jump to navigation

Encephalon #35 arrives November 7, 2007

Posted by Johan in Abnormal Psychology, Links, Neuroscience.
add a comment

The latest issue of Neuroscience blogging carnival Encephalon is now online over at Primate Diaries.

My two picks of the issue would be two stories on Autism: Not Exactly Rocket Science reports on an experiment that is consistent with the ever-controversial idea that autism is linked with a deficient mirroring system. Also, Medopedia explores some possible reasons why people with Asperberger’s, that is, high-functioning Autism, frequently experience sleep disorders.

In Defense of Electroconvulsive Therapy October 30, 2007

Posted by Johan in Abnormal Psychology, Applied, Emotion.
2 comments

Blogging on Peer-Reviewed ResearchThe TED talks website contains material for a hundred posts, but a video posted earlier today hits particularly close to home. In this talk, Sherwin Nuland, a surgeon turned writer, gives an authoritative and unexpectedly personal account of the history of electroconvulsive therapy (ECT), sometimes known as electric shock therapy. The talk is only about 20 minutes, and gets very interesting around the 7 minute mark where Nuland describes how ECT once saved his life, as he puts it.

If the general public could be accused of placing too much trust in antidepressant medication, the reverse is certainly true of ECT. Ask anyone about electric shock therapy, and they’ll conjure up horror stories, and associations with frontal lobotomy. This is unfair, since there is some evidence that ECT actually works for depression.

The research on this issue has produced mixed results and plenty of controversy, as reviews by Challiner and Griffiths (2000) and by the UK ECT Review Group (2003) outline. However, there is no shortage of positive findings, and this in itself is rather remarkable, when you consider the patients that receive it. Since ECT is considered rather drastic, it is only really considered for patients who are severely depressed, and who have failed to respond to antidepressants. In other words, ECT is usually only considered in cases with the worst possible prognosis, so the fact that it does seem to help at times is quite powerful in itself, given the probability of spontaneous recovery from such conditions. That being said, a read of the ECT literature is unsatisfying. Because ECT is viewed as such a dramatic intervention (even in the absence of evidence that it causes long-term harm), it has rarely been tested on “normal” depressives in random control trials.

As Challiner and Griffiths (2000) outline, a lot of the popular conceptions of ECT are untrue. It doesn’t cause massive spasms – muscle relaxants are administered. It is not going to be a traumatic experience, because you will be put under a general anaesthetic. Although bilateral administration of ECT has been associated with memory loss, this does not appear to happen with unilateral administration, where both electrodes are kept on one side of the head (as shown in the picture at the top).

There is another issue with ECT, which I think bothers practitioners than clients. In the case of antidepressants, we at least know how they work, although it is far from clear why boosting synaptic Serotonin levels should work, given the weak evidence for a lack of Serotonin in depression. With ECT, there are no convincing explanations for either the how or the why. Psychiatrists stumbled upon ECT in the happy days of wild experimentation that preceded Ethics Committees, without much of a theory. It is quite embarrassing that even to this day, we can say so little about what this treatment does, or indeed if it even does anything at all – a pertinent question given the claim on Wikipedia that 1 million people receive ECT each year worldwide.

If I ever developed a severe depression, I would try ECT before antidepressants. Unlike antidepressants, the effects of ECT can be instantaneous, and there are no long-term side-effects, nor any withdrawal symptoms when the treatment ends. Since the treatment is extremely safe when administered properly, there is really very little to lose.

References
Challiner, V., and Griffiths, L. (2000). Electroconvulsive therapy: a review of the literature. Journal of Psychiatric and Mental Health Nursing, 7, 191-198.

The UK ECT Review Group. (2003). Efficacy and safety of electroconvulsive therapy in depressive disorders: a systemic review and meta-analysis. Lancet, 361, 799-808.

What do you know, additives really do cause hyperactivity September 29, 2007

Posted by Johan in Abnormal Psychology, Developmental Psychology, Psychopharmacology.
add a comment

This post is about a very different E211.

A few months back, the menu from of a local Chinese takeaway caught my eye. Apart from the lengthy questionnaire, which customers could complete to receive £2 off (pretty smart way of gathering customer data for a non-chain takeaway), the menu also made numerous claims that all products were absolutely free of additives, including the ubiquitous Monosodium glutamate (MSG) and colourings. This is a good thing, the menu claimed, because additives cause ADHD in children.

