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Brainwashing is here?No longer the domain of science fiction, researchers at Medical College of Georgia in the US, have found a way to selectively wipe memories from the brain. So far they’ve only got this working in mice, which is a relief for us all.
Writing in the journal Neuron, Dr Joe Tsien and his team describe their experiments to rapidly change the levels of CaMKII activity in the brains of genetically modified mice. The mice had been engineered so that CaMKII levels can be changed using a simple chemical. The researchers found that temporarily boosting levels of CaMKII affected whether the mice could remember newly-formed memories, or even fear memories from a month before. Then further experiments showed that is wasn’t due to the fact that the mice couldn’t recall the memories, rather that they had been specifically wiped, while other memories were unaffected. If the name of Dr Tsien seems familiar, it may be because back in 1999, he and his team created Doogie, a mouse with enhanced learning and memory skills. Although it might sound like the work of evil scientists, the brain-wiping research could lead to ways to selectively wipe traumatic memories or unwanted phobias. However, Dr Tsien says that we shouldn’t expect human brainwashing to turn up any time soon. He commented that "No one should expect to have a pill do the same in humans any time soon, we are barely at the foot of a very tall mountain."
26th Oct 2008 The Teslathon - High Voltage Fun!David Woodroffe, TeslathonBen - This week also saw the annual Teslathon, held at the Cambridge Museum of Technology. The Teslasthon sees enthusiastic amateurs get together to show off their home made tesla coils – high voltage devices based on the same principal as an electric transformer.
Derek - Teslathon is a group of people who are interested in high voltage electronics, Tesla coils and pretty much anything to do with high voltage, current, static electricity: all sorts of technology-related stuff like that. Ben - So really anything that can make a nice big spark. Derek - That’s very much part of it. Some of us try and make the biggest spark possible. Some of us try and do it in more interesting ways. Of course we try and push the modern technology to do something that couldn’t be done 18th century-wise by Tesla himself. Ben - How do Tesla coils work? They seem a very simple principle. Derek - They are a very simple principle. Effectively it’s a standard transformer with a primary and a secondary. What Tesla did was he also introduced resonance so the primary has an associated capacitance. The secondary has an associated capacitance. The two synchronise with each other and form a resonant coupling, very much like a young child pushing somebody on a swing. You can get a very small movement that can be made into a very large movement just by the process of resonant rise or multiplication. Ben - And this enables you to have huge voltages and this is what gives you these lightning-like forks that seem to be flying across the room behind us. Derek - That’s right. Some of the coils start at about 240 volts. They quite often cheat and go up to 10,000 volts or so into the primary of the coil. Then, due to resonant rise in the way the Tesla coil is constructed we’ll get 100,000 volts or 200,000 volts from the top. But because it is high frequency AC that means we can then push quite a lot of power into a spark or an arc which will then grow much longer than the 100,000 volts sounds. Ben - And that’s why they do seem to be reaching out and fingering their way across the room. There are some really huge forks of lightning across here. Is it actually safe? Derek - No. Is the simple answer. Like most things that are interesting or fun it isn’t safe. You have to be very careful. Most of the people in this room have been doing it for very many years. They know their equipment because they’ve had to build it from scratch. It’s not something you can just go out and buy. There is inherent safety: we all abide by a set of rules for the safe running of these sorts of events. People have to stand back from the equipment. The equipment has to be able to be made safe but obviously there is that inherent danger. Any high voltages, high currents, unpredictable equipment you’ve got to view with a degree of distrust. Ben - I’d imagine that the element of distrust you have means you have to be fairly reserved in public. The people who come along to the Teslathon this weekend won’t really see the full power of what your devices can do. Derek - They will see a limited amount. There are some things certainly that we wouldn’t do in a public environment that we would do in private. Obviously there’s the safety of the public and the people who are watching the Tesla coils here today is absolutely paramount. We don’t want to hurt anybody. It would really ruin the enjoyment of the whole event for everybody. Ben - Cambridge Industrial Museum, where we are today, seems like a very appropriate setting for this. I understand you come back each year to do another Teslathon here. Does it feel like home? Derek - Certainly for me. I’ve been doing this for about seven years now and the actual Teslathon has been here to my knowledge for 9 or 10. It’s usually on the same weekend every year, which for some reason happens to be Halloween. I don’t know whether that’s by planning or by accident! We’ve always been very welcome here and obviously with the connection to 18th century technology we seem to fit in very well with the other machines and equipment at the pumping station. Of course, we all like to go and have a look round that sort of technology too. October 2008 Researchers roll out new way to make x-rays - with sticky tapeUS scientists have made an extraordinary discovery with a roll of sticky tape. By placing the spool in a vacuum and unrolling the tape with a motor they produced a burst of x-rays. Writing in this week's Nature UCLA scientist Carlos Camara and his colleagues describe how they made the discovery whilst investigating the phenomenon of triboluminescence - the process by which materials give out light when they are squeezed or pulled.
