actually integrated into |
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the kind of the periphery nervous system where the subject |
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is able to control kind of the action of light, |
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how much is moving, grabbing something and moving it in |
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different directions. |
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So going back a little bit to what I was |
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saying before with the EEG, it's kind of, yes, the |
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onesies or maybe for four ounces. |
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Here again, you've got your recording from various neurones and |
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you're trying to get a few different quick answers. |
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In the case of the prosthetic arm, it's how much |
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you want to press. |
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How how do you want to grab something? |
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So if it was just like grab and release, that's |
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probably something you can get from a surface electrodes. |
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The more information you have, the more accuracy you can |
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get at various things. |
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So that's the general idea of the difference between the |
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surface electrode and the implanted electrode. |
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And this kind of holds across various devices. |
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So the more information you have, the more accuracy you |
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can have in controlling various things. |
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So this is just an example of a periphery system. |
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And here we're recording the neural activity of individual or |
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sorry, that was the periphery neurones. |
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And I guess one of the limitations here is that. |
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But in this particular case, it was pretty clear that |
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the prosthetic arm was something that just the subject needed. |
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But if you want to try and control, let's say, |
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like a wheelchair or something, maybe you don't have access |
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to these with these nerves. |
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A lot of these the videos I'm going to show |
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you next are in paraplegic subjects who really can't actually |
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control any of their nerves, make them. |
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So in that case, you need to then go up |
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and record from the brain directly. |
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And in this case, what you're able to record is |
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actually a neural activity from an individual or a collection |
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of neurones that are in the brain. |
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And given that you're actually recording from within the brain, |
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you can now record from a large number of neurones |
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and you can record spiking activity at a higher temporal |
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and spatial resolution. |
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So I just show an example of things that showed |
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some of this in general. |
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So this is a braingate system which has been deployed |
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in human subjects. |
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This is an example of what the electrode looks like. |
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So there's like a ten by ten grid of electrodes. |
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It's about this big you can see in a human |
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now, and this one is implanted usually within the brains |
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around the motor cortex or this embedded sensory cortex of |
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some subjects. |
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So just to show you. |
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This is why we call it. |
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I think I'm showing you a bit of this video |
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before I like to show this as an example, where |
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this patient who's. |
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Out. |
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Here is abled is controlling an arm using one of |
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these systems. |
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And this is an example of her trying to drink |
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coffee, have a sip of coffee from this. |
