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  • October 11, 2011
  • 01:55 PM
  • 1,099 views

B12, Cognition and Brain Aging

by William Yates, M.D. in Brain Posts

Molecular Model of B12-cyanocobalaminVitamin B12 is known to be important in the preservation of cognitive function in elderly populations.  I have previously reported on a study suggesting B vitamin supplementation may be related to reduction in the rate of brain atrophy associated with aging.A study of vitamin B12-related markers, cognition and brain MRI measures was recently published in the journal Neurology.  This study lends support to the importance of B12 and brain aging.  Additionally, the study suggests testing simply for blood vitamin B12 blood levels may not be the most sensitive method of assessing B12 status.Tangney and colleagues from Rush University Medical Center collected serum B12-related markers in a series of 112 elderly individuals.  An average of 4.5 years later, this cohort had standardized cognitive testing and brain MRI structural assessments.B12-related serum markers assessed at baseline in this study included:vitamin B12 levelshomocysteine levelsmethylmalonic acid (MMA) levelscystathionine levels2-methylcitric acidCognitive function tests obtained at follow up included:perceptual speedvisual working memorysemantic memoryepisodic memoryperceptual organization/visuospatialglobal cognitionMRI measurements included total brain volume, presence of cerebral infarcts and volume of brain abnormalities known as white matter hyperintensities.  The clinical significance of brain white matter hyperintensities is unclear.  However, in a previous post I reviewed a study suggesting these lesions are linked to higher rates of stroke, dementia and mortality.The authors found global cognitive function was linked to all B12-related serum markers except for serum B12 levels itself.   Performance on several specific cognitive tests was impaired with specific B12-related markers (MMA levels with perceptual speed and episodic memory impairment, cystathionine and 2-methyl citric acid with impaired episodic and semantic memory). As for the brain MRI measurements, elevated homocysteine levels were linked to decreased brain volume and increased volume of white matter hyperintensities.Homocysteine levels increase with vitamin B12 deficiency.  However, there are other pathways to elevated homocysteine.  In contrast, elevated MMA levels are specific to vitamin B12 deficiency. The authors of this study suggest vitamin B12 deficiency may have adverse brain effects in more than one pathway--through increased MMA levels and cognitive impairment and through increased homocysteine levels and increased white matter hyperintensities and reduced brain volume.  They note "Marginal vitamin B12 status in older age is frequently missed by measurement of serum vitamin B12 levels alone".Molecular model of vitamin B12 cyanocobalamin from Wikipedia Commons file authored by Ben Mills.Tangney, C., Aggarwal, N., Li, H., Wilson, R., DeCarli, C., Evans, D., & Morris, M. (2011). Vitamin B12, cognition, and brain MRI measures: A cross-sectional examination Neurology, 77 (13), 1276-1282 DOI: 10.1212/WNL.0b013e3182315a33... Read more »

Tangney, C., Aggarwal, N., Li, H., Wilson, R., DeCarli, C., Evans, D., & Morris, M. (2011) Vitamin B12, cognition, and brain MRI measures: A cross-sectional examination. Neurology, 77(13), 1276-1282. DOI: 10.1212/WNL.0b013e3182315a33  

  • October 11, 2011
  • 01:36 PM
  • 1,872 views

How many calories are in that burger?: Do our estimates become more accurate with labelling

by Mr Epidemiology in Mr Epidemiology

 Recently, there has been a push to mandate labelling in fast food restaurants and stores. In the US, this is a huge initiative, passed as part of the 2010 Health Reform Bill (for another view on this, check out Dr Yoni Freedhoff’s post). This Bill mandated that all restaurants with more than 20 locations nationally [...]... Read more »

  • October 11, 2011
  • 01:13 PM
  • 566 views

Bacterial spam mail

by microbelog in Microbelog

History dictates that Alexander Fleming will be best remembered for his discovery of penicillin, what with him winning the Nobel Prize and all. Perhaps what he should be remembered for, however, are the paintings he made on agar using different coloured bacteria. Quite why this culturally important art form never caught on is anybody’s guess. [...]... Read more »

Palacios MA, Benito-Peña E, Manesse M, Mazzeo AD, Lafratta CN, Whitesides GM, & Walt DR. (2011) InfoBiology by printed arrays of microorganism colonies for timed and on-demand release of messages. Proceedings of the National Academy of Sciences of the United States of America, 108(40), 16510-4. PMID: 21949364  

