Brainwashing and the Science of Pain

02 April 2006

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Picking apart the inner workings of our brains this week are Irene Tracey, who discusses the neurological origin of pain and how we can reduce pain, Philip Shaw reveals why having a bigger brain does not make you more intelligent, Kathleen Taylor talks about her new book on brainwashing, including whether brainwashing is a real phenomenon and how we can avoid it, and from brainwashing to the bathtub, Derek Thorne scrubs up on density in Kitchen Science.

In this episode

Wearable Boredom Detector

Researchers at the Massachusetts Insitute of Technology (MIT) Media Lab are developing a mobile boredom detector designed to clip onto a pair of glasses and warn the wearer if they are annoying, or even boring the pants off the people they meet. The device is the brain child of MIT's Rana El Kaliouby and she hopes it will make life easier for people with autism who have trouble interpreting the body language of others. It works by relaying images of the facial expressions made by people chatting to the wearer to a handheld computer which analyses the pictures and picks out how the individual is responding to the conversation. Specifically the software focuses on movements of the eyebrows, lips and nose and also tracks nods and shakes of the head, and head tilting, changes in which can be boredom or mood-giveaways. If it spots any of these, the handheld computer vibrates alerting the user to change tack, or draw the conversation to a close. The researchers trained the computer by showing it over 100 eight-second video clips of actors displaying specific emotions. Now, when presented with prevously unseen video clips, the system correctly predict peoples' emotions 90% of the time when analysing actors, and 64% of the time when looking at shots of ordinary people. They're now training their software with footage from movies and webcams, and working on a way to shrink the camera and the handheld computer to a comfortable size.

Saturn's Lop-sided Satellite

An underground ocean may have caused one of Saturn's moons, Enceladus, to topple over by destabilising its spin. Using data from the Cassini spacecraft, Robert Pappalardo and Francis Nimmo from the University of California in Los Angeles discovered the ocean through the presence of geysers in the moon's icy crust. The geysers are currently at the south pole of Enceladus, but the researchers believe that they began life at the the equator. As the hot, low density ocean water broke through the ice to form the geyser, the moon's spin was disrupted and caused the whole moon to tumble. The result was the geyser finally settling in its present place on the south pole. Luckily this is unlikely to happen on Earth due to its massive size, so Caribbean cruisers can leave their Arctic jackets at home!

Mixing two fluids of different densities

Derek - Hello and welcome once again to the Naked Scientists' laboratory where we've got some great science lined up and an experiment that you can do at home. It's really very easy and I think the result may surprise you as well. With us to explain what's going on and how to do the experiment in the first place is Herbert Huppert.

Herbert - What we're going to do is a very basic experiment but one that occurs in many natural and industrial situations where fluid of one density flows into fluid of a different density.

Derek - Ok, so we're going to be doing some mixing of fluids here with some surprising results. Also with us is our helper who will be doing this experiment for us. Could you please give us your name and age?

Chris - I'm Chris and I'm thirteen.

Derek - Thanks for coming along. My duty is to ask you what you like about science?

Chris - I like chemistry and doing experiments and seeing what happens.

Derek - Well we'll be doing experiments today and seeing exactly what happens! At home, if you want to do this experiment, then these are the things you will need. Firstly you need to go to your bath tub or your kitchen sink, although the best effect will be seen in your bath. What you need to do is run the bath and get six or twelve inches of water in the bottom. It doesn't have to be hot water. Then you need a two litre jug and you need to put salt water in it. In two litres of water you'll need at least half a dozen tablespoons of salt. Finally you need to add some food dye to the salt water so that it looks a completely different colour. Now Herbert will instruct as to what to do next.

Herbert - What we're going to do is stand at the end of the bath that's away from the taps and we're going to pour the salty dyed water down side of the bath quite rapidly and see what happens. Chris is going to do this here. We don't quite have a bath as this wouldn't be appropriate in a departmental laboratory. But what we do have is a nice container full of water and Chris has the container with salty water ready to go.