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From above. |
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By controlling the robotic. |
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Arm. |
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Then when you watch the video, you can make note |
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of the fact that it's around 140 at a time. |
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Samba was at 140 with in the video. |
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You can have a look at this later. |
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But it's something where it's quite moving because it's the |
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first time she was able to actually actually control something |
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by herself and then have a sip of of coffee |
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from there. |
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One of the things to note and this is like, |
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as I mentioned, this is a huge engineering feat to |
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get like an arm, a robotic arm to do something |
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like this. |
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So a lot of these technologies are also based on |
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some very cool engineering that goes into the backflip. |
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I'm not going to show, if I can, a newer |
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version of this. |
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Oh. |
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Okay. |
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So in this case, this subject again, it's got this |
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BrainGate device and very able to browse the Internet. |
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And usually what that is, is like you've got the |
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cursor here bottom, it's the other video. |
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So what this subject is able to do is actually |
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control the cursor on the monitor. |
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Then again, by controlling the cursor on the monitor, they're |
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able to type in an email. |
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Okay, So this is kind of where this is at. |
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|
They're doing a lot of human tests. |
|
|
|
But as you can see, it's ethically it's basically something |
|
|
|
that you would use for paraplegic patients where they're unable |
|
|
|
to use. |
|
|
|
There's very few other options for them to actually try |
|
|
|
and interact with the world. |
|
|
|
So I'm finally going to show you something that's beginning |
|
|
|
Looking to the future. |
|
|
|
This is a demonstration by model group. |
|
|
|
Sorry, let me shut my female. |
|
|
|
Yeah. |
|
|
|
This is a demonstration from Elon Musk's team that are. |
|
|
|
So just to give you an idea of what they've |
|
|
|
come up with is as he does, he started a |
|
|
|
new company that is trying to revolutionise neuroscience. |
|
|
|
But anyways it's debateable. |
|
|
|
But one thing that they've definitely been quite successful at |
|
|
|
is developing some of these devices. |
|
|
|
So what you actually see here is a robotic device |
|
|
|
that's used to implant electrodes into the brain. |
|
|
|
And the reason for that is they've come up with |
|
|
|
this new electrode design, which is quite like what you |
|
|
|
saw before in this slide was this kind of device. |
|
|
|
Now, this is this, as you can see, the rigid |
|
|
|
structure that is placed on the surface of the brain. |
|
|
|
Neuralink instead has come up with a new version of |
|
|
|
it, of a new design where you've got independently movable |
|
|
|
electrodes. |
|
|
|
This is something that we usually use in the lab, |
|
|
|
but more but not as many simultaneous people. |
|
|
|
So they actually put in like about a thousand electrodes |
|
|
|
in to try and target individually different brain regions. |
|
|
|
And that then goes into this device, which is which |
|
|
|
is really tiny. |
|
|
|
And that's actually one of the innovations of the company. |
|
|
|
It's quite impressive. |
|
|
|
It's it's about the size of a coin, maybe like |
|
|
|
a pound coin or something like that. |
|
|
|
And so it's also quite thin and can it is |
|
|
|
within the thickness of the skull. |
|
|
|
So for a human skull and in this case they |
|
|
|
demonstrated on pigs. |
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|
|
And so it's also within the thickness of a pig's |
|
|
|
skull so they can just implant it. |
|
|
|
So it's flush with the the surface of the of |
|
|
|
the skull. |
|
|
|
And another innovation that they came up with is when |
|
|
|
you look at the BrainGate videos, you see that there's |
|
|
|
this big cord coming out, there's this big device attached |
|
|
|
to the head, and then there's a big wire coming |
|
|
|
out instead. |
|
|
|
The other innovation that the companies come up with is |
|
|
|
that they've made everything kind of via Bluetooth. |
|
|
|
So it's wireless and so it's just on the skull. |
|
|
|
You can actually have. |
|
|
|
A go back or. |
|
|
|
You can have like the skin cover up that area |
|
|
|
once, once everything is done and then everything's going over |
|
|
|
wirelessly. |
|
|
|
So this is a demonstration of this is. |
|
|
|
Actually, this animal actually has. |
|
|
|
This animal actually has an electrode implanted in it. |
|
|
|
You just don't see any any sign of it. |
|
|
|
It's it's moving around really healthy. |
|
|
|
And so now this is where they're going to move |
|
|
|
it into an area where it can actually get to |
|
|
|
wireless signals. |
