What do you know, additives really do cause hyperactivity September 29, 2007Posted by Johan in Abnormal Psychology, Developmental Psychology, Psychopharmacology.
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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.
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.
Detecting genetic disorders with 3d face scans September 16, 2007Posted by Johan in Abnormal Psychology, AI, Applied, Behavioural Genetics, Developmental Psychology, Face Perception.
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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…