Derek - yes it was a little bit difficult for us to get our bath tub down into the lab but we do have a similar thing which is transparent. However, this is easy to see in your bath or sink as well. Chris is all poised and ready. What do you think is going to happen?

Chris - I think the food colouring will sink to the bottom.

Derek - Ok, well we're ready here to pour the fluid into the tub but we're not going to do it yet as we want you to do it at home. We also want you to tell us your results. We'll do this at the end of the show for real in the lab and Herbert will be giving us an explanation too. So until then it's back to the studio.

Chris - Thanks Derek. Now do note that if you're doing this in your bath be sure to check that it's not porous before putting in food colouring as this may stain your bath. You might want to do it in your kitchen sink if you don't want the danger of a green bath!

LATER ....

Derek - Hello again. Welcome back to the Naked Scientists' laboratory and we are poised and ready to pour some of this salty dyed water into the big tub of just normal water that we've got. So Herbert, would you care to instruct Chris, our helper, what to do.

Herbert - Right Chris, stand at the end away from the plug and then just pour it in to the side of the bath.

Derek - And tell us what you see.

Chris - It's dispersing in the water and going towards the end.

Derek - Ok then. And if we look down from the side and try to get an idea of where it is, top or bottom, what do you see?

Chris - It's at the bottom.

Derek - This tub is totally transparent and if we look from the side we can see that from the top, the water still looks kind of transparent, doesn't it?

Chris - Yeah, it's dark at the bottom and light and then transparent.

Derek - Ok and so we've got a nice layer of blue liquid which is on the base and even from the top as in a bath tub we can still see this effect. So it didn't actually mix in did it? Why do you think that it didn't mix in?

Chris - I think it's because the food colouring is more dense.

Derek - So Herbert then, what we all really want to know is why this happened.

Herbert - Chris made the water heavier by adding the salt. The food colouring hardly changed the density at all. The salt makes it heavy. As he poured it in, the relatively more dense salty water sunk to the bottom and displaced the relatively light clear water. It then ran along the bottom really driven by gravity. Gravity is making it run horizontally along the bottom of the container or the bath and leaves the dyed salty water at the bottom. The heaviest bit of the fluid is at the bottom.

Derek - So the thing is that we did pour it in there quite quickly and yet it's remained at the bottom and it hasn't mixed in. It's not just become one big slightly blue mixture. Why is that?

Herbert - It doesn't mix because the salty water is heavier and separate. In fact, if we waited here Derek, I think we might have to wait maybe about ten or twenty years before it would really mix in effectively. That's a long time for this show.

Derek - It is indeed! We've got live radio to run, we can't wait that long The thing is, it's all water isn't it. It's either water with salt or water without, so it really does strike me as very strange that they don't mix together of their own volition.

Herbert - If I took a relatively heavy tennis ball and I released it in the air and it stayed there, you'd get a bit of a shock. What you'd expect to happen is because it's heavier than the air, it drops to the bottom. The same is true here that you have relatively heavy salty water that goes to the bottom. It can be mixed but you have to give the energy that's needed in order to lift the heavy fluid up and mix it in.

Derek - And of course you at home can actually try that if you like, because you'll notice it won't really mix in. There are ways to add that energy and mix it in. Just quickly, what are the especially good ways to try and mix that in Herbert?

Herbert - There are two different experiments that you might like to do here. One is to take a ruler or your hand and just swirl the ruler round keeping it vertical. Then what you're doing is giving it horizontal motion and there'll be rather little mixing. The other thing you could do is take a spoon and actually move the fluid vertically to lift the heavy fluid up and then it will mix very much better.

Derek - Now then of course we do see this effect around the world in nature. Where do we see this Herbert?

