Month: September 2007

The most unaccountable of machinery

“My own brain is to me the most unaccountable of machinery ‚Äî always buzzing, humming, soaring roaring diving, and then buried in mud. And why? What’s this passion for?”

English novelist Virginia Woolf, writing in a December 28, 1932, letter.

Woolf was one of the most brilliant writers of her generation and a significant influence on the modernist movement of the time.

She also suffered from profound depressions and eventually committed suicide at the age of 59 rather than suffer another mental breakdown.

A recent article in the journal PsyArt examined the work of Woolf and the American poet Sylvia Plath in light of what we now know about the factors that influence the likelihood of suicide.

Link to Wikipedia page on Virginia Woolf.
Link to ‘Suicidal Risk Factors in Lives of Virginia Woolf and Sylvia Plath’.

Lucid dreaming in art and science

The New York Times has a short article on the recent upsurge of interest in both the arts and sciences on lucid dreaming – a form of reflective self-awareness in which you realise you’re dreaming when it occurs.

You can apparently train yourself to increase your chances of having a lucid dream, and proponents say that the self-awareness allows you to change your ‘dream reality’ at will.

Unfortunately, it’s jolly hard to study scientifically, because its rare, unpredictable and you can’t signal when it occurs.

This means its hard even to make simple correlations between lucid dreaming and measures of brain activity.

Although occasional studies have attempted to study it in ‘proficient’ lucid dreamers, it’s also been used as the basis for a philosophical analysis of what it tells us about different types of consciousness.

We normally assume we’re unconscious during sleep, yet lucid dreaming suggests that while we have reflective self-consciousness (usually considered the ‘highest form’ of consciousness), we don’t experience the ‘lower’ form of perceptual conscious awareness to the same degree.

Apparently, The Good Night, a film shortly to appear in cinemas, has lucid dreaming as its central theme. The trailer for the movie is available here as an embedded video.

Link to NYT article ‘Living Your Dreams, in a Manner of Speaking’.

Classic video of split-brain patient online

YouTube hosts a classic video of one of the famous ‘split-brain’ patients who had his corpus callosum surgically cut to treat otherwise untreatable epilepsy, effectively separating the two hemispheres of the brain.

This procedure is intended to stop seizures spreading across the brain and its effects were first studied in depth by Roger Sperry, who won a Nobel prize for his work demonstrating that the patients experienced, in certain situations, a sort of split consciousness.

Split-brain patients have been incredibly important in cognitive neuroscience, because the procedure prevents information travelling from one side of the cortex to the other.

The left-most and right-most areas of your vision go directly to the opposite hemisphere, and the same goes for touch information from your hands. Information from the left hand goes to your right hemisphere and vice versa.

In people who have an intact corpus callosum, the information is then communicated to the other hemisphere as well, so the whole brain has access. In split-brain patients, only one hemisphere has access.

Sperry worked with neuropsychologist Michael Gazzaniga who used this effect to demonstrate how each hemisphere could be specialised for different functions.

In the video, Gazzaniga runs Joe, a split-brain patient, through one of these experiments and demonstrates various interesting effects.

For example, it shows how Joe can read words that appear to the right because they get transmitted to the left hemisphere which is specialised for language.

However, Joe can’t read words that appear to the left, because they get transmitted to the language-limited right hemisphere, but he can draw what the word describes with the appropriate hand, because the right hemisphere is specialised for spatial functions.

He can then look at his own picture, making the information available to the left hemisphere, and only then can he name it.

There have been many variations on these experiments that have demonstrated a number of curious effects about brain specialisation and consciousness, some of which are described in a Scientific American article by Gazzaniga.

One of the most interesting things is that the patients don’t feel that their conscious mind is any different, but their split consciousness can be demonstrated experimentally, as shown in the video.

Link to split-brain video.
Link to copy of SciAm article ‘The Split Brain Revisited’.

