The myth of the tongue map

I have just discovered Wikipedia’s page on a ‘List of common misconceptions’ that includes, among many other wonders, a great piece about the myth of the tongue taste map.

Different tastes can be detected on all parts of the tongue by taste buds, with slightly increased sensitivities in different locations depending on the person, contrary to the popular belief that specific tastes only correspond to specific mapped sites on the tongue.

The original tongue map was based on a mistranslation of a 1901 German thesis by Boring (an eminent psychologist at Harvard). In addition, there are not 4 but 5 primary tastes. In addition to bitter, sour, salty, and sweet, humans have taste receptors for umami, which is a savory or meaty taste.

You can see the referenced entry here and there’s much more joy on the complete page of misconceptions.

UPDATE: Thanks to commentors Steve and Vinnie for pointing me in the direction of the latest XKCD comic that mentions the ‘common misconceptions’ page. Not my source but a wonderful reference point!


Link to Wikipedia ‘List of common misconceptions’.

Science and the legal high

Nature News has an article by a psychopharmacologist whose experimental drugs appeared on the street – with fatal consequences in some cases – even though he’d only mentioned them in initial scientific studies.

The scientist is David Nichols who was working on drugs chemically related to MDMA or ‘Ecstasy’. However, the compounds he created were being reported for the first time and had never been tested in humans.

A few weeks ago, a colleague sent me a link to an article in the Wall Street Journal. It described a “laboratory-adept European entrepreneur” and his chief chemist, who were mining the scientific literature to find ideas for new designer drugs — dubbed legal highs. I was particularly disturbed to see my name in the article, and that I had “been especially valuable” to their cause. I subsequently received e-mails saying I should stop my research, and that I was an embarrassment to my university.

I have never considered my research to be dangerous, and in fact hoped one day to develop medicines to help people. I have worked for nearly four decades synthesizing and studying drugs that might improve the human condition. One type is designed to alleviate the symptoms of Parkinson’s disease, and it works superbly in monkey models of the disease. That same research seeks drugs to improve memory and cognition in patients who have schizophrenia, one of the most devastating human conditions. The other substances I work on are psychedelic agents such as LSD and mescaline. It’s in that latter area of research that I have published papers about numerous molecules that probably have psychoactive properties in humans. It seems that many of these are now being manufactured and sold as ‘legal highs’.

The article that Nichols refers to is itself both worrying and fascinating as it charts how an out-of-work businessman decided to go into the legal high business and now scours the scientific literature for new compounds to try.

They end up as legal highs, presumably with the minimum of safety testing, and Nichols notes that some deaths have occurred as a result of people taking compounds he never intended to be given to humans.

I recommend both articles as they give an insight into the legal high business from two very different perspectives.

Link to NN ‘Legal highs: dark side of medicinal chemistry’ (via @mocost)
Link to WSJ In Quest for ‘Legal High,’ Chemists Outfox Law.

The new year in sex and science

Dr Petra has her traditional review of the year in sex and sex reporting and makes her predictions for the coming year.

You probably won’t find a better summary of the sex and psychology highlights from 2010, with both the highs and lows of how the media managed their restless desires.

If you read nothing else, don’t miss this paragraph, because it’s not often that sex shops, the African country of Burkina Faso, a dodgy clitoris adoption project and a flying saucer cult get mentioned in the same breath:

April also saw the bizarre case of Clitoraid unfold. What began as a request via twitter and facebook to ‘adopt a clitoris’ soon was a more complex case involving a cult, unclear activities in Burkina Faso, and the support of sex educators and a sex store. A summary of the story can be found here, here and here. Many questions about Clitoraid still remain unanswered, and have caused rifts between sex educators, activists and health/development practitioners. This bad feeling was distressing, particularly since many involved were highly respected within the field of sex education and activism – and because basic respectful approaches to international practice were ignored.

Also don’t miss Dr Petra’s look back at 2010’s predictions and her look forward to what 2011 might hold for the world of sex and science.

And if you’re made of stronger stuff than me, you might even be able to recommend the article without making the obvious ‘crystal balls’ joke.

Link to ‘best and worse science and sex stories 2010’
Link to ‘sex and relationship predictions for 2011’

Words about The Scream

January’s British Journal of Psychiatry has another short article in its fantastic ‘100 words’ series, this time on Edvard Munch’s classic painting ‘The Scream‘.