Herbert - Well it happens in lots of different situations but let me just tell you that in the Antarctic when ice forms, it leaves behind the salt and so you get salty water just as Chris has made. It then sinks to the bottom. When this happens at the South Pole, where can it go but north? It's the only direction. In fact we now know that that current ,which is called the Antarctic bottom water current, goes probably as far as fifty degrees north. So it travels a very long way indeed, driven by that excess of salinity.

Derek - Excellent. Thanks very much Herbert and Chris for helping us with this one. What did you think of it?

Chris - Very interesting.

Derek - And are you going to be going home and doing this and preventing everyone in your family from having a wash?

Chris - Definitely.

Derek - Good stuff. We have a convert once again, that's great. Well that's all here from the Naked Scientists' laboratory and we'll be back next time with some more kitchen science for you to do. Until then, goodbye.

- Proof That Einstein Was Right

The Naked Scientists spoke to Dr Simon Rainville from Laval University, Canada

Proof That Einstein Was Right
with Dr Simon Rainville from Laval University, Canada

Chris - E=mc^2 is probably the most important equation in the whole of science and it's one scientific equation that most people will have heard. But how do we know that Einstein was actually right? He was a theoretician and didn't do any experiments. For years people have been assuming that he was right, but now they've gone and tested it. Simon Rainville from the University of Laval in Canada along with his colleagues at MIT have actually done the experiments to prove that E really does equal mc^2.

Simon - One of the most famous equations in all of science is E=mc^2. We've all heard of it. This formula was derived by Einstein about 100 years ago. This formula says that mass and energy are equivalent. What we've done is directly tested this relationship. We independently measured mass 'm' and energy 'E', and 'c' which is the speed of light is constant in our system so we don't have to measure it. We compared these measurements of 'e' and 'm' and we actually found that Einstein is correct.

Chris - So in his grave he's breathing a sigh of relief that he was right. But getting down to the nuts and bolts of it, how did you actually do this? What was the experimental protocol that you followed?

Simon - The idea is that the nuclei of atoms are made of protons and neutrons and these are the building blocks of nuclei. If you shoot neutrons at atoms, sometimes the nucleus will absorb one of these neutrons and become a little bigger. When that happens, there is some energy that binds the neutron to its new nucleus in order to hold it together. Because of the relationship that mass is the same as energy, we know that energy has to come from somewhere. This is because energy is conserved and so it comes from the mass. In other words, the mass of the big nucleus is slightly smaller than the mass of the original nucleus plus the neutron when we conserve them separately.

Chris - How did you actually make those measurements? The kinds of tolerance in your experiments shows to the extent of 0.00004% that E=mc^2 is correct. But how did you actually do it?

Simon - For that we had to measure the energy to that level of precision. That was done by measuring the wavelength of the little gamma rays. When the nucleus relaxes from its excited state after absorbing a neutron, the energy is emitted in the form of gamma rays. These have been measured with a very precise spectrometer and that gives you 'E'. Independently out team at MIT measured the small difference in mass. The way we did that was by isolating a single atom or molecule of the two species or nuclei we were interested in. We put them in the heart of our apparatus, which is a big magnet. Believe it or not, this apparatus allowed us to hold on to these single molecules for weeks and then measure their motion in the trap very precisely, which is proportional to their mass. In fact, the measurements that we're presenting in this paper are the world's most precise mass measurements. That's equivalent to measuring the distance between Boston and Los Angeles with an error less than the width of a human hair.

- Science Update - Antidepressants and Flapping Planes

The Naked Scientists spoke to Chelsea Wald and Bob Hirshon from the AAAS

Science Update - Antidepressants and Flapping Planes
with Chelsea Wald and Bob Hirshon from the AAAS

Helen - We're now going to go over to Chelsea Wald and Bob Hirshon from the AAAS for this week's Science Update. This week we'll be finding out whether anti-depressant drugs really stop you feeling blue, and 'is it bird, is it a plane', we look to the sky for a plane that flaps its wings.