|
|
|
Okay. |
|
|
|
So the recording from like thousands of neurones, then each |
|
|
|
of these each of these rows here represents the action, |
|
|
|
an action potential firing from an individual neurone. |
|
|
|
You can see they're able to actually like while the |
|
|
|
pig is moving around, you can see looks is. |
|
|
|
Happening in real quick signals. |
|
|
|
So literally neurones that are out over here and put |
|
|
|
them on a virus which is affected here. |
|
|
|
Okay. |
|
|
|
So I was just going to show you another towards |
|
|
|
the end of this video, they're looking at like how |
|
|
|
they can interpret the activity. |
|
|
|
It's a while that hopefully loads up. |
|
|
|
So it's a bit of a weird system. |
|
|
|
So one of the things that Neuralink was it's quite |
|
|
|
controversial among neuroscientists because they kind of said it is |
|
|
|
this big advance. |
|
|
|
But in terms of to the neuroscience end of things, |
|
|
|
there's actually like a lot of what they've been talking |
|
|
|
about is something that we've known, for example, the BrainGate |
|
|
|
system, it's been there for over ten years now and |
|
|
|
it's something where you can actually decode activity in control |
|
|
|
devices. |
|
|
|
Okay. |
|
|
|
So this is an example. |
|
|
|
Of a digital activity. |
|
|
|
An example of a pig running on a walking and |
|
|
|
a treadmill. |
|
|
|
And by recording from the motor areas of the brain, |
|
|
|
they're able to actually decode the positions. |
|
|
|
I've been reading they're going to look like on that |
|
|
|
record. |
|
|
|
And we think that the photographs and records submitted. |
|
|
|
Okay. |
|
|
|
So just this that's just trying to predict various points |
|
|
|
on the limbs of the limb of the animal. |
|
|
|
And you can see that basically the actual limb position |
|
|
|
versus the predicted limb position, it's quite accurately decoded. |
|
|
|
So the mission statement of the company is kind of |
|
|
|
weird. |
|
|
|
They want to have everyone have access to these things, |
|
|
|
but that's kind of scary to me to enhance your |
|
|
|
brain. |
|
|
|
It's scary because you need to put something in the |
|
|
|
brain and make a big hole in your skull. |
|
|
|
So now they've kind of toned it down. |
|
|
|
They're talking about, Oh, we're going to use it for |
|
|
|
paraplegic patients. |
|
|
|
So they're getting human they're they're kind of getting to |
|
|
|
FDA. |
|
|
|
I think they've got FDA approval to test in paraplegic |
|
|
|
subjects who similar to the BrainGate device. |
|
|
|
And so I think that it's pretty cool for that. |
|
|
|
I just don't know how they're going to. |
|
|
|
Make. |
|
|
|
Money off of it like they want to. |
|
|
|
But it's a pretty cool tech and lot of innovations |
|
|
|
on the engineering end of it in terms of being |
|
|
|
able to record neural activity. |
|
|
|
Hopefully they bring it back, they send it back to |
|
|
|
science. |
|
|
|
Right now, everything's closed. |
|
|
|
We don't have access to any of these technologies. |
|
|
|
Okay. |
|
|
|
So the limitations, as you can expect, it's highly invasive. |
|
|
|
So again, you need to put these electrodes into the |
|
|
|
brain so it's not something that you can do that |
|
|
|
easily. |
|
|
|
And like I said in the beginning of the Neuralink |
|
|
|
thing, you've got this huge robot that they've actually designed |
|
|
|
and that's part of their part of their innovation that |
|
|
|
they needed to develop this robot to be able to |
|
|
|
implant these electrodes. |
|
|
|
Okay. |
|
|
|
So I've just reviewed a few different ways in which |
|
|
|
you can read neural activity. |
|
|
|
I'm going to skip ahead now to the second part |
|
|
|
of the talk, which is about writing to neurones. |
|
|
|
And this is something about transmitting information that a subject |
|
|
|
cannot access. |
|
|
|
And for this, we kind of. |
|
|
|
Rather than go this way, we have to go the |
|
|
|
opposite way. |
|
|
|
Who would observe or monitor the external events, interpret this |
|
|
|
information, and then edit neural activity to send it back |
|
|
|
to the brain. |
|
|
|
So how can we edit or manipulate activities? |
|
|
|
It is generally, there's a few different ways you can |
|
|
|
either electrically stimulate neurones. |
|
|
|
This is the most common method and this is something |
|
|
|
I've been talking about mostly. |
|
|
|
And then there's also a possibility of using magnetic stimulation. |
|
|
|
It's much more cause they're not that well understood. |
|
|
|
It's a very commonly used. |
|
|
|
And then more recently, there's something like optical stimulation, where |
|
|
|
you use some genetic approaches to make neurones fire when |
|
|
|
you shine light at them. |
|
|
|
Chemical stimulation is possible, but it's very hard to have |
|
|
|
precision in terms of controlling that. |
|
|
|
So I'm going to jump straight into cochlear implants, which |
|
|
|
is probably the most impressive and most commonly used brain |
|
|
|
machine interface. |
|
|
|
So this is the issue is that there's loss of |
|
|
|
hearing due to some issues in the early stages of |
|
|
|
auditory processing and by early stages that's around this region |
|
|
|
here before the auditory nerve, there's there's issues that are |
|
|
|
happening before the auditory nerve. |
|
|
|
So one of the advantages and one of the reasons |
|
|
|
why this has been such a success story is because |
|
|
|
of the structure of the ear and the auditory nerve, |
|
|
|
and that's specifically the cochlear of the. |
|
|
|
Of. |
|
|
|
The cochlear system. |
|
|
|
So this is an example. |
|
|
|
This is kind of an illustration of what the cochlear |
|
|
|
is, is is this this bit here it's the coined |
|
|
|
surface. |
|
|
|
And at different parts of the cochlear, the auditory nerves |
|
|
|
kind of go along different parts of the cochlear. |
|
|
|
And just based on sound frequencies, the way sound travels |
|
|
|
through the surface, it attenuates different frequencies at different points. |
|
|
|
So it's a beautiful design of evolution and it's the |
|
|
|
way it takes advantage. |
|
|
|