  • October 11, 2011
  • 11:49 AM
  • 1,167 views

In the news this month: a primitive star in our own backyard

by Megan in Rigel

Our current model of the early universe says that, as it expanded and cooled after the Big Bang, quarks began to coalesce to form protons and neutrons which, when the temperature dropped far enough, began to form simple nuclei. Eventually this material, mainly hydrogen with some helium and trace amounts of lithium, began to clump together, forming the stars and galaxies that we see today. Heavier elements such as carbon, nitrogen and oxygen, in fact pretty much everything that makes up this planet and all the life on it, were created later by processing of this primitive material in stars and supernova explosions. This processing in nuclear fusion reactions produces all the heavier elements that make up the universe. Since less massive stars last longer before running out of fuel, there should be a population of very low mass stars which have been around since the early days of the universe. Such stars would be small, dim, and have an extremely low proportion of elements heavier than hydrogen and helium and, in , a team led by Elisabetta Caffau at the University of Heidelberg in Germany have found just such a star in the halo of the Milky Way, but with an unusual chemical make-up., located in the constellation of Leo and known as , has been found to have the lowest amount of elements heavier than helium of all stars yet studied, a quantity known as metalicity. While a few other primitive stars with very low metalicities have been found, the others all have carbon, nitrogen and oxygen in far greater quantities than would be expected for stars from the very first population. It is thought that low mass stars such as these could only form after the interstellar gas had been enriched by supernova explosions with elements such as carbon and oxygen, since these elements act as a vital cooling agent, reducing the temperature of the gas cloud to the point where gravity can begin to overcome pressure and cause the clumping which eventually leads to stars. This conclusion means that the low abundance of elements including carbon, nitrogen and oxygen in the newly discovered star with current models of star formation in the early universe.A further puzzle with this star is the amount of lithium it contains; it's lithium abundance is at least 50 times smaller than that predicted by big bang nucleosynthesis. The likely explanation is that the stellar material must have experienced temperatures ;2 million K, the temperature required to destroy lithium. While the chemical composition of this star is something of a challenge to current models of early star formation, along with other examples that should be unearthed in planned surveys, it should provide clues which will help in our understanding of the very first stellar population.This blog post is a news story from the , aired in the edition.... Read more »

Caffau, E., Bonifacio, P., François, P., Sbordone, L., Monaco, L., Spite, M., Spite, F., Ludwig, H., Cayrel, R., Zaggia, S.... (2011) An extremely primitive star in the Galactic halo. Nature, 477(7362), 67-69. DOI: 10.1038/nature10377  

  • October 11, 2011
  • 11:23 AM
  • 896 views

Interested in human nature?

by Henkjan Honing in Music Matters

During a partner meeting yesterday evening at the residence of the Amsterdam municipality, the majority of the speakers list was released for the 2011 edition of the TEDxAmsterdam event. The speakers and the audience will enter the theme ‘Human Nature’ on an expedition to find out what it means to be human in a society that is increasingly dominated by technology and economical issues.... Read more »

  • October 11, 2011
  • 11:10 AM
  • 1,174 views

Monkeys feel with virtual limbs

by United Academics in United Academics

People can do a lot with a prosthesis, however actually feeling things is difficult. Scientists are working on a solution.
... Read more »

O'Doherty JE, Lebedev MA, Ifft PJ, Zhuang KZ, Shokur S, Bleuler H, & Nicolelis MA. (2011) Active tactile exploration using a brain-machine-brain interface. Nature. PMID: 21976021  

  • October 11, 2011
  • 11:02 AM
  • 1,333 views

The Impact of Ralph Steinman

by Brooke N in Smaller Questions

A short review of the impact of Ralph Steinman on DC literature and Immunology in general.... Read more »

Steinman, R., & Banchereau, J. (2007) Taking dendritic cells into medicine. Nature, 449(7161), 419-426. DOI: 10.1038/nature06175  

  • October 11, 2011
  • 10:45 AM
  • 1,679 views

Cremation Sites in the Roman Empire

by Katy Meyers Emery in Bones Don't Lie

Cremation was one of the primary forms of burial for Roman period until the rise of Christianity in the 3rd century CE. However, within archaeology, cremations have been understudied in comparison to inhumation. It cannot be assumed that evidence gleaned … Continue reading →... Read more »

Mauro Rottoli and Elisabetta Castiglioni. (2010) Plant offerings from Roman cremations in northern Italy: a review. VEGETATION HISTORY AND ARCHAEOBOTANY, 20(5), 495-506. info:/

  • October 11, 2011
  • 09:30 AM
  • 1,626 views

Mapping Parasites in Ancient Italy

by Kristina Killgrove in Powered By Osteons

Last week, Dr. Bethany Turner of Georgia State University gave a talk at Vanderbilt called, “Diet versus locale: isotopic support for causal influences in pathological conditions at Machu Picchu, Peru.” Bethany’s work centers on analysis of skeletal remains for multiple isotopes – Sr, O, Pb, C, and N – to investigate the heterogeneity of the population, which was composed of slaves, short-term (non-local) laborers, and locals. I greatly enjoyed the talk because, even though Machu Picchu is far removed in time and place, Bethany and I are using similar methods to answer similar questions about physical mobility in the past. Imperial Rome also, of course, had millions of slaves, as well as free immigrants who came looking for work and locals who were born there.