Chelsea - For the Naked Scientists this week we'll be learning about a tiny plane that flaps its wing, but first, the use of antidepressant drugs has sky rocketed in the past two decades. But scientists are examining whether those drugs are really curing depression or simply masking it.

Bob - And according to a new study in mice, the roots of depression may lie in parts of the brain that anti-depressants can't get to. It was led by scientist Eric Nestler at the University of Texas Southwest Medical Centre. His team found that when small mice were repeatedly bullied by larger mice, they lost interest in food, sex and socialising like depressed people. Their brains also shut down production of a key protein in the hippocampus, the part of the brain involved in human depression. Anti-depressants temporarily counteracted the problem but didn't fix the underlying cause.

Eric - This could well be one mechanism of why people on anti-depressants for either depression or post-traumatic stress disorder or social anxiety relate syndromes, often have to remain on their medication for years or sometimes a lifetime.

Bob - These findings could point the way towards a more permanent cure.

Chelsea - Bugs and birds flap their wings. Aeroplanes don't. But now there's an exception to this simple rule of thumb.

Bob - And it's called the DelFly. It's a foot-long plane inspired by the dragonfly and developed by engineering students at Delft University in the Netherlands. Team leader Dan van Genickan says the flapping wings allow the plane to fly fast or slow and even to stop and hover. Thanks to a miniature camera that interacts with computers on the ground, the DelFly can be programmed to recognise almost anything, like safety hazards at a construction site.

Dan - You could tell it to send a signal if it sees a crack in a pipe, for example. Then it just flies around and as soon as it sees something that is predefined, it will give a signal to the base station and say that it's found it.

Bob - Of course it could also be a powerful surveillance tool in foreign combat zones or domestic terrorist targets.

Chelsea - Well that's all for this week's Science Update. Next week we'll hear from a scientist who is studying the link between pain and obesity. Until then, I'm Chelsea Wald.

Bob - And I'm Bob Hirshon for the AAAS, the science society. Back to you Naked Scientists.

- When Size Doesn't Matter

The Naked Scientists spoke to Dr Philip Shaw, US National Institute of Mental Health

When Size Doesn't Matter
with Dr Philip Shaw, US National Institute of Mental Health

Chris - Now people often seem to be undecided when it comes to whether size is important. But in the case of the developing human brain, it looks like brighter children, with higher IQs, are that way inclined because their brains are better at re-organising themselves. Philip Shaw, from the US National Institute of Mental Health in Washington DC, has brain scanned large numbers of children over the course of their development and also measured their IQs. Intriguingly, the most intelligent children often started with the least grey matter but also showed the greatest rate of structural changes in different parts of the brain.

Philip - Basically in this study we asked 'do children's brains develop differently according to how clever they are'? I think the key finding was that the smartest kids differed in how fast the thinking part of their brain changes as they grow up. So in the cleverer children, the cortex or the outer crust of the brain thickens more rapidly and for a longer period of time and then thins faster as well. So I think the main message was that brainy children aren't cleverer because they have more grey matter or more brain at any one age. Instead it's that intelligence is related to the way in which the cortex matures. So children who have very flexible or agile minds also seem to have a very flexible and agile cortex.

Chris - You did this using brain scans didn't you?

Philip - Yes. We worked with people from the Montreal Neurological Institute and we imaged 300 healthy children from about the age of six to the age of twenty. We imaged the majority of them more than once. The children were scanned roughly two or three times at two-yearly intervals and everyone also did an IQ test. This is a standard test which measures verbal and non-verbal knowledge and reasoning. We then split everyone into three groups on the basis of their IQ scores and then compared these three groups and saw how their cortex developed as they grew up.

Chris - Were there any regional differences in different parts of the brain in different individuals at different times?

Philip - Yes we found that the different patterns of growth most marked in the pre-frontal are the front bits of the cortex. That's the part of the brain that we think is the seat of reasoning, planning and other very complex thought functions. What think that the later peak thickness which we find in the pre-frontal cortex in children who are the most intelligent might reflect an extended period for the development of brain circuits, which can support very complex thinking.