Lucky escape from crossbow brain injury

A paper in the British Journal of Oral and Maxillofacial Surgery reports on a remarkable case of a man who tried to commit suicide with a crossbow and shot an arrow through his neck into his brain. Thankfully he survived with seemingly little long-term impairment.

Shadid_et_al_images.jpg

The arrow missed all major blood vessels and did not seem to seriously damage any crucial brain areas, although the gentleman lost some sight due to severing part of the optic nerve.

The case report reads:

A 25-year-old man, presented to the accident and emergency department, after having fired an 18-inch arrow with a metal point from a crossbow just beneath his chin in an attempt to kill himself.

He was known to be addicted to cocaine, was depressed, and had been feeling low for several months. He had tried to explain his state of mind to his girlfriend, and a month later he attempted suicide.

The entry point of the arrow was apparent through the anterior part of the neck, and close to the midline. There was no active bleeding. The arrow crossed the mouth and had passed behind the soft palate, which resulted in mechanical trismus and therefore a potentially difficult intubation.

Nasotracheal fibreoptic intubation [camera through the nose] was eventually completed. With the patient anaesthetised, plain radiographs and computed tomograms (CT) were taken urgently; these showed that the arrow had passed up through the brain, and the tip was protruding through a comminuted fracture of the skull vault.

In view of the location, and to assess soft tissue damage further, a magnetic resonance cerebral angiogram was taken, which showed the anatomy clearly, in particular no vascular injury.

The patient was therefore transferred to the nearest neurosurgical centre for definitive treatment. Under general anaesthesia and together with the maxillofacial surgeons, the arrow was withdrawn gently along the precise path of its insertion. This was followed by profuse bleeding from behind the soft palate and base of skull, which had been anticipated and was controlled by a post-nasal pack. No further intervention proved necessary.

His recovery was uneventful, but he lost the sight in his right eye as a result of damage to the right optic nerve. No other neurological deficit was documented. The patient was given psychiatric care for several months for further management of his depression, which had been the cause of his attempted suicide.

Link to PubMed entry for case report.

Harry Potter, migraines and the neuroscience of self

A funny article in the medical journal Headache discusses Harry Potter’s difficulties with what seems to be a recurrent migraine. This isn’t the first time that Harry has turned up in the medical literature. In fact, he’s made almost 20 appearances so far.

However, this is the first to consider his neurological problems in detail:

Harry Potter and the curse of headache.

Sheftell F, Steiner TJ, Thomas H.

Headache. 2007, Volume 47, Issue 6, p911-6.

Headache disorders are common in children and adolescents. Even young male Wizards are disabled by them. In this article we review Harry Potter’s headaches as described in the biographical series by JK Rowling. Moreover, we attempt to classify them. Regrettably we are not privy to the Wizard system of classifying headache disorders and are therefore limited to the Muggle method, the International Classification of Headache Disorders, 2nd edition (ICHD-II; pdf). Harry’s headaches are recurrent. Although conforming to a basic stereotype, and constant in location, throughout the 6 years of his adolescence so far described they have shown a tendency to progression. Later descriptions include a range of accompanying symptoms. Despite some quite unusual features, they meet all but one of the ICHD-II criteria for migraine, so allowing the diagnosis of 1.6 Probable migraine.

The young wizard also appeared in a recent fMRI study [pdf] that investigated which brain areas would be most active when children and adults thought about themselves compared to others.

In the study, participants were brain scanned while being shown short descriptions and were asked to indicate whether they best described themselves or someone else.

One difficulty is that the ‘someone else’ needs to be well known to both children and adults, so Harry Potter was chosen.

In the final study, when participants judged that the phrase described themself, rather than Harry, the medial (midline) part of the frontal lobes were relatively more active.

Interestingly, this area was significantly more active in children than adults, possibly suggesting that this task requires more effort for children and becomes easier as we age.