One of Bethany’s research questions was whether the immigrants were less healthy than the locals. In my dissertation research (Killgrove 2010), I investigated the frequencies of common diseases – osteoarthritis, dental caries, abscesses, linear enamel hypoplasias, and porotic hyperostosis – and found that immigrants to Rome were not significantly less healthy than locals, although they did seem to die at an earlier age (possibly of new diseases they were not immune to, possibly because the immigrant population had a different demographic profile than the locals did). Bethany took a slightly different approach to this question: she looked at porotic hyperostosis, which is a bony reaction to anemia that develops in childhood, and found that it was significantly correlated with oxygen isotopes.

Backing up a bit, anemia has many causes, but it often results from diet or from parasites, although it can also be the result of a genetic condition (such as sickle-cell anemia or thalassemia). If a person eats too much maize, for example, that individual is at greater risk of developing a dietary anemia because maize is low in iron. This also holds for millet, which is much lower in iron than its C3 cousins, wheat and barley.  So people with high carbon isotope values indicative of C4 (maize/millet) consumption may be expected to have higher frequencies of porotic hyperostosis if diet was the primary contributing factor to anemia. But people who grew up in an area without clean water, particularly an area with a large parasite load like hookworms, may also be at great risk of developing anemia when the parasite attaches to the intestinal lining and robs its host of needed nutrients like iron.

To distinguish between dietary and parasitic anemias as a cause of porotic hyperostosis, Bethany graphed her Machu Picchu individuals on a carbon/oxygen scatterplot. She found two fairly distinct groups of people along the oxygen axis: those with porotic hyperostosis and those without. This clustering she interpreted along the lines of Blom et al. 2005, who argued that a latitudinal patterning of porotic hyperostosis along the coast of Peru and a tendency for childhood anemia to be present in populations from more humid environments may be related to high parasite loads in certain locations rather than to differences in diet.  In fact, Bethany’s data did not vary much on the carbon axis, further suggesting a parasitic origin for anemia rather than a dietary one.

Since I have all the same data from my two Roman populations, I created a similar graph to see what patterns there were in the carbon, oxygen, and porotic hyperostosis data. In the scatterplot below, individuals with and without porotic hyperostosis are plotted, and the yellow box represents the “local” oxygen isotope range of Rome:



C and O isotope data from the first molars of two
Imperial Roman (1st-3rd c AD) populations

Unfortunately, my Roman data were not as clear-cut as Bethany’s Peruvian data. Except for the one individual who consumed a C4-heavy diet and suffered from porotic hyperostosis, the rest of the diseased individuals are distributed within -13 to -11 permil on the carbon axis, which represents the average Roman diet of mostly C3 resources like wheat and barley. The people with porotic hyperostosis are spread out on the oxygen axis; however, there are none with oxygen isotope values lower than that of Rome. You may recall from older blog posts (like this one) that oxygen isotope values are more negative in cool, dry climates and more positive in hot, humid climates. It’s actually not a surprise, then, that the non-local people with porotic hyperostosis are on the right side of the graph: they were likely from places warmer and more humid than Rome, which means places along the sea and to the south – places that historically had more malaria, for example, than even Rome did. There are few data points on the left side of the graph, but again, I would expect there to be less malaria and fewer parasites in general in cooler, drier climates like the Apennines that were the source of freshwater springs.

This Roman sample size is small, and the data are not perfectly correlated. A simple t-test, though, actually indicated a statistically significant difference between the oxygen isotope means of the group with porotic hyperostosis and the group without it (t=3.06, p<.005), so with more data, I may find a more robust result.  Graphing carbon versus oxygen isotope data has been done for years, but I’d never thought to add porotic hyperostosis as a variable until I heard Bethany’s wonderful talk. This technique has great potential for investigating parasitic disease in ancient Italy, and additional bioarchaeological research - specifically, isotopic analysis - on this front could yield a much stronger argument for the disease ecology of malaria and other parasitic diseases in the peninsula, adding a new dimension to previous osteological studies (e.g., Facchini et al. 2004).