Chris - What are the big unanswered questions that this has opened up?

Philip - I think one question is what's the role played by genetic factors. The parts of the brain that differed most according to intelligence overlapped to some degree with brain regions that are thought to be under the tightest genetic control. However I think that what exactly is inherited is unclear. Some researchers suggest that it's the way the child interacts with the environment that's inherited. So a clever child might have genes which incline him or her to evoke a very stimulating environment. The rich and varied experience the child has may then mould and sculpt the brain particularly efficiently.

Chris - So it would be quite interesting actually to follow these on and then subject their own children to the same analysis and see if they develop the same way.

Philip - Yes it would. I think other possibilities would be environmental enrichment in terms of education or working with families. Does this have an impact on how the cortex develops?

- The Science of Pain

The Naked Scientists spoke to Dr Irene Tracey, Oxford University

The Science of Pain
with Dr Irene Tracey, Oxford University

Chris - Now tell us first of all, why do we have to have pain. What role does it serve?

Irene - Well it's a very important role because pain is obviously something that alerts you to the fact that you're going to damage your tissue so it's a self-preserving phenomenon and therefore a very important one. The body has a pretty complicated set of systems geared up for alerting you that something is painful and you'd better do something about it.

Chris - Let's start outside and work our way in then. What sorts of things do we interpret as painful? I don't mean pinches and punches. What's actually going on inside the body to alert nerve fibres that there's something painful happening?

Irene - We do have a set of nerve fibres that specifically detect pain or tissue-damaging types of signals and we generally divide painful stimuli into three broad categories. One would be a thermal type of stimulus, so noxious or unpleasant heat; one would be mechanical like a pin prick, knife wound or a mechanical crushing type pain; and the other type which is less common is chemical pain. That would be something like an acidic pain or if you've ever chopped chilli peppers and then rubbed your eye, you'll realise that it really really hurts afterwards. We have in our peripheral nervous system underneath the skin we've got these specialised fibres and receptors that pick up those three broad categories of pain inducing stimuli. Basically what they do is start the whole process that we call nociception and that is detecting those stimuli. They then send those signals up to the brain and the brain will then unravel all that and tell you that it hurts.

Chris - How does the body discriminate between a tickle or a rub and a painful stimulus?

Irene - Well in terms of them being sensory stimuli, they're all sensory stimuli, so we're aware of where they came from. Whether it's painful and thus if you should withdraw your hand or need to rub it, that's where the brain kicks in and where the type of object causing the pain in the first instance is very important. We're just really starting to understand the difference between the painful phenomena and non-painful phenomena because we've had the ability to look inside the human brain for the first time with these brain imaging tools. A lot of the work we do in Oxford and in other groups around the world is to take normal healthy people, put them in our scanners and image the brain in action as they're detecting those pain stimuli. So we'll take people and give them painful heat, and pressure pain and see how the different parts of the brain respond to that pain inducing stimulus as opposed to something that's not painful, such as just a rub. And what we're finding is that there's a whole network of brain regions that get activated when the situation's painful versus when it's just something normal sensory. That's what we're basically trying to unravel at them moment.

Chris - What about phantom pain? For instance when someone has a part of their body amputated for various reasons they will sometimes say that they can still feel the missing part of the body and that it's painful.

Irene - That's right and that's a very serious condition. There's a couple of different theories describing what's going on there. The most simple one to explain is that where you've lost the limb, you've obviously got raw nerves that have been cut. Those nerves are sending signals into the brain signalling that a very traumatic event occurred and they've just switched on permanently. What can happen after months and years is that brain areas that respond to these painful signals and tell you that this was painful get hard wired and switched on permanently. That can be devastating for the patient because in effect that pain is now being generated by the brain and is as real as if it was happening from the outside and switched on permanently. This is why we need to understand what's going on in the brain so we can then target the therapies.