Triboluminescence occurs in the sticky tape when the glue is pulled away from the underlying tape layer. The molecules stretch out, separating electrical charges in the adhesive. As they are pulled further apart the voltage between the charges increases to the point where it overcomes the natural resistance of the material and discharges, producing a miniature lightning bolt. This is what produces the visible light. But, the team discovered, things become a lot more interesting if the tape is unwound in a vacuum. Now, the electrons that flow when the material discharges travel much faster because there are no air molecules to slow them down. As a result, when they slam back into the tape surface, they decelerate so quickly that they turn all of their energy into a short, vigorous burst of x-rays strong enough, the team found, to x-ray their fingers! Although no one is advocating turning tape reels into x-ray machines, this breakthrough does represent the most compact and lightweight way yet discovered to produce x-ray light. "This could have all kinds of applications for portable x-ray production in cameras and other imaging devices," suggests Camara.
26th Oct 2008 Rotten eggs regulate blood pressureAs the childhood saying goes, “he who smelt it, dealt it”, and we’re all familiar with that unpleasant whiff of rotten eggs, the ‘pleasant’ perfume released by breaking wind. This is the gas hydrogen sulphide at work.
To find the link, the researchers studied mice missing a gene for an enzyme called CSE, which has long been suspected to make hydrogen sulphide in the body. They measured the levels of the gas in the tissues of these mice, and compared them with normal mice, unsurprisingly finding that the mice lacking CSE had very little hydrogen sulphide. Next, they used tiny blood-pressure cuffs on the mouse’s tails to measure their blood pressure, and found it was around 20% higher in the mice lacking CSE – showing they had serious hypertension. And they also found that blood vessels taken from the CSE-deficient mice hardly relaxed at all when they added a drug that normally relaxes them. Although the work has only been done in mice so far, it’s highly likely that the same systems are at work in humans too. If this sounds familiar, it’s because we’ve known for some time about another gas produced by blood vessel cells, nitric oxide, that has a similar effect. Drugs that affect nitric oxide production are already in use – though one of them, Viagra, is rather more famous for its side effects. Now this new hydrogen sulphide pathway has been discovered, it opens the door for the development of new types of treatment for high blood pressure.
26th Oct 2008 The ST-E-CardDoctors have developed a new technique with which to tackle the problem of sexually transmitted infections (STIs). At the moment when a patient is diagnosed with an STI there follows a laborious contact-tracing process intended to track down, warn, test and treat other partners who might be at risk. This is a very time consuming and costly exercise but is absolutely critical from a public health perspective. Some patients also find it embarrassing.
Their web-based initiative called inSPOT, which stands for Internet Notification Service for Partners or Tricks, is a website with a difference. Users choose from a range of online "greetings" cards which they then customise by selecting the infection with which they have been diagnosed. They can also add a short message if desired. The cards are then sent anonymously via email to recipients identified by the patient. When the recipient receives the e-card it pops-up links to information about the disease they might have caught or be carrying together with a list of the nearest places to seek treatment or advice. Since the system was first launched in San Francisco in 2004 nearly 50,000 e-cards have been sent. It has since been scaled up to many other cities and translated into other languages. About 50% of recipients of the e-cards, it seems, also choose to avail themselves of the information provided when the cards arrive in their inboxes. Although the system relies on patients knowing the electronic contact details of their contacts in order to warn them, the team point out that large numbers of cases of STIs are now occurring amongst people who use the Internet to meet new partners and so, by definition, they usually already have this information. And with one person in ten infected with chlamydia in certain age groups and rates increasing by 100% per year in some areas, this initiative could help to stem the epidemic. But let's just hope that no one starts using it to spread computer viruses!