References:

Blom, D., Buikstra, J., Keng, L., Tomczak, P., Shoreman, E., & Stevens-Tuttle, D. (2005). Anemia and childhood mortality: Latitudinal patterning along the coast of pre-Columbian Peru American Journal of Physical Anthropology, 127 (2), 152-169 DOI: 10.1002/ajpa.10431

Facchini, F., Rastelli, E., & Brasili, P. (2004). Cribra orbitalia and cribra cranii in Roman skeletal remains from the Ravenna area and Rimini(I–IV century AD) International Journal of Osteoarchaeology, 14 (2), 126-136 DOI: 10.1002/oa.717

Killgrove, K. 2010. Migration and mobility in Imperial Rome. PhD dissertation, UNC Chapel Hill. [PDF]

... Read more »

  • October 11, 2011
  • 08:20 AM
  • 1,038 views

The Good Behavior of Others Earns You the Right to be Bad

by Eric Horowitz in peer-reviewed by my neurons

Previous research on moral licensing — the idea that doing something that exhibits good morals liberates you to do something morally questionable — has found that it only applies to your own actions. However, a new study by Maryam Kouchaki of the University of Utah demonstrates that this effect holds not just when you have [...]... Read more »

  • October 11, 2011
  • 08:00 AM
  • 1,038 views

Pessimism – It Could Save Your Mind

by Radhika Takru, MA in Brain Blogger

It was only last month that we learned how shared negative opinions and attitudes can result in the formation of speedy and genuine relationships between people. Now there’s research to show that a pessimistic outlook might be better for mental health overall. Before you take this as your cue to walk around with a frown [...]... Read more »

  • October 11, 2011
  • 06:29 AM
  • 1,125 views

How to use augmented reality to provide value

by United Academics in United Academics

Augmented reality enables you to re present parts of the digital world on top of the physical world. However in which way should be use it to provide value?... Read more »

Azuma, R.t. (1997) A survey of augmented reality. . Teleoperators , 6(4), 355-376. info:/

  • October 11, 2011
  • 06:27 AM
  • 1,012 views

Rising Mortality Rates for People with Serious Mental Illness

by The Neurocritic in The Neurocritic

Fig 1 (Hoang et al., 2011). Trend in standardised 365 day all cause mortality ratio for all people discharged from hospital with principal diagnosis of bipolar disorder or schizophrenia.The "mortality gap" is the differential between the mortality rates for the general population and for persons with serious mental illness (schizophrenia and bipolar disorder). A new study from England examined hospital records for psychiatric patients discharged between 1999 and 2006, and determined how many had died within one year (Hoang et al., 2011). The authors expected to see a drop in the mortality gap over time due to government programs:Over the past decade several strategies have been implemented in England and Wales aimed at reducing the mortality gap between people with serious mental illness and the general population, including those to address deliberate self harm and to reduce suicide (7 8 9), to decrease smoking (10 11 12), alcoholism, and drug misuse (13 14) and to deal with other lifestyles associated with increased mortality (15 16). Recent studies have suggested that the rate of suicide has been stabilising among people with mental disorders as a whole (17 18 19 20 21); however, trends in mortality for people with schizophrenia or bipolar disorder remain poorly characterised, particularly the relative contributions of natural and unnatural causes. The United Kingdom government’s recent mental health strategy states that “more people with mental health problems will have good physical health” as one of its objectives, specifically stating that “fewer people with mental health problems will die prematurely” (22). It is therefore timely to review the level of and trends in these recognised inequalities.However, as illustrated in Fig. 1 above, the opposite trend was observed, with increased mortality for those with schizophrenia and bipolar disorder. The standardized mortality ratios show a rise from ~30-60% greater than the general population to about double the population average:For people discharged with schizophrenia, the ratio was 1.6 in 1999 and 2.2 in 2006 (P<0.001 for trend). For bipolar disorder, the ratios were 1.3 in 1999 and 1.9 in 2006 (P=0.06 for trend). Ratios were higher for unnatural than for natural causes. About three quarters of all deaths, however, were certified as natural, and increases in ratios for natural causes, especially circulatory disease and respiratory diseases, were the main components of the increase in all cause mortality. These results are alarming (but not new, unfortunately) and similar to those reported by Chang et al. (2011) - see Improving the Physical Health of People With Serious Mental Illness. In that post, I mentioned the possible role of "second generation" or atypical antipsychotics, which can cause substantial weight gain and hence diabetes, hypertension, cardiovascular problems, high cholesterol, and stroke. To counteract these serious side effects, a regular part of mental health treatment should include programs that promote better physical health: smoking cessation and nutritionists and structured exercise classes in addition to standard psychiatric care and substance abuse treatment. For example, a six month intervention pilot study enrolled 63 overweight participants at psychiatric rehabilitation day programs and showed promising initial results (Daumit et al., 2010).These concerns were mentioned earlier in a systematic review of the literature by Saha et al. (2007), who urged immediate action:“in light of the potential for second-generation antipsychotic medications to further adversely influence mortality rates . . . optimizing the general health of people with schizophrenia warrants urgent attention.”ReferencesChang CK, Hayes RD, Perera G, Broadbent MT, Fernandes AC, Lee WE, Hotopf M, Stewart R. (2011). Life expectancy at birth for people with serious mental illness and other major disorders from a secondary mental health care case register in London. PLoS ONE 6(5):e19590.Hoang, U., Stewart, R., & Goldacre, M. (2011). Mortality after hospital discharge for people with schizophrenia or bipolar disorder: retrospective study of linked English hospital episode statistics, 1999-2006. BMJ, 343:d5422. DOI: 10.1136/bmj.d5422Daumit GL, Dalcin AT, Jerome GJ, Young DR, Charleston J, Crum RM, Anthony C, Hayes JH, McCarron PB, Khaykin E, Appel LJ. (2010). A behavioral weight-loss intervention for persons with serious mental illness in psychiatric rehabilitation centers. Int J Obes (Lond). 35(8):1114-23.Saha S, Chant D, McGrath J (2007). A systematic review of mortality in schizophrenia: is the differential mortality gap worsening over time? Arch Gen Psychiatry 64:1123-31. ~~~~~~~~~~~October 10 was World Mental Health Day, an event designed to raise public awareness of mental health issues:This year the theme is "Investing in mental health". Financial and human resources allocated for mental health are inadequate espec... Read more »