My initial reaction was to silently promise myself never to order from that take-away, just as I wouldn’t buy my aspirin in a pharmacy that sells magnet bracelets (although this is a hard rule to follow in the UK, where homeopaths are funded by the NHS), or books from the Christian Science Reading Room. However, it turns out these guys weren’t far off the mark, as a recent study from The Lancet shows (by the way and for the record, this is apparently by no means the first study to report this).

McCann et al (2007) recruited two groups of kids (ages 4 and 8-9), who received two additive cocktails and placebo in different sequences, all disguised in juice. While the exact makeup of the mixes varied, both featured Sodium benzoate (aka, e211). For reference, the contents of one of these mixes was about equivalent to the food colouring present in 2 56-gram packets of sweet for the 3-year-olds, so the doses were not far outside of what a kid might consume on a daily basis.

Using a range of behavioural and peer-rating measures, McCan et al were able to show that on the whole, one of the mixes was associated with increased hyperactive behaviour in the three-year-olds, while both mixes were associated with increase hyperactive behaviour in the 8-9-year-olds. So keeping your kids away from food colouring may not be such a bad idea, after all.

I think this is a beautiful finding, because it’s just the sort of result that I would dismiss as spurious, had it been obtained by an association study, e.g., “hyperactive kids consume more additives than non-hyper kids” (a topic I touched upon recently). It is quite easy to suppose that, for instance, hyperactive kids like sweet, sugary foods with lots of additives better than others, but apparently that isn’t the whole story. This is a prime example of the power of the randomised, double-blind control trial in ruling out alternative accounts.

So either the Chinese takeaway is lucky enough that a belief they held for the wrong reason happens to be true, or someone on staff reads medical journals. I know where to get my Sichuan chicken next time, anyhow.

References
McCann, D., Barrett, A., Cooper, A., Crumpler, D., Dalen L., Grimshaw, K.,Kitchin E., Lok, K., Porteous, L., Prince E., Sonuga-Barke E., Warner, J.O., and Stevenson, J. (In Press – don’t you hate how medics always squeeze in half the department as authors? It’s almost as bad as the human genome project publications. Anyhow, back to the reference). Food additives and hyperactive behaviour in 3-year-old and 8/9-year-old children in the community: a randomised, double-blinded, placebo-controlled trial. The Lancet.

Is is rational to Do No Harm? September 23, 2007

Posted by Johan in Abnormal Psychology, Behavioural Genetics, Emotion, Social Neuroscience.
1 comment so far

From the left: Josef Mengele, Rudolf Hoess, Josef Kramer, and unknown.

The picture above comes from a set recently added to the US Holocaust museum. The pictures have caused a stir since they depict staff at the Auschwitz concentration camp on what might in modern terms be described as corporate kick-offs and the like. I’m not sure why it’s surprising that the prison guards liked to relax and have fun now and then – clearly, they would not have taken up the position if they were not at least acceptant of the task at hand. There is little evidence that the third reich forced or ordered anyone to commit these atrocities, after all.

Mengele is an interesting character. As a leading physician in the camp, he (along with the other physicians) decided who would be sent to work and who would be sent to the gas chambers, as the captives disembarked their trains. He is also infamous for his cruel experiments on inmates. In particular, he collected twins, which were separated from the other inmates, and used to study the heredity of racial traits under much the same principles employed by modern-day twin studies in behavioural genetics, but without ethics committees or indeed basic human decency.

I came across an old NY Times article on Mengele, written by what I assume must be a psychoanalyst. Yes, the usual speculative attempts to explain the man’s behaviour as a function of repressed anxiety appear, but for the most part the article sticks to the story, re-telling the life and work of Mengele through witnesses.

Although this is probably not news to historians, I am struck by the contradictions and inexactness of the accounts, even though this is very recent history. Within the NY Times article, witness accounts frequently contradict eachother: Mengele is described as being an aloof person with no emotions, next he is playful, friendly (even in his role in deciding life and death on the ramp), and entertains his young twin subjects. When comparing the NY Times article to the Wikipedia entry or his entry at the Holocaust History Project, further discrepancies arise.

Yet, a clear picture emerges, and it is one of supreme rationalism and dedication to science (albeit science that turned out to be fundamentally flawed). These are terms that are usually considered positive in our society, so you may be excused if you think me a Nazi apologist for saying so. It’s quite the contrary, however. I think Mengele’s case highlights how the idealised image of the objective Academic, struggling only to further knowledge, can be a road straight to hell.