Link to PubMed entry for Harry Potter headache article.
Link to abstract of self vs other study.
pdf of self vs other study.

Brain stem may be key to consciousness

An article in this week’s Science News discusses whether the brain stem may play a more central role in consciousness than it’s usually given credit for.

It focuses on children with hydranencephaly, a where the cortex fails to develop in children and instead, the space is filled with cerebral spinal fluid.

Typically, affected children survive only a few months after birth, but those that do survive seem to remarkably more conscious than you would guess based on theories that suggest the cortex is where all the action happens to support consciousness.

Swedish neuroscientist Bjorn Merker wrote an article [pdf] in February’s Behavioural and Brain Sciences journal arguing that these cases suggest we need to rethink our ideas about how the brain supports conscious thought, and perhaps, even consciousness itself.

Merker argues that the brain stem supports an elementary form of conscious thought in kids with hydranencephaly. It also contains auditory structures capable of preserving hearing in someone without a cortex. In contrast, optic nerve damage in hydranencephaly frequently impairs vision, regardless of what the brain stem does.

Self-awareness and other “higher” forms of thought may require cortical contributions. But Merker posits that “primary consciousness,” which he regards as an ability to integrate sensations from the environment with one’s immediate goals and feelings in order to guide behavior, springs from the brain stem.

If he’s right, virtually all vertebrates‚Äîwhich share a similar brain stem design‚Äîbelong to the “primary consciousness” club. Moreover, medical definitions of brain death as a lack of cortical activity would face a serious challenge. At the very least, physicians could no longer assume that individuals with hydranencephaly don’t need pain medication or anesthesia during invasive medical procedures.

Link to Science News article ‘Consciousness in the Raw’.
pdf of BBS article ‘Consciousness without a cerebral cortex’.

2007-09-14 Spike activity

Quick links from the past week in mind and brain news:

Female drug reps turn up surprisingly often as contestants on reality TV. Likely due to the fact that pharma companies make a point of hiring persuasively beautiful young women, such as cheerleaders and beauty queens.

Review of Pinker’s new book slams ‘The Edifice of Pinkerism‘. What a great name for a metal band!

BBC News reports on a randomised controlled trial that found that common food additives increase levels of hyperactivity in children.

Also from BBC News, depression associated with worse overall health.

The New York Times looks at some recent studies which show shown a small but significant link between the reduction in antidepressant prescribing and increase in youth suicide. Other data is more mixed, however.

Yahoo! News has a remarkably in-depth article on the difficulties of US soldiers returning home with brain injuries.

The Wilson Quarterly has a review of ‘Second Nature: Brain Science and Human ¬≠Knowledge’ by neurobiologist Gerald M. Edelman.

Delusional social networkers: A study I did a while ago gets picked up by Three Toed Sloth.

The Menstrual Joy Questionnaire: The Guardian takes a look at one of the more curious corners of psychology research.

SciAm Mind Matters discusses ‘Saying no to yourself: the neural mechanisms of self-control‘.

Interesting reading pattern discovered: When reading, each eye is focused on a different letter for approximately 50% of the time.

The LA Times has more on Elyn Saks, a successful law professor who lives with schizophrenia.

Scientists Spot Brain’s ‘Free Willy‘ Center. Just the title made me laugh out loud. More from Neurocritic on the neuroscience of free will.

The technique is new, but the finding isn’t: 3D face scans show distinctive facial structure for certain genetic syndromes. Media mangle the science, scientist loses his rag.

AddictionInfo has a section of articles on the history of the ‘disease model‘ of addiction.

ScienceDaily with the rather optimistic headline ‘brain network related to intelligence identified’.

Brief description of Capgras Syndrome in the NYT. Contrary to the author’s surprise it’s actually fairly common in older people with dementia and psychosis.

PsychCentral lists the Top 10 bipolar blogs.

Charity Autism Speaks created the traumatic ‘Autism Every Day’ advert. Some people with autism reply with the sardonic ‘Neurotypicalism Every Day’ video.

