A quick tour of some brain stimulation devices


Alright, so before we get started I might just… We’ve got a couple of the devices up on stage here so I’ll just quickly show you guys what these things actually are. Now which one is that? Ok so this guy here is one of the first one of the older direct current stimulation devices or tDCS so very quickly the way that this works as Paul sort of described quite nicely before this is the one where you actually apply a very light current to the brain so you apply current that runs between these two electrode here and the idea is that there’s some of these current actually passes through the skull and runs across the surface of the brain so this is a very subtle way of trying to manipulate how the neurons naturally fire so you can either hopefully either increase that natural firing or in the opposite case decrease that natural firing. This is becoming gradually more and more sophisticated Nigel, can you not call that older? It’s the only one we have… Sorry Mark, finding stuff up in Queensland… This one here is a slightly newer device of the older one as we can see there’s a lot less wires now which is quite nice there’s a couple more electrodes as well as you could see with our older device there the electrodes are quite large these are now looking to try and get that current a little bit more focal so we can try and really target certain areas of the brain. So that’s direct current stimulation when you hear tDCS or direct current stimulation this is what we’re talking about. Which one are you going to use tonight on Gary? So the other device we have in the lab here well, in the lab here, now giant lab is this device here which is transcranial magnetic stimulation or TMS. As Paul again mentioned before this works in a slightly different way and that the aim of TMS is to actually try and make the brain fire itself so the way that TMS works is we have some copper coils that sit in this coil here we run a very very brief so we’re talking under a thousanth of a second current through this coil and that generates a magnetic field which goes out in this kind of direction so when we pop this onto somebody’s head that magnetic field passes with fairly minimal resistance through the skull and then creates another really small current on anything that conducts electricity underneath like the outside of your brain so generally this is used in two different ways so the first way is what’s called single pulse TMS so in this way we can apply the coil to different areas of the brain and we’re going to try this out in a minute with Gary we can actually make different areas activate now we use this in the lab to try and test sort of how excitable different areas of the brain are. So we can use this to try and determine if someone’s doing a task which parts sort of come online at different points. Well you could also use this to test the difference between healthy people and people that have some kind of a brain disorder to try and find out where the differences in activity are between the two different groups. The second way that we use this is what’s called repetitive TMS so instead of just giving single pulses with repetitive TMS as the name suggests we actually give trains of stimulation which try to mimic the way that the brain naturally fires particularly when it fires during learning and memory so the really important part about repetitive TMS is that it can actually change the brain’s activities for a period of time after the stimulation so usually for around about 30 to 60 minutes so this is important because what we can do is we can use this in the lab again to try and either increase brain activity in certain regions or decrease it in that region and then afterwards have the person perform a task and say whether they’ve got better or worse and in that way try and infer whether that brain area was actually involved in the task. Importantly this is also the type that is used in the clinic as well so slightly differently again instead of just giving coming in one day and having a single session patients will come in over multiple days so maybe once every day for about a month and the aim with this is actually to try and produce longer lasting changes in brain activity. Nigel, we probably will have some questions about it but I’ll hold over any questions until we’ve completed the demonstration and also talk to a home user as well so hang on to your questions sir and anyone else who’s catching my eye wanting to ask questions. I need a microphone. Make sure you keep it in your left hand, Gary ok ok so we’re actually gonna try out some of the single pulse TMS now on Gary Oh what should we look for, should we look for anything in particular Nigel? Yep, so I’ll just take you on a quick tour of the brain before we get started, so that’s it Gary if you just look to your left please there we go, ok, so we’ve got there the frontal region up here which is generally involved in executive functions planning for the future those kinds of things down the side here we have what’s called the temporal lobe which is really important in memory back here we have the parietal cortex which is important in sensory integration and the back here we have what’s called the occipital cortex which is generally involved in vision. The area that we’re interested in today is this strip which sort of runs down along just about Gary’s ear here and this is the part of the brain that’s involved in controlling all of our movement so it’s called the motor cortex. One of the really interesting and important things about the motor cortex is it actually organized in a really specific way so the parts of the brain that control facial movement, smiling, talking, these kinds of things are down here as you move up we get to the areas that control our very dexterous hand movements as we move further up still we have the arm and… what do you call the… the shoulder, lumber parts of the body and up towards the center here going into the middle of the brain we get the leg area so we can actually use TMS to target specific parts of the brain. What we’re gonna be looking for here i’m gonna get Gary just to pop his hand out just down a little bit more than that so that everyone can see he’s got a big long arm so that makes our life easy so what we’re gonna aim for first is we’re going to see whether we can get Gary’s hand area so I’ll just get you to look straight ahead there Gary okay here we go Alright, did everybody see that? you can hear a little click as the machine goes off it’s going off now and you can see that Gary is just sort of giving you a little bit of a wave there that’s nice isn’t it oh ok so as we start to move a little bit further up towards Gary’s arm area towards his shoulder area, I might just have to turn the machine up a little bit for this Oh, dear What have you got yourself into, Gary just lost control ok so you can see you’re really starting to get much more global movements of the whole arm then

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