26th Oct 2008 Warm coffee warms the heartHere at the Naked Scientists we’re all pretty warm-hearted people, but now researchers at Yale University have shown that it might be down to our choice of drinks rather than our nice personalities.
Writing in the latest issue of the journal Science, the researchers have found that people judged others to be more generous and caring if they had just held a warm cup of coffee, but not so nice if they had held an iced coffee. Following on from this, they also found that people are more likely to give something to others if they had just held something warm, but more likely to take if they had held something cold. To test their ideas, the researchers asked volunteers to briefly hold either a warm cup of coffee or iced coffee as they wrote down information. The subjects were then given a packet of information about a person and then asked to assess their personality. The volunteers felt that the person was significantly “warmer”, in personal terms, if they had just been holding the hot coffee, compared with those who held the iced coffee. So physical warmth not only makes us see other people as warmer, but leads us to be more generous and trusting ourselves. This ties in with recent brain imaging studies showing that heat or cold can trigger activity in part of the brain called the insular cortex – the same area is damaged in people who have borderline personality disorder, meaning they can’t co-operate with people or figure out who to trust. The same researchers had previously shown that the physical distance between individuals also influences their judgements about another person. Added to that, this new work suggests that using words to describe people like warm, cold, or distant are more than simple metaphors, but have a more deep-seated meaning.Experiencing Physical Warmth Promotes Interpersonal Warmth Lawrence E. Williams and John A. Bargh Science 24th October 2008: 606-607.
26th Oct 2008 Motor learningConfuse your brain using a mouse. And Ben tries to throw a ball from a differnt perspective. What you need
What to DoGet used to the mouse on your computer Change the sensitivity of the mouse Try using it. Practice for 10 minutes Now turn the sensitivity back again How does it feel now? What may HappenYou should find that when you change the settings it feels all wrong and you keep over or undershooting the icon you are looking for. But as you practice you get better and better at dealing with the new settings until it feels about normal. Then when you change them back you should find that it feels wrong again. We did something very similar on the show. We got Ben to try throwing a ball at me. To start with and his aim wasn't bad. he then put on a pair of glasses which bent the light coming into his eyes by about 15°. This put his aim right off until he had practiced for 5 minutes when he could hit me again with his right hand. But when he tried the left hand which had't had the practice he was still way off.
He then took the goggles off when he could throw straight using his left hand, but his right hand now missed in the opposite direction.
What is going on?When you decide to throw a ball your concious brain sends instructions to your cerebellum - a region at the top of your spinal cord. This then translates the instruction into a series of signals to send individual muscles to move to achieve this task. If this has the desired result then the cerebellum will use the same set of signals next time it is told to throw the ball.
If however something about the throw goes wrong the cerebellum will try doing something different next time, if this is an improvement it will do it again, if it gets worse it will probably tweak the signals in the other direction. This means that if you do something odd like changing the sensitivity of your mouse pointer, or start wearing goggles which move your view of the world then your cerebellum will start fiddling with the strength of the nerve signals, to make the throw or movement work again. However the learning only works for movements you have practiced. If you try another limb, or a different movement it will not have been optimised. So if you take the goggles off or return your mouse setting the unpracticed limb will work fine, but the practiced once will now be compensating for something which is no longer there, and will have to learn how to do the movement again.
Dancing in your GenesPeter Lovatt, University of HertfordshireKat - Time to get your dancing shoes on! It seems that the way you dance could say something about your genetic fitness – in other words, how good your genes would be to pass on to the next generation. Joining us now to explain how dancing could broadcast your fitness is Dr Peter Lovatt, from the University of Hertfordshire. Good evening... Peter - Good evening. Kat - Well, Peter, tell us a bit about why is it important to actually study dancing?