Would you go to bed with me?

A new book on unusual experiments covers a study by psychologist Russell Clark that involved good-looking researchers approaching strangers of the opposite sex and telling them that they had seen them around and found them very attractive. Then they either asked them for a date, to come back to the researcher’s apartment, or to go to bed with them.

If this seems strangely familiar, it’s because the main set up line for the study (“I have been noticing you around campus. I find you to be attractive. Would you go to bed with me tonight?”) was used almost verbatim for the main hook of the pop song ‘Would you…?’ by Touch and Go.

If you don’t recognise the name, you’ll almost certainly recognise the song, as it was a huge hit in ’98 and has been used almost constantly since for adverts, television and radio.

The original video doesn’t seem to be available online, but there’s a quirky version on YouTube where some Belgian students have created their own video.

It is, as far as I know, the only pop song with lyrics based on the protocol for a psychology experiment.

The results of the study? As if you had to ask, almost all the men said yes, none of the women did.

It doesn’t even come close to the greatest psychology study ever completed though, which also involved beautiful women, sex and danger. But that’ll have to wait for another time.

Link to abstract of study.
Link to brief write-up (via BB).
Link to fan tribute to Touch and Go’s ‘Would you…?’

Moral psychology and religious mistakes

Psychologist Jonathan Haidt has written a thought-provoking essay for Edge which charts the recent revolution in the psychology and neuroscience of moral reasoning and suggests that the current critiques of religion have mischaracterised its true nature, based on these new findings.

Haidt summarises the main tenants of the new science of morality as four main principles:

1) Intuitive primacy but not dictatorship. This is the idea, going back to Wilhelm Wundt and channeled through Robert Zajonc and John Bargh, that the mind is driven by constant flashes of affect in response to everything we see and hear.

2) Moral thinking is for social doing. This is a play on William James‘ pragmatist dictum that thinking is for doing, updated by newer work on Machiavellian intelligence. The basic idea is that we did not evolve language and reasoning because they helped us to find truth; we evolved these skills because they were useful to their bearers, and among their greatest benefits were reputation management and manipulation.

3) Morality binds and builds. This is the idea stated most forcefully by Emile Durkheim that morality is a set of constraints that binds people together into an emergent collective entity.

4) Morality is about more than harm and fairness. In moral psychology and moral philosophy, morality is almost always about how people treat each other. Here’s an influential definition from the Berkeley psychologist Elliot Turiel: morality refers to “prescriptive judgments of justice, rights, and welfare pertaining to how people ought to relate to each other.”

The essay then goes on to discuss how the recent findings in then area apply to the ongoing debate between the ‘new atheists‘ (Dawkins, Dennett, Harris and the like) and religion.

In particular, Haidt suggests that the recent criticisms of religion don’t always reflect the best psychological understanding of what are primarily social, rather than ideological, institutions, and notes research findings showing that religious people tend to be happier and more altruistic than others.

As a self-professed non-believer and high-profile social psychologist, Haidt makes some interesting points that are bound to cause controversy.

Link to essay ‘Moral Psychology and the Misunderstanding of religion’.

The remarkable Princess Alice

I’ve just discovered the remarkable life of Princess Alice of Battenberg, who was Prince Philip’s mother, the current Queen’s mother-in-law.

She was deaf from birth, dedicated her life to charity work and nursing, became psychotic, was diagnosed with schizophrenia and spent two years in a psychiatric hospital, founded an order of nuns, and was declared one of the ‘Righteous among the Nations‘ for risking her life by hiding a Jewish family from the Gestapo when Greece was occupied.

According to the Oxford Dictionary of National Biography she was treated by the psychiatrist Ludwig Binswanger, one of the founders of existential psychology.

Apparently, she was a patient in the same hospital as Vaslav Nijinsky, the legendary ballet dancer and choreographer who succumbed to schizophrenia in his 20s.

