Monday, 24 October 2011

Sex and the Scanner


I have commented on the ridiculous ways in which the media can use results from scanning experiments before, but I feel I should clarify my position on the issue, particularly with regards to MRI (Magnetic resonance imaging).

(In the interest of fairness, I should point out that I've not had much experience with actually using MRI scanners in my previous research, but I have been a subject for the experiments of others many, many times. I'd estimate I've spent over a day in total in an MRI scanner of some form, so I feel sufficiently qualified to comment on MRI scanning in general in the following piece. However, I may well have many more experienced scanning-centric neuroscientists read this who are able to pick me up on errors that I've made. If so, please feel free to leave comments about this and I'll link to them)

First and foremost, I'm all for MRI scanning and other imaging techniques. It's amazing technology, and a modern privilege that I don't think enough people really appreciate. Until relatively recently, seeing your own brain was very rare. It was possible, but given the typical circumstances that would allow someone to see their own brain in the old days, it was probably the last thing they experienced. What they thought about it was impossible to determine. However, thanks to MRI scanners, seeing detailed images of our own, living brain is a common occurrence these days. One could get quite philosophical about that kind of thing, looking directly at the source of our minds, memories, thoughts, feelings, everything we are and every aspect of our being. The fact that it resembles nothing so much as a steroid-abusing walnut just makes it more unnerving for many.

There seems to be this weird view among a lot of non-neuroscientists (or as we call them, Morlocks) that the only thing preventing a complete understanding of the brain's inner workings was the fact that we couldn't directly observe it. Ergo, once you can observe the brain doing its thing, you can figure out how it works. But it's not like this, at all. A smartphone is an impressive bit of technology, but I doubt many people understand exactly how they work. Prising the cover off and looking at the guts of the device probably won't make it less complicated, more likely the opposite. The brain is like this, except orders of magnitude more complex and made of wobbly grey bits.

So, simply putting someone in an MRI machine and making them do a task will not inevitably show which specific part of the brain processes that task. Human's aren't that simple, any task or action will use several faculties at once, and the relationship between mind and brain is still  relatively poorly understood. Useable results from MRI, or more accurately in this context, fMRI (Functional Magnetic Resonance Imaging) are obtained by analysis of the blood flow to certain brain regions observed during specific activity. Not neural activity directly, but the (supposedly) associated changes in blood flow as the metabolic demands of certain areas increase in line with activity. This is not as easy as it sounds, and I have not tried to make it sound easy. You need baseline activity rates, threshold readings, anatomical precision which differs from person to person, and so on. It's a very useful, but complicated and time-consuming task.

However, most media mentions of scanning 'experiments' seem to think that you just put someone in an MRI scanner, and if you stimulate them in some way then a bit of the brain will light up. That isn't neuroscience, that's 'Operation'. But still, brain scanning is 'cool', so is often shoehorned into the most meaningless 'science' stories.

This is something that irks me a lot, but you learn to put up with it. But sometimes, this sort of thing can reach satirical levels.

I was recently contacted by Dr Petra Boynton via that there twitter. As a rather clued up and intelligent Sex educator who works with the media quite a lot, she's often contacted by TV types who want to get her input on their latest sex-based documentary, a programme format which seems to show no signs of going away. This is understandable, as they offer an intellectual discourse on one of the more intriguing yet taboo aspects of human society. But also, tits!

Sadly, the majority of sex-based programmes seem to deserve the degree of cynicism with which I've just described them. Many seem to be far more concerned with titillating, provoking strong reactions, conforming to the prejudices of a target demographic, or just mawkishly parading the intimate details of strangers around for the audience to gawp at. An evidence-based and rational discussion of sex, sexual behaviour or its myriad features seems to be way down the list of priorities.

But like I said, sometimes these attempts to dress up our morbid fascination with sex as serious scientific investigation crosses a line, and the whole thing just becomes farcical. Dr Boynton was recently contacted and asked to give an opinion on a new programme which aimed to investigate whether a new type of sex toy could provide measurably more pleasure in women who use it (compared to other sex toys). Why? I don't know, even though I was forwarded the email conversation that occurred. But there you go. They did specify that they wanted to do a proper and respectful analysis of women's sexual behaviours and needs, and if that's true then it's a reasonably noble aim. Dr Boynton's response was very reasonable, what with sex research and education being a lot more complex than most people realise. She advised against the use of things like MRI scanners, on the grounds that a) they are usually just used as a shorthand for impressive science visuals and b) have little or no practical use when it comes to sex research.