Kat - How does that work? Peter - Two earlier studies have shown that. They asked men in to dance, they filed them into a lab. They filmed them dancing and then blurred the images out so you couldn’t see anything about the physical attributes of the men at all. Then these videos were shown to a large group of women and the women were asked to rate which movements were the most attractive and dominant and masculine. What they found was that the movements of men who have the largest amounts of prenatal testosterone, all men who had higher levels of physical symmetry were rated as more attractive, more dominant and more masculine than the dances of the opposite men. Kat - Does this mean that some people then are basically born dancers. Peter - What it suggests is that according to the original research is that the testosterone has an organising effect on the body movements. The men don’t even know they have high or low testosterone but it influences how they move. It might influence their level of coordination in terms of their movement, or might influence their natural rhythm and how different parts of their bodies move together. Kat - We know there’s loads of programmes on TV here at the moment – you know – ‘Strictly Come Dancing’ and ‘Tap Dance Your Way to Success’ or whatever they’re called. Can people actually learn to dance well or is there always going to be this genetic barrier to it? Peter - I think that people can learn. It might well be the case that your genetic make-up might predetermine the range of your dancing abilities so it might suggest that you’re more rhythmic or you might use more complex movements. Of course then we can teach people a different, wider range of movements or a set of movements that might make them appear more dominant and attractive. Kat - Well, we’re going to try this experiment live now. Are you ready for this Peter? We have our dancing monkey here, Ben Valsler who’s going to do his dance for us. Peter - I’m more than happy. Peter, I know that at the moment you are running a survey online and I’ve watched your video about the different styles of dancing and you want people to let you know – classify their dancing and let you know how they dance. We will link to this from the Naked Scientists.com so people can join in. I think it’s only fair that seeing as Kat hasn’t seen the video that I demonstrate for her in the studio. So please could you describe to Kat the sort of movements that we’re looking for and I will do the movements for you? Kat - So run the music... <Naked Scientists’ theme plays> Peter - So the first set of movements is you just step from one foot to the next foot. Stepping right and touching left. The normal kind of disco movement you see at discos. Kat - It’s what you did at school! Peter - Now keep that quite small and keep the top half of the body doing the same as the bottom half. Kat - This looks brilliant. Peter - Now that is the most unattractive dance that we could do. Kat - You’re telling me! Peter - Now what you can do now, if you keep doing that same thing but do something different with your shoulders. Roll your shoulders backwards slightly and move your arms up. Move your elbows around a little bit. Kat - Ben’s now doing a dancing like your dad kind of dance. Peter - Ooh. As long as your top half is doing something different to your bottom half and it’s in time with the music and there’s a rhythm going on. If there’s a rhythm going on and it’s coordinated then that would be more attractive to women. Apparently. Now f the top half of his body was a bit more random them it wouldn’t be quite so attractive. Kat - Yes, he’s doing some very random things with his arms – over the head – swimming motions. Peter - That’s interesting. If he’s doing all that they might be a bit too big. The bigger the movements are the more dominant they’re seen by people. If they’re large moments and largely coordinated but unthreatening then they could be seen to be attractive and masculine. If they get too big and too random movements then those ones are seen as highly dominant, highly unattractive. Kat - So you’ve got the hands waving over the head now – windmill style. Peter - Yeah, you’re not going to attract any mates that way, I’m afraid. Ben - I’m taking up most