Chris - One person has suggested that in the same way as that you get that phantom pain from a missing part of the body, that tinnitus could be caused by a bit of your cochlea that's been damaged. This converts sound waves into nerve signals. The missing cochlea is a bit like the missing bit of limb. So your tinnitus is phantom pain in an auditory sense.

Irene - Yes I think that that's exactly right. It's something that is unpleasant. You can broaden out the concept of pain to a very unpleasant smell or taste. This idea of pain being some sensory phenomenon can be broadened out to all the senses, where it's just got to the level where it's very unpleasant and discomforting. People with tinnitus try many methods to get their brains to ignore the unpleasant stimulus.

Chris - Given that you're able to pin point the parts of the brain that are becoming active in these syndromes and phenomena, are we any closer to understanding exactly what's driving these things and how to get rid of them?

Irene - We've done very well over the past ten to fifteen years in terms of understanding that complicated network of structures that have to activate to give you a conscious perception of pain. Now what we're doing is trying to target them selectively with drugs and surgical therapies using things like cognitive behavioural therapies. Why is it that when you listen to a piece of music, it can take your mind off the pain and make the pain less? Why is it that when you get into the fight or flight situation of a sport event that you support quite a traumatic injury but you don't notice it at the time? Then when the event is over and the situation has calmed down they realise that their leg is cut. So we're starting to understand very well actually what the brain is doing in all those different scenarios. So that where it's important for you not to perceive pain because you need to do something immediately then, you can switch the pain signals off. And in other situations where you need to be alert to the fact that it is painful, you can multiply them and make the pain experience much worse. Those amplification and attenuation processes are starting to be understood at a much better level. This bodes very well for the development of drugs and the development of target areas for surgery and rehabilitation.

The wiring of the brain

- Brainwashing

The Naked Scientists spoke to Dr Kathleen Taylor, Oxford University

Brainwashing
with Dr Kathleen Taylor, Oxford University

Chris - The science of brainwashing. Is it really possible to make someone do and think things that they don't want to?

Kathleen - Absolutely.

Chris - Tell us how.

Kathleen - Well there are various ways of doing it. I'm afraid for those looking for the Manchurian candidate process X where you press a magic button and it all goes funny, there is no process X. However, what we do have is a set of psychological techniques that have been developed over many centuries but reached a head in the last half of the twentieth century. This is when they started being used on quite large levels to persuade, coerce, bully and sometimes even torture people into changing the way they thought about the world, changing the information thy used to deal with the world and changing the way that they behaved.

Chris - And what sorts of general examples are we talking about here?

Kathleen - Well the word brainwashing was coined in the Korean War. It was coined by an American journalist called Edward Hunter, who was working for the CIA. He wanted a term to describe what happened to America GIs who were kept in Chinese communist prisoner of war camps, and who came out denouncing the American way of life and denouncing imperialist poison. He couldn't understand why these boys who'd gone in good Americans had come out with an apparent complete reversal of their beliefs. He wanted to call that something, so he called it brainwashing.

Chris - Was it unshakeable this new belief they'd taken on? Was it just a matter of persuading them that perhaps they'd got it wrong and needed to rethink what they'd been told over the last few years?

Kathleen - No. They were there often for quite a long time but in some cases the beliefs lasted for quite a long time. The people became fervent communist converts. In other cases they developed very severe mental illness, psychosis, trauma and the effects were really very devastating in a lot of cases.

Chris - So if you chucked these people in Irene's brain scanner, would you be able to see structural changes in the brain which would be a sign of someone having undergone this kind of therapy, for want of a better term?

Kathleen - It's difficult to know because you wouldn't have a previous case to compare them with. You'd have to study them beforehand, so the brainwashing and then study them afterwards. Of course you can't do that because it's totally unethical to brainwash people. So we don't have an answer to that. We would suspect that you might see changes but whether those would be at that level of such big brain regions that you'd be able to detect them on a scanner is unknown for individual beliefs.