Ludwig’s uncle, Otto Binswanger was also a psychiatrist of some note, after whom Binswangers disease, a type of subcortical dementia, is named.

Link to Wikipedia biography of Princess Alice.

Bart Kosko on noise and optimisation

Neural network and ‘fuzzy thinking’ researcher Bart Kosko is briefly interviewed in this month’s Wired where he argues that adding noise to a system, including the human one, may improve performance.

It reminded me of part of a colourful interview he did for the 1998 book Talking Nets: An Oral History of Neural Networks – a wonderful collection of personal memories from key scientists in artificial intelligence.

I like to ask researchers where they get their ideas. The only answer I’ve heard that makes sense is, “You vary your input if you want to vary your output.” Do lots of things. If you’ve gotta take drugs, take drugs. Take long walks, meditate, watch a lot of movies, learn a new language, read different books, argue the other side of the debate – anything you can to vary your stimuli.

And then you have to, as they say, “keep the ass in the seat.” You actually have to sit down and write. Do it in a disciplined way. I think if people have a certain minimal training in mathematics, the problem will take care of itself because neural networks are inherently interesting, and I believe they will stay interesting well into the next century.

The rest of Kosko’s Talking Nets interview covers topics as diverse as libertarian politics, cognitive maps, God, the mathematics of fuzzy systems, the economics of marijuana, organising neural network conferences and cryogenic nanobots.

Link to brief Kosko interview in Wired.
Link to Talking Nets book details.

UPDATE: Thanks to Daniel for finding the full Talking Nets interview on Google Books. You can read it here.

PsychAntenna switches on

PsychAntenna is a database of RSS feeds from psychology and neuroscience resources from all over the internet so you can search and gather sites news to create your own custom news channel.

It includes a wide selection of news websites, but also indexes podcasts, academic journals and blogs.

The site has been created by Australian psychologist Dr Gareth Furber – the same person behind the popular PsychSplash website.

Link to PsychAntenna.

Learn first aid for psychosis

This post tells you to how to help someone who is experiencing psychosis, based on first aid guidelines that have just been published in the medical journal Schizophrenia Bulletin

Psychosis is a mental state where someone might experience hallucinations, unusual beliefs, paranoia, mixed emotions, muddled thoughts, hyper-awareness or show unusual or puzzling behaviour.

The guidelines have been drawn from an international committee of professionals, patients and carers. The detailed points are in table 1 of the paper which is available online as a pdf file.

If you want additional mental health first aid information, there’s more on a dedicated website.

Recognising and acknowledging psychosis

Psychosis is the mental state where someone might experience hallucinations, unusual beliefs, paranoia, mixed emotions, muddled thoughts, hyper-awareness or show unusual or puzzling behaviour. If someone seems distressed or impaired by their experiences, even if they’re quite subtle at first, it’s best not to ignore them and hope they’ll go away. It’s good to give the person the opportunity to discuss the situation.

Approaching someone who might be experiencing psychosis

People experiencing the early stages of psychosis may be worried, and may be concerned about discussing their experiences because of what others might think. Also, the experiences might be frightening in themselves.

The key is to be caring, gentle and non-judgemental. Find somewhere where they can talk safely and that’s free of distractions. Say why you’re worried about them, but avoid talk of mental illness or diagnoses – you could be wrong and it might just make them more frightened. Don’t force a conversation if it’s not wanted and don’t touch them without permission.

Ask the person what will help them feel safe and in control, and allow them to talk about their experiences at their own pace, even if they seem quite unusual to you. Let them know that help is available, and if they don’t want to talk, they’re welcome to talk at a later time.

Giving support

It’s important to respect the person’s beliefs, even if you don’t agree. Someone who is experiencing psychosis might find it hard to distinguish what’s real from what’s not, so telling people that they’re wrong rarely helps. However, it’s always possible to empathise with whatever emotions are stirred up by the experience and this can be very comforting.