So you've got the highest frequencies at the outermost point |
|
|
|
of this. |
|
|
|
So this is around 20 kilohertz and you go down |
|
|
|
up until like a 200 hertz region that's at the |
|
|
|
apex. |
|
|
|
So this is kind of the the structure of the |
|
|
|
human cochlear. |
|
|
|
I illustrated here where you've got like the different medium |
|
|
|
frequency coming into the middle and then the lowest frequency |
|
|
|
waves reaching all the way to the apex so that |
|
|
|
the auditory nerves kind of in a way, different regions |
|
|
|
of this. |
|
|
|
And so in a sense, what this the advantage of |
|
|
|
this is this has brought all of auditory processing, which |
|
|
|
is quite a complicated process into a single one dimensional |
|
|
|
axis here. |
|
|
|
So this is one long. |
|
|
|
So if you stretch out this coil, it's basically one |
|
|
|
thing, one long stretch of tissue. |
|
|
|
And the advantage now is that if you estimate a |
|
|
|
different point of this tissue, they're able to generate different |
|
|
|
perceptions of different sounds. |
|
|
|
And that's what is taken advantage by the cochlear devices. |
|
|
|
They have a device that goes all along this. |
|
|
|
Coil and. |
|
|
|
It can stimulate different portions of this. |
|
|
|
So this is what a cochlear system would look like. |
|
|
|
So on the external side of things, you've got a |
|
|
|
recording device that this is something that's recording sounds from |
|
|
|
the outside and it's kind of doing some amount of |
|
|
|
processing of those sounds and then transmitting this to a |
|
|
|
transmitter that's on the surface of the of the skull. |
|
|
|
And then internally you've got a receiving device that's there |
|
|
|
just just on the inside of that. |
|
|
|
And then you've got another kind of stimulator or kind |
|
|
|
of a processor there and then goes into this coil |
|
|
|
device that going all along the cochlear. |
|
|
|
And you can see there's these different bits here. |
|
|
|
These are like the electrode sites and this is the |
|
|
|
electrodes that are able to kind of the cross currents |
|
|
|
to stimulate different portions of the of the cochlea. |
|
|
|
And by stimulating different parts of the cochlea, they stimulate |
|
|
|
different sound levels and different sounds. |
|
|
|
And so by having like a nice simple linear transformation |
|
|
|
and then because it's an electric signal, it's quite fast. |
|
|
|
So you can have, you know, as I'm speaking, all |
|
|
|
the different frequencies of sound that I'm conveying, are able |
|
|
|
to, you can actually process that and get it to |
|
|
|
all the different points at a very fast times. |
|
|
|
So that's the kind of advantage. |
|
|
|
And I'm just going to show you this video here, |
|
|
|
which you can watch later. |
|
|
|
It's the nice description of a doctor describing how a |
|
|
|
cochlear works. |
|
|
|
But what I find really moving is this is this |
|
|
|
is a documentary. |
|
|
|
I would highly recommend watching all of it. |
|
|
|
At some point, I'm just going to. |
|
|
|
The complete 100% sound science. |
|
|
|
What can happen? |
|
|
|
I hear what I'm saying and how it sounds because |
|
|
|
I know it sounds different. |
|
|
|
But this I find that my voice is back to |
|
|
|
normal. |
|
|
|
Hi. |
|
|
|
Makes me 70% or so. |
|
|
|
So I usually show a longer plate of the clip. |
|
|
|
I just realise it's too late. |
|
|
|
But if you noticed that her voice was changing, she |
|
|
|
took out the implant. |
|
|
|
And actually, if you saw it from earlier, it progressively |
|
|
|
gets worse and worse as she's speaking. |
|
|
|
And you can also see her getting not very confident |
|
|
|
and as she says, insecure. |
|
|
|
And then as soon as she puts it on, the |
|
|
|
voice changes completely. |
|
|
|
And that's just the fact that she gets this feedback. |
|
|
|
Rather than putting our accessibility first. |
|
|
|
We want to get people who. |
|
|
|
Actually. |
|
|
|
Complete 100%. |
|
|
|
I'll go back a little bit because. |
|
|
|
I think so. |
|
|
|
What kind of stuff? |
|
|
|
I take it off, so I keep it off for |
|
|
|
the more exciting stuff, seems to become more convoluted and |
|
|
|
becomes more difficult to think about what they ought to |
|
|
|
be something. |
|
|
|
You know what I'm saying? |
|
|
|
Because I don't think it's a matter of speaking to |
|
|
|
the cow when I pick my husband so I can |
|
|
|
hear people. |
|
|
|
So I'm not even being a complete 100%. |
|
|
|
So what's possible? |
|
|
|
So I'm a little insecure about what I'm saying because |
|
|
|
I know it sounds different. |
|
|
|
But the 70 seconds and trying to keep things back |
|
|
|
to normal, I think means. |
|
|
|
I think that one might have been clearer as you |
|
|
|
saw the progression as well as how the design changed. |
|
|
|
So you can see it's actually a really for me, |
|
|
|
this is probably the biggest success stories of a neural |
|
|
|
interface that you. |
|
|
|
So you need to have something. |
|
|
|
The deftness where it works is something where the auditory |
|
|
|
nerve is intact and then like further on, it's able |
|
|
|
to it's able to process. |
|
|
|
And most of the hearing disabilities come from kind of |
|
|
|
early hearing, early stage hearing loss. |
|
|
|
So it is quite. |
|
|
|
That's why it's so commonly used, because it's kind of |
|
|
|
an early stage thing. |
|
|
|
So moving on from hearing actually, the next one would |
|
|
|
be, well, can we actually then take this into the |
|
|
|
eye, which is the other sense. |
|
|
|
Organ or. |
|
|
|
Something? |
|
|
|
So. |
|
|
|
So this would be something where if you have loss |
|
|
|
of vision at the level of the eyes. |
|
|
|
So again, like there's quite a few issues that do |
|
|
|
happen at the eye. |
|
|
|
I think vision has a broader range of issues happening |
|
|
|
in general. |
|
|
|
So as I mentioned, the the auditory system had this |
|
|
|
nice coiled structure that actually just boiled down to like |
|
|
|
a single thing. |
|
|
|
So when it comes to the eye, it becomes you've |
|
|
|
just added another dimension. |
|
|
|
Now things are in 2D, you've got like a 2D |
|
|
|
scene that you have. |
|