of the studio, I think. Kat - I really wish the webcam was working, this is great! Are there any other moves we can get Ben to do or is that the repertoire? Peter - Make the side-to-side a bit bigger so they’re quite small steps but make the bigger. Step about a metre from side to side. Kat - It’s like the Hulk. Peter - And now get the arms swinging out wide. Kat - It’s like he’s doing aerobics. Peter - That’s right. A bit like a star jump. What he’s doing now is making his movement a lot more dominant. Kat - It’s not attractive. Peter - It’s not, is it. It’s interesting you say that because some women do find it attractive. The ones who do that are the younger women – 16-18-19 year-olds often find those movements quite attractive. Kat - So any of our teenage listeners out there, Ben is now the man of your dreams. Peter - He might well be. He might be now – obviously it’s a bit too stylised at the moment. What he needs to do is put a bit more randomness into it. Kat - More randomness. Yep, he’s doing waving his arms now. Peter - Now if you think of being a hip hop dancer and do some big hip hop dancing. Kat - Yeah he’s got some hip hop moves – a bit of arm crossing. He’s doing a little sign with his hands there. Peter - Now all those movements are making him much more obvious on the dance floor. As you’re doing those movements you’re much more likely to see him. As long as he’s not too threatening the younger girls would go for those kinds of moves. They would be impressed. Kat - There you go, Ben. Next time you’re down the teenage disco. The final thing I’d really like to know is, all your studies seem to have focussed on men dancing. In my experience, men don’t dance that well. Is it really true that girls are better dancers than men? Peter - What we’ve done is we’ve just – on the survey we’ve got online at the moment – women are rating themselves as much better dancers than men. The problem is so many girls have had some kind of formal dance training, even if it was only a few years in jazz, tap or ballet when they were much younger. Whereas men often don’t have formal dance training. When we are looking at natural dance – the real sort of dance that’s coming out in their genes it’s less contaminated by training. Kat - So men may be naturally very proficient dancers but they may not know. Peter - Yes, a lot of them might be. Once they relax a bit more you really see some fantastic moves in men. Even if they’re not formally recognisable moves you really see some great rhythm in men. Kat - How long are you conducting this survey for? Peter - We wanted to conduct this survey for as long as we possibly can, really. The survey we are doign at the moment we want to find out how good people think that are at dancing and we want to find out what sort of movements they characterise by their dancing. What we found is that with men under the age of 25, their level of testosterone predicts how good a dancer they say they are. The high testosterone men say they’re good dancers. The low-testosterone men are bad dancers. In the over 25s the pattern goes away but the men are still very good. We want to know what sort of movements men are using with all different ages through their life. You can classify your own dance moves by watching Peter's videos here. Then tell him how well you thinkyou dance on his survey, here. October 2008 Post Traumatic Stress DisorderPeter Naish, Open UniversityBen - Can you trust your memory? It seems that a large proportion of people, when asked, can remember seeing things that they have never had chance to see, such as footage of the London bus bombings that has actually never been shown. While the unreliability of memory is something we should be concerned about in a legal setting, more damaging to our health are the memories that we just cannot forget, such as the debilitating flashbacks occurred by sufferers of Post Traumatic Stress Disorder, or PTSD. 'Memories in Distress' was the title of the talk given at the BA Festival of Science by Peter Naish, who normally resides at the Open University. He explained to Meera how, in PTSD, the brain can be fooled into accepting a memory as if it were happening in front of your eyes. Definitely both a distressing memory and your memory in distress...