The TV people have seemingly decided to go with the use of MRI scanners anyway, purely on the grounds that they look impressive and make for good TV. Lacking sufficient expertise in the area, Dr Boynton then tried to get some more persuasive arguments against this approach from more neuroscientific people. Sadly for her, the discipline of Neuroscience, the media and you good people reading this, that included me. So, if you're someone from the media and are thinking about putting together a programme with a setup like this,  please let me explain why this is unwise.

If I've interpreted them correctly, the suggested experiment aim(s) can be summarised as follows;

Use advanced brain imaging techniques to quantitatively demonstrate that a specific sex toy gives women using it more pleasure than other sex toys, and do this in a way which makes enjoyable television

Now, as you can probably tell from my previous ramblings, I have several problems with this. Let's go through them all.
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  •       Measuring 'pleasure' is very difficult: It would be in this context, anyway. There are numerous brain regions that are involved with the processing of rewarding and enjoyable stimuli, I'm not arguing that. But 'pleasure' as a term is like 'intelligence', or 'irony', in that everyone knows what it is, but it's actually quite hard to write down a coherent explanation of it that everyone would agree on. This is even more true of sexual pleasure. How do you measure such a thing? There is no one single thing that every woman finds sexually stimulating (as far as I know), and a person's sexual preferences are a complex neurological system based on their own experiences, biology and so forth. You could feasibly scan the brain activity of a large number of women attempting to achieve sexual pleasure in the exact same way, but the readings would probably be very different. Any data applicable to all of them would probably be too general to be of any use in studying a neurological effect as complex as sexual pleasure. A reputable science programme wouldn't show some meaningless data and then just make their own conclusions, would they?... Would they?... Hello?
  •           Sex and masturbation aren’t the same thing: A minor point, but possibly relevant if you're wanting to make a programme about how sex is perceived/experienced. Although they have a lot of biological and anatomical processes in common, sex and masturbation are perceived and experienced differently. Obviously, as with sex there is at least one other person there, and they tend to be very close (spatially, if not in other ways). This is a very big stimulus (even if one partner does not possess a particularly big stimulus, so to speak) and something that is by definition absent during masturbation, so the sendory processing being done by the bain will be drastically different. Some experiments have apparently revealed that intercourse is a qualitatively different (better?) experience to masturbation, so any results obtained from this TV study may not be applicable to sex, per se.
  •           fMRI requires stimulus to occur in real time: Obviously I don't know the exact set-up for this potential experiment, but I do know that if you want to see what parts of the brain activate in response to specific stimuli, you have to scan the brain while that stimuli is occurring. Ergo, if you want to see what effect a sex toy has on a woman's neural activity, she has to be experiencing it while in the scanner (in this case hving the stimulation occur and then scanning them will give you 'post-coital comedown' data, and that's probably even more vague). Given the remit of the experiment, is this something you can get away with showing on national television? Even if you use the classic 'thermal imaging' cop-out, that's still potentially quite a graphic image to broadcast. I imagine you'll have trouble getting that past the censors, but then I'm not an expert.
  •           fMRI is very sensitive and subjects are secured in place: This is something that really should be flagged up in advance, if you plan to go through with this. Obviously, there are many different types of MRI and maybe I have the wrong idea here, but if you want to do an fMRI, in my experience you have to be very still indeed, as the machine is trying to measure very subtle changes in blood flow through tiny capillaries in a small region of the brain. The precision required to detect such small changes means the subject has their head secured in place very firmly, and usually the rest of the body too. Even minor movements can render the whole thing pointless. Bearing all this in mind, how exactly are you going to measure women's responses to masturbation when they're not allowed to move? Some may prefer to have sex in this manner, but I know women masturbate in a different way to men (this is normally where I'd link to something to back this up, but to be honest writing this piece has already rendered my browser search history quite unspeakable) and it logically must involve a reasonable degree of body movement, particularly if using a sex toy. MRI scanners are also usually require the subject to be inserted into a tube, which necessitates a 'legs closed' bodily arrangement, thus compounding the problem.  If you do want to do this right, you'd probably have to have someone using the sex toy on the women while she's being scanned. In all honesty, I don't think lab techs are trained for this sort of thing. And even if you do somehow get approval to do this, getting to show it on TV would be even more of a headache than the last issue.
  •           Taking mechanical devices into an MRI is seriously not a good idea: Even if you were to get approval for all of the above, and somehow manage to work out a system where you can 'run the experiment', so to speak, how do these sex toys work? Hopefully they're just shaped plastic, but I'm getting the implication that they're mechanical in some way. This should present an insurmountable hurdle as you can't take any metal into an MRI scanner, particularly if it's ferrous. It's best not to even have it in the same room. A lot of people are surprised by this, because if an MRI is completely safe for humans, surely an inanimate metal object would be even less affected by it? But you can use this same logic for a typical bath; a human can sit in the bath without experiencing any ill effects, but throw a toaster in there too and you've got problems. MRI's use incredibly powerful magnets to pick up minute changes revealed by movements in our iron-containing blood. If you've ever watched House, they like showing what happens when tiny amounts of metal find their way into an MRI (I know it's just a TV show, but they've done their research there). Some professionals have also kindly arranged some practical demonstrations. In summary, if you want to have women use a metal-containing sex toy in an fMRI scanner, you may as well have them masturbate using a lit stick of dynamite. It's just as safe, and the results of any 'accidents' would be just as spectacular. I suppose this would make for impressive visuals, but I imagine the sort of audience you'd get for them is not going to be your target demographic.
  •           MRI Scanners; Erotic?: Even if you do manage to get round all the issues mentioned above, being in an MRI scanner is confining, boring, potentially claustrophobic, incredibly loud, very chilly, or possibly all these things at once. Again, I'm not an expert in female sexual preferences, but none of that strikes me as conducive to achieving a state of mind that would be required to achieve orgasm. If you do want to go through with all of this, you'd need the sort of women who would be willing to be filmed masturbating/being masturbated while staying very still in a very distracting and intimidating environment, then having it broadcast on TV. Therefore, the only women you could use would either have some very 'selective' turn-ons, or be the sort of person for whom public displays of bizarre sexual antics are commonplace.  This may be doable, but you're seriously veering away from any noble 'how normal women experience pleasure' ethos you may have started out with.