|
|
You could argue that that's there in the auditory system |
|
|
|
as well, but at least the amount of information you |
|
|
|
can get across with this one dimensional structure is sufficient |
|
|
|
for a subject to get a good perception of things. |
|
|
|
But with vision, it tends to be a lot harder |
|
|
|
because you've got you've got a lot more detail in |
|
|
|
structure and we're kind of used to seeing this amount |
|
|
|
of detail. |
|
|
|
So it becomes harder to and again, you've moved from |
|
|
|
a one dimensional structure. |
|
|
|
Now you've gone to a flat surface, which is the |
|
|
|
retina here, and you've got like a two dimensional structure. |
|
|
|
So the general idea of how an implant like this |
|
|
|
would work is that you have a camera that's, you |
|
|
|
know, subject with bathroom glasses, with a camera attached on |
|
|
|
them. |
|
|
|
They've got some kind of processing that's happening on an |
|
|
|
external unit that then gets transmitted into the device that's |
|
|
|
within the eye, and then that goes onto a kind |
|
|
|
of a chip that's then this retinal implant that's then |
|
|
|
stimulating either electrically or optically. |
|
|
|
It's the surface of the retina. |
|
|
|
Now, one of the issues with this is that actually |
|
|
|
there's a lot of different receptors in the eye. |
|
|
|
So it's not just about, you know, on off in |
|
|
|
one retina region, you have colours, you have edges, you |
|
|
|
have lots of different things. |
|
|
|
So what you would get is kind of flashes of |
|
|
|
light at different parts of the of your visual field. |
|
|
|
So it's not quite detail information that you would, that |
|
|
|
we would usually do so wouldn't be able to see |
|
|
|
faces or recognise faces but kind of a flash of |
|
|
|
image. |
|
|
|
So in general I think the target of this is |
|
|
|
to help subjects get some amount of information which would |
|
|
|
help them with their day to day lives through something |
|
|
|
like if you're a child across the road and there's |
|
|
|
a car coming, you could flashlight light towards which part |
|
|
|
where the car is coming or something like that. |
|
|
|
But it's not something where you would be able to |
|
|
|
get a subject. |
|
|
|
You read a book or something as detailed as that. |
|
|
|
So it it is a much more challenging area, are |
|
|
|
trying to get a device into the eye. |
|
|
|
There's been a lot of attempts at it, but it's |
|
|
|
been quite challenging at the same time. |
|
|
|
There's also been some issues of the levity of the |
|
|
|
implant and how effective they can be and the health |
|
|
|
of the surrounding tissue, because it's quite a different tissue |
|
|
|
in the eyes. |
|
|
|
One other thing. |
|
|
|
Yeah, I'll move. |
|
|
|
On to another way of writing to nuance. |
|
|
|
I'm not going to go into the details of this, |
|
|
|
but it's something that would be useful for you all |
|
|
|
to be aware of. |
|
|
|
So this is something called optogenetic manipulation of the nerve |
|
|
|
cell activity. |
|
|
|
And this is where. |
|
|
|
So I think last week you've got you had a |
|
|
|
lecture on neurotransmitters and how things are going between the |
|
|
|
membrane of a neurone. |
|
|
|
So this is an example of this, the internal area |
|
|
|
of the brain of a neurone and the outside. |
|
|
|
And there's various proteins that are expressed on the membrane |
|
|
|
of a neurone. |
|
|
|
So what this was an innovation that was there a |
|
|
|
few years ago where they implanted, where they expressed a |
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protein that's the ion transmitter. |
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That was when you shine a light on it. |
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This is actually a Dobson, which is something like what's |
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in the eye when you shine a light on it. |
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It then opens this channel and lets various ions through. |
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And using this technique you're able to get a neurone |
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to get excited or to get inhibited. |
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So this is an example where this is kind of |
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an illustration. |
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You've got these blue, they're shining a blue light at |
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different points in time, and every time there's a blue |
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light you get, you get an action potential. |
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And then if you use the other kind of hyper |
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polarising protein you can get, like when you apply a |
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different kind of the colour of light, you can even |
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get suppression. |
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Of. |
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Firing in neurones. |
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So this is a general strategy where you can use |
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the light to activate neurones either in the brain. |
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And actually this is something that is. |
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Being tried out even in the eye. |
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So trying to rather than putting in electrical activity, which |
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is kind of which damages the tissue as well. |
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They're trying to put in a a chip that then |
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just transmits a light pattern onto it. |
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I'm so not going. |