  • October 11, 2011
  • 06:17 AM
  • 1,145 views

Facebook and the unselfish gene

by EE Giorgi in CHIMERAS

So I finally did it. As some of you regulars may have noticed, I put the blog on Facebook. And then I instantly became needy and sent out a bulk of emails begging people to like me. I sent out five and since they're very nice friends of mine, they all liked me. And then I thought, "Well, now, my friends' friends' will like me, and then my friends' friends' friends', and then..."Hmm. That got me thinking. Does it work like with viruses? No, seriously, do "likes" spread like a viral infection in the body? If not, what kind of network do they resemble? Neurons? Random walks? Traffic network? Surely somebody has thought of modeling this -- does anybody know?I really got curious about this. So I logged onto PubMed and did a search under the keyword "Facebook." I got around 200 hits, none of which answered my questions, but I did find a few papers that captured my attention, so I thought I'd list them below.The unselfish gene [1]. Species compete for resources. We've learned in school that natural selection is a competition among the fittest. Philosophers like Hobbes and Machiavelli have stated that humans are essentially selfish, pushing societies to promote self-interest with the use of incentives and punishments. In his review, Dr. Benkler looks at how this line of thinking has changed in the past few years. In fact, we now believe that evolution selects cooperation over competition. The evidence, according to Benkler, doesn't come from evolutionary biology only, but also from sociology, psychology, and economics. And to prove his point, Benkler points to the success of social networks like Facebook, Craigslist, and LinkedIn, which provide emotional, social, and psychological support, gratification, and a great deal of information resources. The sharing of information that goes through the Internet is an indication of cooperation. Indeed, my PubMed search yielded many results on the benefits of Facebook and social networking when it comes to health support groups, health care, and advantages of networking for medical practices. So, I completely agree, except I do find Facebook a little selfish when it comes to... self-promotion. Ahem, yes, I confess I am myself guilty of the crime, since I put my blog in there out of a selfish, egotistical need to have readers... Facebook is smoking [2]. This one sounded intriguing. Does the title imply that Facebook is as addictive as smoking? Or that it's as cancerogenic as smoking? Or maybe, Facebook is smoking on your computer after so much use? Unfortunately, I couldn't find anything besides the title, not even the abstract.Mirror, mirror on my Facebook wall: effects of exposure to Facebook on self-esteem [3]. Does Facebook enhance or diminish self-esteem? My intuition would be that it requires some solid self-esteem to put yourself "out there." The debate is still very much open, however, some of the literature* seems to indicate that Facebook has beneficial effects on self-esteem. So, stop hiding! Find the guts, go out there, and you'll be a better person! (Yes, yes, I am indeed preaching to myself! Again, guilty.)* In my literature search, unfortunately, there were numerous papers I didn't have access to.All of the above is fascinating and interesting, but what about the networking model? I still think a viral infection model might work: you need to re-define parameters such as fitness cost and effective population size. For example, you might send the request to "like you" to, say, 10 friends, but only the ones who will actually click on the like button are the ones who actually "replicate." Say you get 7 likes. Now, all the 7 friends' friends will see the likes, but how many will go ahead and click the like button in turn? That's the effective size population, how many "likes" will actually generate new "likes." In this model there's no immune pressure, but if the effective size is too small, then the infection doesn't take off.Obviously, this is just my speculations, so I did a second PubMed search and this time I typed "Facebook viral," hoping I'd get some insight on whether Facebook "likes" spread like a virus. This is the only entry I got: Using the Internet and social media to promote condom use in Turkey [4]. Not exactly what I meant in my search, but look at the bright side -- another Facebook success story.That's all for today. Short post, I know, but hey, all those refreshing clicks on FB to check the number of likes, it's a lot of work, you know?... Pssst. Hey. If you happen to have a spare second, would you click on the like button up there? ...Okay, those last statements were jokes. Seriously. Just give me a pat in the back and my self-esteem will thrive. Promise.[1] Benkler Y (2011). The unselfish gene. Harvard business review, 89 (7-8) PMID: 21800472[2] Mgweba L, Dlamini S, Kassim J, Planting T, & Smith D (2009). Facebook is smoking. South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde, 99 (11) PMID: 20222194[3] Gonzales AL, & Hancock JT (2011). Mirror, mirror on my Facebook wall: effects of exposure to Facebook on self-esteem. Cyberpsychology, behavior and social networking, 14 (1-2), 79-83 PMID: 21329447[4] Purdy CH (2011). Using the Internet and social media to promote condom use in Turkey. Reproductive health matters, 19 (37), 157-65 PMID: 21555096Photo: last dahlias of the season! Focal length 85mm, F-stop 20, shutter speed 1/50, ISO 100. A special thanks goes to my neighbor who does an amazing job growing these beautiful flowers and then kindly lets me photograph them.... Read more »