From a rationalist standpoint, it is relatively easy to understand Mengele’s decisions. As an anthropologist with an interest in heredity, he must have recognised that Auschwitz offered an unprecedented opportunity for all kinds of forbidden experiments. The NY Times article implies that this research opportunity may have been the very reason why he actively sought a position at the camp. From a moral standpoint, the prisoners at Auschwitz were going to suffer terrible suffering or immediate death regardless – one could then argue that Mengele only tries to make the best of the situation by adding to human knowledge, while killing and maiming. For Mengele, the suffering of the prisoners was likely a non-issue in any case, since the man was a rabid anti-semite, and considered his subjects less than human. In this sense, the work may have presented no more of a dilemma to Mengele than the dilemma a contemporary researcher faces in killing a macaque monkey after the conclusion of a single-cell recording study, in order to verify that the electrodes were placed in the right cortical location.

My point here is not to defend Mengele – he was clearly an appalling person who, apart from all other damage done, sullied the name of science. Still today, Mengele is the original template for the evil scientist, who seeks knowledge at any (human) cost. But it is unsatisfying to merely state that Mengele was “evil”, and thus did what he did. The NY Times article finally lets loose the full-on psychoanalysis towards the end, and this explanation proves no more satisfying:

His impulse toward omnipotence and total control of the world around him were means of fending off anxiety and doubt, fears of falling apart – ultimately, fear of death. That fear also activated his sadism and extreme psychic numbing.

I would prefer to invoke the behaviour of patients with damage to the ventromedial prefrontal cortex (VMPFC -the bit of brain just above and between the eyes). These patients display, among other symptoms, what can best be described as a lack of conscience. They are well aware of the conventions of society, but as the post linked above describes, their reasoning is defective. The defects do not appear in the expected, irrational direction, but rather in a rationality that is so extreme that is leads to horrendous decisions. These patients do advocate killing a crying baby in order to avoid the group’s capture and certain death at the hands of enemies. This is the most rational, utilitarian path to take – better the death of one than the death of all.

So did Mengele have an undetected lesion to the VMPFC? I don’t think so, and there is absolutely no way of finding out. Such an account would be as speculative as the psychoanalytic drivel cited above. I only wish to raise the possibility that sometimes, a behaviour as complex as immorality or a lack of conscience may arise from relatively simple lesions. Repressed traumas and anxiety may well cause such cruel behaviour too (who knows?), but a blow to the head strikes me as the more parsimonious explanation, if we’re going to speculate about it anyway

I don’t think Mengele was mad, evil, or suffered from repressed anxiety. He was a dedicated and supremely rational scientist. This is why he caused so much harm.

Detecting genetic disorders with 3d face scans September 16, 2007

Posted by Johan in Abnormal Psychology, AI, Applied, Behavioural Genetics, Developmental Psychology, Face Perception.
add a comment

Following on from last week’s post on smile measuring software, The Scotsman (via Gizmodo) reports on the work by Hammond and colleagues at UCL, who are developing 3d face scans as a quick, inexpensive alternative to genetic testing. This is not as crazy as it sounds at first since it is known that in a number of congenital conditions, the hallmark behavioural, physiological or cognitive deficits are also (conveniently) accompanied by characteristic appearances. The classic example of this is Down syndrome, which you need no software to recognise. More examples appear in the figure above, where you can compare the characteristic appearances of various conditions to the unaffected face in the middle.

Hammond’s software can be used to identify 30 congenital conditions, ranging from Williams syndrome (a sure topic of a future post) to Autism, according to the Scotsman. I know of no facial characteristics of autism, so I would take that part of the story with a grain of salt. The system claims an accuracy rate of over 90 percent, which is not conclusive, but certainly good enough to inform a decision to carry out genetic tests that are. The UCL press release gives some more information about how the software works:

The new method compares a child’s face to similarly aged groups of individuals with known conditions and selects which condition looks the most similar. In order to do this, collections of 3D face images of children and adults with the same genetic condition had to be gathered, as well as controls or individuals with no known genetic condition.

It really is too bad that the software uses 3d images – those cameras are neither cheap nor ubiquitous, which somewhat defeats the point of using this software as an affordable alternative to (or initial screening for) genetic testing. I can’t help but wonder if it wouldn’t be possible to achieve similar accuracy using normal portraits. If you can tell how much someone is smiling in a photo, you should be able to pick up on that extra chromosome…

Follow

Get every new post delivered to your Inbox.