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To go into that, but I'm just going to move |
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on to the next part, which is about controlling abnormal |
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activity in the brain. |
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And this is where. |
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So in general, when you have a normal activity, the |
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most common method is to try and use prescription drugs |
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to control abnormal activity or anything except like something invasive. |
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So these methods that I'm going to talk about are |
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usually only considered with all the other methods being targeted. |
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No, we're going to show this slide, which is not |
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being used, but hopefully not being used anymore. |
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But, you know, something like in the 1930s where I |
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used electroconvulsive therapy, the reason I put this up is |
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this is kind of something maybe that is popular. |
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You might have seen movies doing this or heard about |
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|
something like this where they put a large current between |
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|
the between across the brain, which is just causing it |
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|
is the large electrical stimulus that is affecting the electrical |
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|
activity in the brain. |
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|
And that then causes changes in the in the neural |
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structure. |
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And that was used. |
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It induces a seizure. |
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And the idea was that it would then help relieve |
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|
symptoms of mental illness. |
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|
So it's highly controversial and there's like severe side effects. |
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|
So, you know, it's been covered in popular media quite, |
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|
quite a lot. |
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So I'm sure you can find more information about that. |
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But it's something that is a historically used technique, but |
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it's not no longer used. |
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But I thought it's useful to just talk about things |
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that are not being used as well. |
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So it's something that's actually much more effective is and |
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currently used a lot. |
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|
It's deep brain stimulation. |
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|
So this is something where you've got electrodes that are |
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|
implanted into the brains of an example of you've got |
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|
a bilateral implant into two parts. |
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|
And it's the common targets include the dynamic nucleus, which |
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|
is around there within the brain of the Globus paladins. |
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|
That's also another structure. |
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Both are within the stratum of the brain. |
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|
So this is so these are implanted. |
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You can see these there's like three little points there. |
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Those are the electrode sites. |
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|
And this is then goes into something like a pacemaker |
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|
that's placed somewhere in the body, which then can be |
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recharged and so on. |
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|
And that's delivering pulses periodically. |
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|
I'm just going to show you a video. |
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|
Of how. |
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This can be quite effective. |
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|
I hope this works. |
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|
So this is a subject with deep brain stimulation on |
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and off. |
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So you can see that. |
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Yeah. |
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They just can do some. |
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|
Tasks or. |
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|
They have this huge tremor that they. |
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|
So you can see it's really effective at alleviating some |
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|
of the symptoms. |
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|
This is a this is a subject with Parkinson's disease. |