So, that's why I don't think that programme would work. Even if you do manage to overcome all the problems I've mentioned, what are you left with? Nothing that would give you any useable information, at any rate. It would be cheaper and easier just to set up a fake MRI and have the subjects do whatever it is you want them to do, and just use footage of a different MRI scan, there are plenty around. This may seem dishonest, but it's as scientifically valid as the proposed experiment, and this way is probably much cheaper and frees up an expensive MRI in case anyone wants to do some actual science.

Rant over. I apologise to well intended media types and any disappointed men who have found their way here as a result of a more 'questionable' web search.

Twitter: @garwboy

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4 comments:

Petra Boynton said...

Thanks Dean
my worries about this area come from me being a Social Psychologist.There are many factors about our intimate lives that we need to consider when we 'measure' or 'report' sex and relationships - and many methods we can use to do so.But as I'm not a neurologist I worry when I'm critiquing neurological experiments in sex studies that I'm doing so fairly - hence the request for your help.

My worry is reducing 'sex' just in terms of brain scanning misleads the public about what the study of sex can involve and doesn't really answer any of the questions they have about sex.

In terms of your post there are a few points where I'd encourage further reflection:
The point about sex and masturbation being different is kind of right. Most people do draw a distinction between penis in vagina intercourse and masturbation, but often this is a false division and when people are asked to talk about what 'sex' means they describe a wide range of behaviours,feelings,desires,actions.I think in relation to the point you're making about how this fits within a scanning experiment regarding what people do to get turned on is valid. However the studies that suggest 'sex' is 'better' than 'masturbation' are highly flawed and come with a lot of negative judgements about female sexuality in particular so I'd be cautious about using them without that made clear. (If you want I can share some links to criticisms of them).