Meera - What happens in someone like that’s brain in order for them to actually believe that the ‘dreams’ they’re having are reality? Peter - We have to go back and consider how memory works. The brain really is an information processing system. So all the information that our senses acquire about our world, they have to be analysed so that we can make sense of it. The brain has specialised areas, some that deal with visual processing, some for sound, and even within those there are sub-divisions to do different tasks. Finally, you as it were put it all together and you have your impression of what is going on around you. As the information goes through the brain, it leaves a trace, and that trace is a memory. Now because it’s all distributed, you have to have a process that can assemble things. This seems to revolve around a part of the brain called the hippocampus. It’s the part of the brain that gets bigger in London taxi drivers when they learn the entire A to Z, so wherever you ask them to take you, they know it – just like that! It’s a prodigious memory feat, and their brain actually gets bigger as a result. So the hippocampus gathers together all the relevant little pieces of information for the particular memory you’re trying to resurrect. But there seems to be another system which one imagines must be the more primitive one. When memory got underway for animals, it must have been a thing for safety. If you have a scary experience, and your brain is designed to recognise that it’s dangerous, so you run, the next good thing to do is to remember that – so if some of those scary things start to show up, it triggers exactly the same response. In other words, you feel frightened even if you haven’t seen anything dangerous yet. That is looked after by another part of the brain, not the hippocampus, a region called the amygdala. It would seem that when people get Post Traumatic Stress Disorder, PTSD, it look as if the Amygdala has taken over. So it’s almost like having a library, all the books are our little details and we assemble the little books to get the complete story – that can be done with a good, well ordered librarian, the hippocampus. Or there’s this maniac who just keeps dashing in and getting the books and shoving them under your nose, you’ve got to read them. That is PTSD. Meera - So you’re saying that when someone is taken back to distressing times, the amygdale is pushing out the happier memories from the hippocampus and placing the worse memories in, and that’s what they’re experiencing? Peter - I think the amygdale is principally involved, the story I was just telling, is particularly for post traumatic stress disorder, which is far worse than simply being depressed, although that’s bad enough. The amygdale seems to be involved when the memory simply will not go away, the slightest thing can trigger it. The lady I mentioned who suffered in the tube bombings, she dreads firework night. She hears an explosion and there’s nothing she can do about it, the memory’s there in front of her eyes as if she’s back on that train. Whereas other things will jog your memory, someone says something or you perhaps have a smell that you remember and you think ‘Oh, that takes me all the way back to… whatever’, but you don’t then have to keep thinking about it. It takes you back, it doesn’t make you think you’re there. But the amygdale seems very much to collect all of the raw sensory information coming in, before it’s well processed. It makes something that looks just like it would if information really were coming in. The poor brain, a bit further downstream, doesn’t know the difference. It gets information that seems to be coming from the senses, and it treats it as real. Meera - So now that you know what’s happening in the brain, what is the research being done in order to help people that are having, say, recurring nightmares or Post Traumatic Stress? Peter - We are getting better, we have someone speaking here today, Professor Anka Aylas, together with her colleagues, her husband professor Clarke. They have developed a very nice programme for PTSD, which gently has to take people back in their mind to these, they call them ‘Hot Spots’, the key things that just keep coming back into their minds. And little by little, the ‘sting’ is taken out of it, as it were, and it lets the information be processed really in the proper way. It looks as if it’s letting the hippocampus do its normal job, and that takes over and turns it into a more well behaved memory which will sit on the library shelf until anyone wants it. Of course, these poor people aren’t going to want it in a hurry! Ben - A promising, and surprisingly simple way to tackle Post Traumatic Stress disorder, and let people who have been through disaster return to a normal life. Peter Naish there, talking to Meera Senthilingam at the BA festival of science in Liverpool. October 2008 Beer and BeautyMarcus Munafo, University of BristolKat - Now, the beer goggles, or stella-vision, is a well known phenomenon where a few alcoholic drinks makes other people seem much more attractive, sometimes even leading people to do things they regret. Psychologists at Bristol University have been looking into this effect, and it seems that there’s more to it than it seems at first. We’ve got Marcus Munafo with us to explain a bit more… So Marcus, do beer goggles really exist and what causes them?