Avoid criticising or blaming the person. They may be talking or behaving differently because of their experiences. Although the person might be having some odd experiences and difficulty focusing, their intelligence is unlikely to be affected, so you can talk to them as any other adult. However, sarcasm might be misunderstood by someone who is very suspicious, so should be avoided. Be honest, and don’t make promises you can’t keep.

Dealing with delusions and hallucinations

Delusions (false beliefs) and hallucinations (false experiences) will probably seem real to the person. Avoid denying, dismissing, laughing at, or arguing about their perceived reality. Try not to be alarmed, horrified or embarrassed about any unusual ideas or paranoia.

Dealing with communication difficulties

People with psychosis are often unable to think clearly. Speaking at your normal pace is fine and usually you will be understood perfectly well, but you may need to give the person extra time to absorb and respond to what you say, and you may need to repeat anything they haven’t been able to focus on. The person may seem to show little emotional reaction – but be aware that they may well be feeling strong emotions inside.

Discussing whether to seek professional help

Ask the person if they’ve felt this way before and, if so, what helped then. Find out what sort of assistance the person thinks will help them this time. If the person has supportive family or friends, encourage the person to contact them. The person might need practical or emotional support when using mental health services, and if the person lacks confidence in the medical advice they’ve received, encourage them to get a second opinion.

What to do if the person doesn’t want help

Some people with psychosis don’t realise there’s anything wrong, even when they’re quite distressed or impaired, and may actively resist encouragement to get help. However, many people understand what’s happening and have a right to refuse help. Threatening the person with hospitalisation or mental health law is likely to make matters worse.

If you’re worried about someone you should encourage them to talk to people they trust or get a medical check-up. You may need to be patient, and remain friendly and open to the possibility that the person will seek help in the future as some people will need some time to feel comfortable with the idea.

What to do in a crisis when the person is very unwell

Try to remain as calm as possible, talking in a normal tone of voice and answer any questions the person might have. Your aim is to make the person feel more comfortable and calm the situation.

Try and evaluate whether the person is at risk of being harmed, harming themselves, or is suicidal. If you think this is the case, call for medical assistance immediately. If the situation seems risky, check how to leave and keep yourself safe.

If you need to call medical assistance, make sure they know the seriousness of the situation by describing specific observations about the person. If new people arrive, explain who they are, that they they’re here to help, and how they’re going to assist.

Find out if there’s anyone the person can contact who they trust and might be able to help. If you can help with any requests that aren’t unsafe or unreasonable, it might help the person feel in control.

What to do if the person becomes aggressive

It is very rare that people with even severe psychosis become aggressive. They are much more likely to be a risk to themselves.

However, people who are extremely suspicious, feel persecuted or are worried about their own safety may be jumpy or feel ‘on edge’. The best response is to make the person feel safe and calm. A good way is to lead the way by acting in a calm, reassuring, non-challenging manner. Try to avoid doing anything that might look ‘shifty’ or suspicious or avoid restricting the person’s movement.

Take any threats or warnings seriously. If you are frightened or worried about your own safety leave and call for help. If you call the police, describe any symptoms and immediate concerns and tell them if the person is armed. If possible, explain that you’ve called help to get medical treatment and because you’re worried about their aggressive behaviour.

Brain type responsible for politics, pant wetting

It’s often said that politicians need their head examined, but contrary to recent reports, you’re likely to find out more about whether they wear a hair piece than whether their brains ‘dictate’ their politics.

The fact that there is a brain difference between people with left-wing and right-wing views is hardly news. Because every view we have is supported by the brain, by definition they’ll be a difference somewhere – just as there’s a brain difference between people who prefer London to Paris, strawberry to vanilla, or Britney to Christina.