Chris - But you can see that people have changed their behaviour when they've been brainwashed. What about if you zoom in on the brain in a brain scanner? Can you actually give some indication about what bits of the brain are being affected and how they're being affected?

Kathleen - Yes. What you might expect to see is that different areas of the brain are activated in response to different stimuli. For example, an American GI might previously have responded very positively to the American flag. Now he might respond very negatively, so you might get a threat response that you previously associated with communism.

Chris - Is this just training then? Is this just like having a mouse in a cage and doing something nasty to it until it stops doing what gave it a nasty shock?

Kathleen - A certain amount of that it true because these are all basic psychological processes. There's no magic involved.

Chris - Why can't you just undo it then?

Kathleen - Because you're using an awful lot of stress and an awful lot of threat, coercion and sometimes torture as well. That is very traumatising in itself and to get over that takes a lot of therapy.

Chris - So it looks like it can be pretty permanent then?

Kathleen - It's a pretty terrible thing to do to somebody, yes.

Chris - If you'd like to know a little bit more about this, Kathleen has written a book about it call Brainwashing: the science of thought control. It's out at the moment from OUP.

 

- Why does a round pizza come in a square box?

Why does a round pizza come in a square box?

Why does a round pizza come in a square box?

It has to be something to do with stacking them more easily or so they don't roll around in the van! It could also be so that there's somewhere to put the little tub of cheese sauce to dip your crust in afterwards. You need corners for that!

- What are the islets of Langerhans? Why are these areas more richly supplied with blood vessels?

What are the islets of Langerhans? Why are these areas more richly supplied with blood vessels?

What are the islets of Langerhans? Why are these areas more richly supplied with blood vessels?

Put simply, those are the cells in the pancreas that make insulin. The islets of Langerhans contain beta cells, which are sensitive to how much sugar or glucose is washing around in the bloodstream. They tailor how much insulin they make. Insulin is a protein that comes out of the cells, and more is produced the higher the glucose levels. The insulin comes out of the cells and enters the bloodstream through the rich supply of blood vessels. It then goes around the bloodstream telling the cells in the rest of the body to turn on a special transporter, which draws glucose inside the cell rather like a vacuum cleaner. Once it's in the cell, the glucose is then turned into other things like fats and a bigger molecule called glycogen.

- How does meningitis affect the brain?

How does meningitis affect the brain? I had it when I was younger and I think it might have affected my ability to remember things.

How does meningitis affect the brain?

There are a couple of issues with this. Meningitis comes in two flavours or two forms. There's a viral flavour and a bacterial flavour and by far and away the most serious form of meningitis is the bacterial form. This is because, in this instance, you have bacteria physically growing and multiplying in the fluid that surrounds the brain. When they do that they secrete lots of factors that promote intense inflammation and can damage the underlying brain. One of the other things they do is cause inflammation around the nerves that flow through the infected area; these include the auditory nerve that supplies your ears and connects your ears to the brain. If you have a lot of inflammation around these nerve roots, it can unfortunately pinch them off and cause permanent deafness. There are also other problems of course. If people aren't treated in time with meningitis it can be very serious and can result in people dying. Fortunately we now have vaccines that have been introduced and this has brought the mortality right down. In the UK, for instance, in young children, there was a type of meningitis caused by meningitis strain C and that was introduced as a vaccine about five years ago. Since then there's been a dramatic reduction in the number of cases. Among UK adults the most common form is strain B and this still remains a major problem and there is no consistent vaccine for this, so you should be on the look out for signs and symptoms. These include a non-specific feeling grotty for a few days first, and then you start to get a headache. Then you can start to feel quite sick and get scared of the light and your neck can become very very stiff. Then people start to develop a rash which is non-blanching. In other words if you press on the rash with a wine glass or something and look through the glass, the rash doesn't go away. If you have those signs and symptoms, you ought to get checked out by a doctor. The other flavour of meningitis is viral meningitis and this isn't necessarily so bad. This is when a virus infects the membranes that surround the brain and it causes many of the same symptoms but usually these cases are self-limiting, which means they just go away and get better of their own accord. But, if it's caused by the herpes virus (HSV-2, usually) which is the same virus that can cause genital herpes, then you might need to go into hospital for a while and have a drug called aciclovir, which knocks the virus on the head. Thankfully, though, most viral menigitis cases don't have long term sequelae, unlike the bacterial form...