Kat - And it’s definitely the alcohol, is there a placebo effect here at all? Marcus - Well, we didn’t compare the placebo drink with nothing so there may have been a placebo effect which we didn’t detect. Certainly, when we compared the placebo condition to the alcohol condition there wasn’t this ten per cent difference. What was interesting was that this didn’t seem to be restricted to opposite sex faces. So we purposefully recruited people who described themselves as heterosexual and even same sex faces were rated as equally more attractive as opposite sex faces. Kat - So you just think everything look great! Marcus - Well, pretty much. At least that’s what the data looked like. What we want to follow this up with is to see to what extent the effect is specific to faces. People weren’t, because we gave a small amount of alcohol, people weren’t saying that they were happier. They weren’t reporting any changes in their mood but they were rating faces as more attractive. There is a question of whether or not we would rate anything as more attractive. Kat - Like art or something like that? Marcus - Like art or landscapes. Things that you could reasonably describe as attractive might show the same effect. So we’re running a follow-up study to look at this now. The interesting thing is this seems to be potentially – we need more studies to find out what’s going on – it seems to be a general effect of alcohol on potentially processing faces but potentially processing anything as attractive. But there was one study which mentioned this in a more naturalistic environment where they went into a bar. They didn’t control for what people had been drinking. They didn’t randomly give people one drink or another so it was a less controlled experiment but it was conducted in a real world environment, if you like. They just asked people how much they’d been drinking and they got them to do something similar to what we did. In that situation then the effect was specific to opposite sex faces. What we think might be happening is that there’s one effect of alcohol which is that it modifies how we process faces, attractiveness and so on. When that occurs in a particular social setting, where there are social cues to do with mate-seeking behaviour and social interaction and so on then that effect becomes targeted among same-sex faces. Kat - If you’re at a typical party it’s not just booze that’s there. There may be cigarettes if you’re at a very exciting party and there may be things like drugs. Do these have an effect? Marcus - This is where it becomes a little bit more interesting. Finding the effect for alcohol is straightforward enough. Alcohol is a drug in much of the western world and it is largely used in social situations. The exact nature of those social situations differs across different countries. But you’re right there are plenty of other drugs that we use including illegal ones very commonly. Caffeine’s one, nicotine’s another one and there are not legal in this country at least which are also used fairly extensively. We looked at nicotine. We did basically exactly the same study which was not an easy study to do because it’s illegal to smoke indoors now. Kat - Bad luck! Marcus - There is an exemption in the legislation for research but for this study we had to do it in the back of a pub which is a more realistic environment so we were sat there with a laptop. It’s quite clever – cigarettes either do or don’t contain nicotine. You smoke a cigarette and you don’t know whether it contains nicotine. Essentially you have a placebo condition and a nicotine condition. What we found was exactly the same effect. The nicotine - what we found that was after one cigarette there was a marked increase in the rate of attractiveness of faces when the cigarette contained nicotine compared to when it didn’t. Kat - That’s really intriguing. Do you know why this might be? Do you think certain pathways in the brain are similarly being activated? Marcus - We know that drugs of use have the capacity to stimulate the reward system and the dopamine pathway in a part of the brain called the nuclear accumbens and that might be part of the reason. Nicotine’s an interesting case in point though because we know quite a lot about hwy nicotine’s addictive and one of the reason’s it’s addictive – nicotine’s not the drug that gives you a powerful psychoactive effect in the same way that alcohol does in cocaine or heroin. Once you’ve had your first 2 or 3 cigarettes you kind of tolerate the strong response you get to those. After that the effect is relatively mild. What nicotine seems to do, and there are animal studies that show this in different experiments, is that they make everything that happens around you slightly more reinforcing. In technological language it non-contingently potentiates the reward value of other things that are happening at the same time. Kat - And another thing you associate alcohol with are not necessarily being attracted to someone but beating them up. If you’re being more attracted to people why does alcohol fuel violence? Marcus - There are lots of social cues that are present in faces. It’s not necessarily the case that alcohol is going to be having uniform effect across all of those different facial cues. One of the things that we get from faces are judgements of attractiveness – in other words we think they might be a potential mate and we might direct our attention towards one sort of person over another, for example. We also get information over what kind of emotion that person is expressing: whether they are looking at us, whether they are a potential threat. There are lots of different cognitive mechanisms and information which is expressed in faces which we can interpret. Alcohol may modify the interpretation of those different pieces of information in slightly different ways. We have a programme of study that’s looking at this: looking at for example, judgements of eye gaze and whether or not people are perceived to be looking at us after you’ve had a drink compared to when you haven’t had a drink. Kat - Kind of, ‘ Are you looking at me?’ Marcus - Exactly that and people certainly do start to see the world in a different way after they’ve taken drugs. This is true for nicotine and alcohol which are the main ones we investigate and there are quite complex and quite subtle effects that we can reproduce in the lab but which in the real world probably interact with all kinds of social cues and the more general dis-inhibiting effect of alcohol as well. October 2008
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