Benkler Y. (2011) The unselfish gene. Harvard business review, 89(7-8), 76. PMID: 21800472  

  • October 11, 2011
  • 02:54 AM
  • 729 views

Mental Illness And Creativity Revisited

by Neuroskeptic in Neuroskeptic

A new study offers support for the theory that mental illness is associated with "creative" achievement.The idea that madness is close to creative genius is a popular one. From the nutty professor to the tortured genius, there's no end of sterotypes, and pop culture seemingly offers plenty of examples, from Van Gogh and his ear to Charlie Sheen and his bi-winning.But is it true?A new study says yes. Kyaga et al looked at everyone in Sweden who had been treated as an inpatient for either schizophrenia, bipolar disorder, or depression, between 1973 and 2003. In total that meant about 300,000 people (two thirds of that was depression).They then matched this up with the Swedish national census which asks people their occupation. They looked to see whether the psychiatric cases were more likely to have been employed in a "creative" profession. They defined that as visual artists (photographers, designers, etc.) non-visual artists (musicians, actors, authors) and academics (university teachers).Finally, they pulled up the records on the patients' relatives, to see what their jobs were. This is one of those studies that could only happen in Scandinavia, because only those countries keep such comprehensive ( rather scarily so) info about their citizens.They found that being bipolar, or being a close relative of someone who's bipolar, was associated with having a creative job. For schizophrenia, the picture was more complex: being a schizophrenia inpatient was not linked to being a creative in itself, but being related to someone with schizophrenia was. The effects were fairly modest.For depression (not bipolar, just plain unipolar depression), there was no link at all, or even a slightly lower level.The correlation wasn't driven by differences in IQ (yes, they had data on that too, for males, thanks to military service records.) Creative types had higher IQs on average while psych inpatients had slightly lower IQs than others. So correcting for IQ made the associations even stronger.So it looks as though being bipolar, at any rate, is linked to creativity, and so is having bipolar and schizophrenia in the family - if you believe these findings. Should we?This study was huge and the data are, on the face of it, very comprehensive. However, it turns out that many people didn't state their occupation, especially the patients. Only 45% of people with schizophrenia gave a valid answer, compared to 75% of the bipolar and depressed. In the controls, it was about 80%.That's a serious issue. The authors did try to get around this by looking at the siblings of the patients with missing data. For schizophrenia, siblings of missing data schizophrenics were more creative than for the ones with full data, and for bipolar there was no difference. So the effects are not due to nonreporting of non-creative jobs.Another possible confound is family background and environment. Indeed, the fact that people with bipolar were no more likely to be in a creative job than their relatives who weren't bipolar (or, at least, never received inpatient treatment) rather supports this view. Maybe the relatives shared genes with the patients meaning that their creativity was associated with bipolar, but we can't know that.One reassuring piece of evidence against the idea that these results were driven by a general correlation between psychiatric hospitalization and "middle class professions" is that there was no association with the "non-creative" job of accountancy and auditing (sorry accountants and auditors).Overall, while this is an interesting study, and while I find the proposed link between mental illness and creativity plausible, we need more detailed research to ensure that the correlation isn't just a reflection of socioeconomic factors.Kyaga, S., Lichtenstein, P., Boman, M., Hultman, C., Langstrom, N. Landen, M. (2011). Creativity and mental disorder: family study of 300 000 people with severe mental disorder The British Journal of Psychiatry DOI: 10.1192/bjp.bp.110.085316... Read more »