- We all know that music can affect mood. Why does it change our mood?

We all know that music can affect mood. Why does it change our mood?

We all know that music can affect mood. Why does it change our mood?

That's an area that's been looked at with some of these imaging tools because they enable us to look at the human brain in action. Certainly in the context of pain relieving mood when people use music to help relieve a chronic pain syndrome, a very calming pleasant piece of music can not only enable one to be distracted from the pain but it can also induce endogenous opioids. This can be a strategy for cognitive behavioural therapy to help people boost that endogenous system that we've got to get that added benefit. We are less familiar with the actual brain regions that modulate the mood but these are areas that are being looked at in the context of depression and other types of mood disorders and music is one of the areas that is being looked at. We know less about it at the moment.

- Why is my elbow less sensitive to being pinched?

Why is it that when you pinch the excess skin on your elbow you don't feel the pain even if you pinch really quite hard?

Why is my elbow less sensitive to being pinched?

Pinching is a classic example of mechanical pain. If you squeeze mechanically with pressure on any part of your body it's actually quite hard to make it painful unless you've got a bruise or some damage there already. What you might like to do is to take a pin and very carefully try the pin on that part of the elbow compared to another part of the body. What you'll probably see is that the perception of pain to that pin prick is actually pretty similar. It's just specific to this mechanical crushing type of pain and feels as though there are no pain receptors in that part of the skin. That's actually not the case.

- Why is it if you see somebody get punched in the nose, you go ouch?

Why is it if you see somebody get punched in the nose, you go ouch?

Why is it if you see somebody get punched in the nose, you go ouch?

Because it's very important for us to empathise with other people's pain and suffering. It's part of human nature. A very nice experiment was done by Tania Singer just a couple of years ago using imaging. Basically they put women in the scanner and they looked at their brains as they were given a painful stimulus. They then put the women's partners at the end of the scanner and they burnt their partners, but they imaged the women's brains as they watched their partners being burnt. The interesting thing they found in that study was that the areas of the brain that were active when they looked at their partners were pretty much the same areas as those areas active in response to that woman having pain in the first instance. So you basically activate a very similar set of structures, which means you really are having a painful experience yourself watching somebody else. They were very cunning because they actually put women in because they thought that they would empathise better so the control experiment would be to put men in the scanner and see what happens.

- Is there any way we can minimise brainwashing?

Is there any way we can minimise brainwashing?

Is there any way we can minimise brainwashing?

Yes there is. There are many ways to do it but basically they all boil down to learning more about it, educating yourself, learning what's going on and looking at the way people are manipulating you. You can practise by looking at examples on the telly, learning what the tricks and techniques are to manipulate your mind and then once you've learnt those you can get to notice them, pick them out and resist them.

- You cannot tickle yourself but you can cause yourself pain. Why the difference?

In your Christmas special you talked about why you can't tickle yourself because the brain switches it off while you perform the consciou...

You cannot tickle yourself but you can cause yourself pain. Why the difference?

Actually you can tickle yourself and Sarah Jane Blakemore did some nice experiments showing how you can do this. What you have to do is get a tickle stick, and when you move it, it has a delay. So from your movement there's a pause between actually when the thing does a tickle on you. You find that that will actually make you laugh. She did some experiments to show why that is. In terms of the pain bit, if you do prepare and block yourself you can boost those endogenous opioids just like in that fight or flight response or in the placebo effect. When you know the pain's coming and you psyche yourself up for it you can actually just take the edge of it and modulate that pain a little bit.

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