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|
Another huge success story. |
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|
To be honest, I don't think we actually we do |
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|
know a little bit about how it works, but some |
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|
of it is a bit of a mystery. |
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|
It just works. |
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|
So that's kind of there's quite a lot of research |
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|
going into how how it's being used and how they |
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|
can improve the design of it right now. |
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|
So yeah, so one of the other things about debate |
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|
simulation before I end the lecture is that it is |
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|
I think coincidentally it has been doing some research going |
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|
into how it might be useful in chronic pain or. |
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|
|
In. |
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|
Depression and so on. |
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|
So there's some trials happening in trying to use it |
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|
in other mental health or other issues, but I think |
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|
these are just kind of coincidental where somebody with an |
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|
implant might show an elevation of other symptoms. |
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|
And so they're exploring these possibilities. |
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|
It wouldn't be implanted in a subject unless it's the |
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|
last it's kind of like the last choice because it's |
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|
|
quite an invasive technique. |
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|
So some advantages of using these simulation techniques is that |
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|
|
while the methods are used as a last resort, there |
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|
|
are some unique advantages. |
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|
So they can be spatially very specific regions of the |
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|
|
brain. |
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|
So this is pretty clear. |
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|
With deep brain stimulation, you get to a specific area |
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|
|
rather than stimulating the whole area by drugs kind of |
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|
|
systemic. |
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|
So it goes across the whole grain. |
|
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|
So there's an exception to this where you can maybe |
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|
|
present an L-dopa drug, which is something for Parkinson's, which |
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|
|
goes just to open the magic cells, or there's some |
|
|
|
new techniques where you've got some designer drugs, where you |
|
|
|
can use some genetics to target specific cell types. |
|
|
|
But this is something that's kind of being geared up |
|
|
|
for the future. |
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|
|
And the other advantage to this, other than being spatially |
|
|
|
specific, is that it can be temporarily specific. |
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|
|
So you could just turn on the stimulation for some |
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|
|
periods of time and run them for short periods. |
|
|
|
I haven't really covered this, but there are some trials |
|
|
|
in using magnetic transcranial magnetic stimulation, which is the magnet |
|
|
|
kind of stimulating and externally. |
|
|
|
And there's some attempt to at that using that for |
|
|
|
depression and other disorders. |
|
|
|
Okay. |
|
|
|
So that's that's it for the lecture today thank you |
|
|
|
very much. |
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|
|
Invited to take a look at this. |
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|
|
Okay. |
|
|
|
Let me just you know I'm for the course. |
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|
|
I guess I'm wondering if it's kind of like it's |
|
|
|
a very different kind of question. |
|
|
|
And I think it's very. |
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|
|
I didn't recognise. |
|
|
|
This. |
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|
|
Right. |
|
|
|
My first. |
|
|
|
Question was, yeah, you know, they looked like that they |
|
|
|
would use classification so they would use. |
|
|
|
But I don't think so. |
|
|
|
I don't. |
|
|
|
Think that's. |
|
|
|
It. |
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|
|
But I think a lot. |
|
|
|
Of it because that's kind of where. |
|
|
|
The question. |
|
|
|
I've read about it. |
|
|
|
Yeah. |
|
|
|
I was wondering. |
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|
|
If you think. |
|
|
|
Different stuff and stuff. |
|
|
|
Yeah. |
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|
|
Yeah. |
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|
|
Yeah, I think so. |
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|
|
Either it's just people. |
|
|
|
People look at the number that people because are looking |
|
|
|
for something better not to excavate. |
|
|
|
You know. |
|
|
|
Some people from different parts of the country or. |
|
|
|
But increasingly critical of the United States is going to |
|
|
|
get to the point where it looks like you're going |
|
|
|
to have to talk to people from different parts. |