Kyaga, S., Lichtenstein, P., Boman, M., Hultman, C., Langstrom, N., & Landen, M. (2011) Creativity and mental disorder: family study of 300 000 people with severe mental disorder. The British Journal of Psychiatry. DOI: 10.1192/bjp.bp.110.085316  

  • October 11, 2011
  • 01:16 AM
  • 1,395 views

Baby Pains

by Nsikan Akpan in That's Basic Science

A neuroimaging study tries to define when pain perception crops up in infants.... Read more »

  • October 11, 2011
  • 12:05 AM
  • 544 views

Variation: a blessing and a curse

by zacharoo in Lawn Chair Anthropology

Trying to start on finishing my dissertation, I'm thinking about the issue dental development and how it relates to skeletal growth. Specifically I'm trying to decide whether I want to analyze my human and Australopithecus robustus samples based on estimates of "dental age," or if I want to be a bit more cavalier and divide the sample into rougher age categories.To avoid copyright issues, here's a crappy picture I drew a few years ago, of the youngest A. robustus jaws. The youngest, "SK 438" is erupting its last baby tooth (bottom right), while the others have their full set of baby teeth, and none of them has its first adult tooth yet. I don't think I can estimate ages accurately enough to capture the true chronological difference between SK 438 and the rest. Would I be better off just dividing the group into "younger" (SK 438) and "older" (the rest) infants, or even lumping them all together as simply "infants"?On the one hand, I could assign individuals a chronological age based on a modern referent of known age, at similar stages of dental development. This could allow me to get more fine-scale glimpses into patterns of growth in my samples, but that's assuming I've accurately estimated their ages. Individuals vary in the ages and sizes at which their teeth erupt; a person's first molar, for example, may erupt at anywhere from 4-8 years of age. How can I estimate an individual's age in light of such variation? And what if I'm as poor a judge of ages as Dennis Duffy?! Conceivably I could program my analysis to account for error estimation (which in itself could be educational and interesting, but is it worth the trouble?), but this would also add a further source of uncertainty. And it's like Dwight Schrute said (Michael Scott said), "K-I-S-S: keep it simple, stupid. Great advice, hurts my feelings every time."On the other hand, I could divide my sample into coarse age categories - say, putting specimens who've attained a given level of dental development in the same group, such as 'infant, child, juvenile, adolescent, and young adult.' This method loses the temporal resolution of the first method, but also avoids the possible errors of assigning strict ages I'm pretty sure I would not infer accurately. But, tooth development does not show a clean 1-to-1 relationship with other systems in the body, such as hormonal axes or the bony skeleton. It's uncertain how accurately kids can be put in any of the above categories (based on general life history variables; Bogin 1999) based on dental development.Choices, choices.Variation is a problem for biologists. The theory of evolution was conceived as a way to explain the conundrum of why there is such remarkable variation in the forms of life that Earth is lucky to have harbored. The problem of within-species variation in the relative timing of skeletal and dental development isn't just a bug-bear for paleoanthropologists. It's important to medical doctors and pathologists investigating genetically-based developmental disorders, and to epidemiologists looking at aspects of population health, such as the prevalence of growth stunting. It's also important for forensics specialists who need to use biological clues about the age and identity of crime victims and defendants. I mean, how else would we know whether Jon Voigt bit Kramer and this pencil?The silver lining, I suppose, on this storm-cloud of biological of variation is that without variation there cannot be evolution. And stasis is boring. If nothing changed since the Cambrian, none of us would be here today. We'd probably be some gross stupid monstrous thing, like this Hallucigenia to the right. It's the quirks and weird variants that arise randomly, that make evolution possible. If individuals all developed exactly the same, then all organisms through all time would be the exact same, and probably all would have gone extinct as they succumbed to some sinister fate, no new variants would have arisen that may have been able to survive the devastation.So variation is a blessing and a curse. Individual and population variation make it difficult to state norms such as what is "average" or "healthy," and nothing to be concerned about. Variation is also the magic ingredient of adaptation, without which Life could not survive the randomness inherent in any environment.Things I citedBogin, B. (1999). Evolutionary perspective on human growth Annual Review of Anthropology, 28 (1), 109-153 DOI: 10.1146/annurev.anthro.28.1.109Also 30 Rock, The Office and Seinfeld. Well done, NBC.... Read more »