The image is perhaps one of the most iconic artworks of the 20th century and has spurned as many parodies and light-hearted take offs as straight-up tributes.

However, the BJP piece manages to capture the emotional essence of the original:

Edvard Munch is best known for The Scream, 1893, an image endlessly reproduced in the media to depict mental anguish. Explanations of the meaning behind the image abound, mainly focusing on an outpouring of emotion in response to suffering. Munch’s own explanation is revealed in his diaries, which recall the melancholy of a walk along a bridge with friends. Trembling in fear at the fiery sunset, he sensed ‘how an infinite scream was going through the whole of nature’. This dehumanised figure, into which viewers project their own neuroses, is not screaming but blocking out the scream of its existence.


Link to BJP on ‘The Scream – 100 words’.

The war of the manual of mental illness

Wired covers the battle raging over the next version of the ‘manual of mental illness’ – the American Psychiatric Association’s DSM-5.

The piece discusses how the chief editors of two previous version of the manual, Robert Spitzer and Allen Frances – who edited the DSM-III and DSM-IV, have heavily criticised the proposed new manual for lack of transparency in development (non-disclosure agreements are required) and for ever-widening categories.

We’ve covered the (surprisingly personal ) battle on a couple of occasions but the Wired piece does a great job of getting into the nitty gritty of the arguments.

What the battle over DSM-5 should make clear to all of us—professional and layman alike—is that psychiatric diagnosis will probably always be laden with uncertainty, that the labels doctors give us for our suffering will forever be at least as much the product of negotiations around a conference table as investigations at a lab bench. Regier and Scully are more than willing to acknowledge this.

As Scully puts it, “The DSM will always be provisional; that’s the best we can do.” Regier, for his part, says, “The DSM is not biblical. It’s not on stone tablets.” The real problem is that insurers, juries, and (yes) patients aren’t ready to accept this fact. Nor are psychiatrists ready to lose the authority they derive from seeming to possess scientific certainty about the diseases they treat. After all, the DSM didn’t save the profession, and become a best seller in the bargain, by claiming to be only provisional.

My only gripe with the article is it seems a little star-struck by the idea that mental illness could be validated or even wholly defined by reference to neuroscience, which is a huge category error.

How would we know which aspects of neuroscience to investigate? Clearly, the ones associated with distress and impairment – mental and behavioural concepts that can’t be completely substituted by facts about the function of neurons and neurotransmitters.

That’s not to say that neuroscience isn’t important, essential even, but we can’t define disability purely on a biological basis.

It would be like trying to define poverty purely on how much money you had, without reference to quality of life. We need to know what different amounts of money can do for the people in their real-life situations. Earning $5 a day is not the same in New York and Papua New Guinea.

Not even physical medicine pretends to have completely objective diagnoses, as, by definition, a disorder is defined by the impact it has.

An infectious disease is not solely defined by whether we have certain bacteria or not. First, it must be established that those bacteria cause us problems.

The urge to try and define all mental illnesses in terms of neuroscience is, ironically, more an emotional reaction to criticisms about psychiatry’s vagueness than an achievable scientific aim.

Link to article ‘Inside the Battle to Define Mental Illness’.

Change of pace

Mind Hacks posts may be a little irregular in the future as I’ve just moved location and job. I’ve left the wonderful city of Medellín and am now living in Colombia’s impressive capital, Bogotá.

I’ve also started working as a psychologist for Médecins sans Frontières (Doctors Without Borders if you’re American) and, as you might expect, the pace of work is a little more intense and unpredictable than usual – not least because I will be spending quite a bit of time ‘on the road’ to work with some of the many MSF projects in the rather more troubled areas of the country.

In fact, I hear that some of areas we work in are so badly affected that they don’t even have Twitter, so blogging is likely to be a bit restricted at times.

However, Tom and I are mulling over some interesting new plans and we’ll still both be posting when in internet enabled zones, but you might see a change of pace.

This also seems a great opportunity to thank the psychologists and psychiatrists I had the pleasure of working with in Medellín, especially from the Department of Psychiatry at the University of Antioquia, from whom I learnt a great deal and with whom I had some incredibly enjoyable times.

Muchas gracias a todos!