What is interesting about this new study, is that the researchers have found a difference in the ability to inhibit habitual responses in a ‘detect a letter’ task which was linked to brain activity in the anterior cingulate cortex or ACC – a deep mid-line area in the frontal lobes.

Activity in this area correlates with ‘conflict monitoring’ – the ability to detect a conflict between completing mental demands.

It forms part of the brain’s cognitive control and self-regulation system and when it is triggered, the ACC calls in reinforcements to focus attention – in the form of the upper surface areas of the frontal lobes.

Some cases of people with damage to the ACC seem to have perfectly fine conflict monitoring, so it’s not certain that it’s a clear link, but the evidence increasingly points that way.

So the study found that conservatives showed less ACC activation and were more likely to respond when they weren’t supposed to – in other words, were more habitual in their responding.

Cue media pantwetting about brain types ‘dictating’ politics, conservatives being ‘rigid’ and liberals being more ‘flexible’.

Most of this is over-interpretation and, needless to say, the study only reports an association, so it’s just as likely that preferring conservative politics leads to more habitual responding.

Cognitive Daily have a great analysis of the study and I really recommend it if you want to avoid the hype and actually see what’s genuinely interesting about it.

It’s one of their wonderfully clear explanations and has a demo you can try yourself. Importantly, their pants stay dry throughout.

Link to abstract of scientific study.
Link to fantastic Cognitive Daily analysis.

The awesome power of MRI safety videos

Someone’s uploaded a video which serves both as an important teaching aid for MRI brain scanner safety and a wonderfully entertaining guide to the destructive power of a magnet the size of a small car.

The video itself is a a little bit old, and so has a sort of B-movie quality to it, but which makes it all the more fun.

However, it contains the classic sequence, part of virtually every MRI safety video, where technicians release a steel wrench near the magnet, which then flies through the air and obliterates a number of destructible objects in its path.

The magnetic field is designed to focus on a very specific area, and that’s where your head is placed when you’re scanned.

Any ferrous metals in the room will be drawn towards the centre of the field, probably at speed, which can be quite unfortunate if your head is occupying the same position.

We collected some nice examples of objects stuck in scanners earlier in the year, including chairs, oxygen bottles, and other assorted medical equipment.

If you want to see the sort of force generated by a steel oxygen bottle heading towards the centre of an MR magnet, there’s a short (and somewhat frightening) video on YouTube of some brave MRI technicians demonstrating the effect.

Unfortunately, this is exactly what happened in one tragic case where a six-year-old boy was killed. The incident is now also a standard part of MRI safety training.

However, the danger isn’t only from the ‘missile effect’. Additionally, elongated ferrous objects will try to align with the magnetic field. This is a problem if you have metal implants in your body.

For example, brain surgery to prevent aneurysms (strokes) often involves putting a small metal clip over the blood vessel to clamp it shut, to prevent blood flowing to the burst or weakened area. Nowadays, these clips are not ferrous, so aren’t a problem, but older ones might be affected by magnets.

Having a ferrous metal clip suddenly move inside your head can be disastrous, as it has the potential to shear the blood vessel, causing internal bleeding.

The video also talks about other sorts of possible MR hazards, largely involving the liquid helium and nitrogen boiling off and freezing, poisoning or pressurising the surroundings.

An explosion of an MRI magnetic when the gasses boiled off too quickly was caught on video by a TV news crew which creates quite a spectacular effect.

However, do bear in mind that these incidents are few and far between. Having an MRI is significantly safer than crossing the road.

If you go for an MRI scan, you’ll likely be interviewed and / or examined to make sure you have no metal in your body, and you’ll have all metal removed from you.

If you want to try, you can volunteer for brain scanning experiments where you’ll usually get a small payment and a picture of your brain – contact your local university or teaching hospital.

Link to B-movie style MRI safety video.
Link to video clip of oxygen bottle flying towards MRI scanner.
Link to MRI explosion video.
Link to previous Mind Hacks post on things stuck in scanners.