Bogin, B. (1999) Evolutionary perspective on human growth. Annual Review of Anthropology, 28(1), 109-153. DOI: 10.1146/annurev.anthro.28.1.109  

  • October 10, 2011
  • 10:00 PM
  • 769 views

A history of music cognition?

by Henkjan Honing in Music Matters

One of the pioneers in the field that would come to be called music cognition was H. Christopher Longuet-Higgins (1923-2004). Not only was Longuet-Higgins one of the founders of the cognitive sciences (he coined the term in 1973), but as early as 1971 he formulated, together with Mark Steedman, the first computer model of musical perception. That early work was followed in 1976 with a full-fledged alternative in the journal Nature, seven years earlier than the more widely known, but, according to Longuet-Higgins, less precisely formulated, Generative Theory of Tonal Music of Lerdahl and Jackendoff.... Read more »

Longuet-Higgins, C. (1983) All in theory — the analysis of music. Nature, 304(5921), 93-93. DOI: 10.1038/304093a0  

Longuet-Higgins, H. (1976) Perception of melodies. Nature, 263(5579), 646-653. DOI: 10.1038/263646a0  

Honing, H. (2011) The illiterate Listener. On music cognition, musicality and methodology. Amsterdam University Press. info:other

  • October 10, 2011
  • 06:45 PM
  • 815 views

Prostate Cancer Screening – the debate continues

by Pieter Droppert in Biotech Strategy Blog

The recent announcement from the United States Preventative Services Task Force (USPSTF) on prostate cancer screening has stimulated a lot of debate.  ”Dr Len’s Cancer Blog” from the American Cancer Society has a thoughtful piece about the “to screen or … Continue reading →... Read more »

Alemozaffar, M., Regan, M., Cooperberg, M., Wei, J., Michalski, J., Sandler, H., Hembroff, L., Sadetsky, N., Saigal, C., Litwin, M.... (2011) Prediction of Erectile Function Following Treatment for Prostate Cancer. JAMA: The Journal of the American Medical Association, 306(11), 1205-1214. DOI: 10.1001/jama.2011.1333  

Roger Chou, MD, Jennifer M. Croswell, MD, MPH, Tracy Dana, MLS, Christina Bougatsos, BS, Ian Blazina, MPH, Rongwei Fu, PhD, Ken Gleitsmann, MD, MPH, Helen C. Koenig, MD, MPH, Clarence Lam, MD, MPH, Ashley Maltz, MD, MPH.... (2011) Screening for Prostate Cancer: A Review of the Evidence for the U.S. Preventive Services Task Force. Annals of Internal Medicine, E-375(October 7). info:/

  • October 10, 2011
  • 06:43 PM
  • 722 views

Birth control and HIV risk: What women AND men should know

by NerdyOne in Try Nerdy

Until now, complaints about hormonal birth control – mood swings, nausea, breast tenderness – have almost exclusively come from the woman taking the hormones. However, recent findings about one popular type of birth control should have women and their intimate partners equally concerned. The issue is with a potentially considerable increased risk of HIV infection for both the woman and her partner, and the new research even has some HIV/AIDS scientists saying “I told you so.”... Read more »

Heffron R, Donnell D, Rees H, Celum C, Mugo N, Were E, de Bruyn G, Nakku-Joloba E, Ngure K, Kiarie J.... (2011) Use of hormonal contraceptives and risk of HIV-1 transmission: a prospective cohort study. The Lancet infectious diseases. PMID: 21975269  

Marx PA, Spira AI, Gettie A, Dailey PJ, Veazey RS, Lackner AA, Mahoney CJ, Miller CJ, Claypool LE, Ho DD.... (1996) Progesterone implants enhance SIV vaginal transmission and early virus load. Nature medicine, 2(10), 1084-9. PMID: 8837605  

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