It's also not accurate that women who have a lot of sex alter their physiology. While I know your blog is humorous and I get the joke, some could interpret what you've posted as judging women who are sexual. Within sex research we aren't value free but we do try not to judge people on their sexual lives, so we don't use terms like 'promiscuous' as they're very loaded and also very difficult to measure - how much is too much and who gets to define?

You are right about how lab studies of this kind will be flawed by only particular participants being able to 'perform'. I hear from a lot of people who are very keen to be in a 'sex study' because their kink IS to be in a confined space, being made to go through sexual 'experiments' at the hand of a researcher. What most want is not really to be in a research study, but to either share their fantasies or to find out where they might be able to make them a reality. Those who do want to do research within fMRIs are going to be different as they'll be able to be excited in spite of or because of the setting. Which may make them interesting to study but not representative of the rest of us. And that core point seems to be endlessly lost on tv researchers.

Thanks again for taking the time to write this, I suspect the next time I'm asked about a 'science of sex' programme and I mention your concerns as a neurologist to the programme makers they'll still ignore us, but certainly our conversations about this issue have helped me understand more about this particular approach.

Not least the elf n safety issue of using a sex toy with metal parts in a scanner. It had never occurred to me this could be dangerous, so preoccupied was I with talking about the complexities of intimacy and philosophy of methods. I'm a lot wiser about very basic information as a result of these exchanges and that has been much appreciated.

Dean Burnett, Neuroscientist said...

[R.E. Comment above]

Petra is referencing a passage in the first version of this blog that I've since deleted. It was essentially a joke about Katie 'Jordan' Price and her worrying sexual history. It was intended as a harmless jibe at someone I find quite unpleasant and was based on a conversation between myself and a female friend, but reading it out of context it just looked like I was saying how some women are whores and have bigger nether-regions as a result. This is ridiculous, of course, but still, it added a sour note to what was meant to be an informative/humorous blog.

Cheers to everyone who pointed it out, but rest assured I shall destroy you all if you dare criticise me again.

Neuroskeptic said...

I can see a few problems with this, but it could work.

The point about metallic devices in the MRI scanner means you just couldn't do this with anything containing ferrous metal which probably means anything motorized / electronic.

Trying to take one of those into the MR room would be a disaster.

But even if an electronic device was magnet safe (it's possible, if you avoid iron etc.) it probably wouldn't work in the scanner anyway. So this would only work with something purely made of plastic.

Unless you went for a neuroimaging technique that didn't involve MRI. PET scanning would work but it's a massive hassle and involves a (albeit very small) risk of cancer as it involves radiation. Also lots of blood tests etc. and a lot of money.

But actually PET wouldn't work unless the woman was post-menopausal because the risk of radiation to the unborn (and any pre-menopausal women has to be considered possibly pregnant in this context, better safe than sorry) means you don't do PET on women for research, let alone for TV, only for medical reasons.

So... it's fMRI or nothing. Assuming you found an MRI safe set of devices, you could try it. Movement in the MRI scanner would ruin the results but you could fix their head in place - it's only head movement that really matters, so long as the head is secured, you can move your body all you like.

However even if all the technical problems were solved, the sensitivity of fMRI in individual cases is not great, you might find that your volunteer's brain just doesn't "light up" in the expected way - I'd say based on my experience (not with this kind of study but with fMRI) that it would be 50/50 at best whether any given person would give usable results in this kind of thing.

Murfomurf said...

If any of the psychological and physical assumptions about the "experiment" were thought to be valid, then a head-only MRI scanner would solve the metal/fried-human aspect. However, the whole project seems doomed by the poorly educated instigators! Here is a link to Uni of Alabama [Birmingham]'s head-only scanner: http://birminghammedicalnews.com/news.php?viewStory=956
Sorry I couldn't be bothered finding a peer-reviewed reference - I'm an unemployed mental health/public health researcher and have only dreamed of having access to an fMRI scanner!.

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