SciBlogs

Is Acupuncture Worth a Punctured Lung? or Does the Risk Out Weigh the Benefit? Darcy Cowan Aug 16

11 Comments

Friday’s issue of The New Zealand Medical Journal includes a case report of pneumothrorax in a recipient of acupuncture. For the interested layperson out there a pneumothorax in the collection of air in the space between the lung and chest wall leading in extreme cases to cardiac arrest. Acupuncture can result in pneumothorax when the needle is inserted into the lung tissue while the patient is breathing leading to the laceration of the lung and air being forced out of the lung and into the pleural cavity1. Mmm-mmm, gimmie some of that lung collapsing goodness.

Now lest I give the impression that complications from acupuncture use are common I will hasten to add that they are not. One paper estimates the rate of serious adverse events at approximately 1 per 20,ooo patients2. Though if we look at the rates of acupuncture use in the United States as an example, as of about 2007 approximately 1% of the population reported using acupuncture in the previous 12 months3. This translates to about 155 serious adverse effects per year. Another study found over 2% of patients reported adverse reactions that required treatment4, commonly for bleeding or pain. Multiply these figures by the likely worldwide numbers of people receiving acupuncture.

Lets compare this with the conventional medical field, the drug Terfenadine marketed under the trade name Seldane (Teldane here in NZ) was removed from the market in the US due to increased risk of cardiac arrhythmia when used in conjunction with certain other drugs. This expressed itself as a risk of 0.04 – 0.08 per million “defined daily doses”5. Once a replacement drug came on the market Terfenadine was taken off.

Pneumothorax as a complication from acupuncture is  rare even in this subgroup. More common is infection. As I’ve noted before6, the underlying theory of acupuncture is the manipulation of life energies (Qi or Chi), blockages or imbalances in which are the cause of disease. If such is the case then why should the treating physician7 bother with proper antiseptic technique? I suspect that most modern practitioners are however not so far down the rabbit-hole that they have thrown away germ theory completely, at least the outward practical side involved in cleaning and sterilising implements. Which is why even infections are still relatively infrequent.

I would like to point out however that given the implausibility of the treatment basis, coupled with the fact that most large well designed studies find no benefit beyond placebo does make the existence of any complications ethically troubling. If your treament is no more than an elaborate placebo, are you willing to suffer adverse effects because of it? As reported by Dr Novella of Science Based Medicine8, a recent review of acupuncture admitted that sham (placebo) acupuncture was as good a “real” acupuncture.

Lets delve into the definition of “sham” acupuncture a little more to give the proper context to this revelation. Whereas “real” acupuncture depends on the proper insertion of the needles in specific meridian points on the body sham acupuncture can be considered to be either the placement of needles into non-meridian points, or the use of implements that feel like needles to the patients but do not pierce the skin like toothpicks9. This indicates that it doesn’t matter where you stick the needles and it doesn’t even matter if you stick the needles. How then can we conclude that acupuncture works if you don’t need to perform the two defining characteristics of acupuncture?

Given this background I find it difficult to imagine why acupuncture continues to be recommended despite convincing evidence of efficacy and indisputable evidence of harm. All medical interventions carry some element of risk, this is then weighed against the potential for benefit. However when there is no benefit any amount of risk must make that equation lopsided with regard to harm. With that in mind, if you are attracted to acupuncture as a therapy let me recommend sham acupuncture as the way to go. All the placebo-y goodness of real acupuncture without the potential for the nasty drawbacks of infection, bleeding, pain or even pneumothorax.

Further reading:

Type “Acupuncture” and “Infection” or “Pneumothorax” into Pubmed as key words and you will find a variety of papers, a selection of which are below:

Acupuncture induced pneumothorax:a case report (not the report mentioned in the post)

Editorial:Acupuncture transmitted infections

Cutaneous Mycobacterium haemophilum infection in a kidney transplant recipient after acupuncture treatment.

Acupuncture needle-associated prosthetic knee infection after total knee arthroplasty

Footnotes:

1. Clinical analysis on 38 cases of pneumothorax induced by acupuncture or acupoint injection

2. A cumulative review of the range and incidence of significant adverse events associated with acupuncture

3. http://nccam.nih.gov/health/acupuncture/introduction.htm

4. Safety of acupuncture: results of a prospective observational study with 229,230 patients and introduction of a medical information and consent form.

5. Detection and reporting of drug-induced proarrhythmias: room for improvement

6. Scepticon: Acupuncture

7. And here I use the term loosely.

8.Acupuncture Pseudoscience in the New England Journal of Medicine

9. I kid you not, here are a couple of the studies:
Description and Validation of a Noninvasive Placebo Acupuncture Procedure
A randomized trial comparing acupuncture, simulated acupuncture, and usual care for chronic low back pain

Related articles by Zemanta
Enhanced by Zemanta

Filed under: Alternative medicine, Medicine, Questionable Techniques, Sciblogs, skepticism Tagged: Acupuncture, Acupuncture and Chinese Medicine, alternative, Alternative medicine, altmed, collapsed lung, complementary and alternative medicine, health, Health and Medicine, Medicine, New England Journal of Medicine, pneumothorax, Science

Print This Post Print This Post

Round Numbers are Over Rated: Celebrating 191 Posts Darcy Cowan Aug 11

No Comments

I’ve long found the fascination with celebrating milestones that have no intrinsic worth to be somewhat puzzling, why should we make more effort for birthdays falling on a multiple of ten than those that come just before or after? There is nothing about the number itself that makes such a milestone special.

In this vein I decided that rather than trumpet my 200th post I would pick a number that is more interesting (and closer). So, welcome to my 191st blog entry. Compared to some of my more prolific colleagues on Sciblogs and in the blogosphere 191 posts over a period of almost 3yrs is practically laughable but you work with what you’ve got.

So, why 191? Well according to the Oracle of Wikipedia this number has many special features.

191 is an odious number, apparently numbers can be categorised as either odious or evil. This is a reference to it’s properties when converted into binary. As you are likely aware the binary system represents numbers as strings of zeroes and ones. For example the number six can be represented as 110, the number 191 is represented by the string 10111111. A number is evil if there are an even number of 1s in the string (like number 6) and odious if the number of 1s is odd. Those mathematicians are a funny bunch. (play with binary here)

The number is a prime, and apparently there are a large number of prime flavours and this one has quite a few. It is a palindromic prime number, and not only that it is the smallest such prime that you also get a palindromic prime number when you sum the individual numbers.

191 is a Chen prime, which mean if you add 2 to it you also get a prime (or the product of two primes, but in this case a prime).

It is also the first number of a prime quadruplet, so that in addition to adding 2 and getting a prime as above you can also add 6 and 8 and still get primes as well.

Sophie Germain prime numbers occur when you can multiply a prime number by 2, add 1 and get another prime. Guess what, 191 is one of these too.

Those were the less esoteric prime properties that 191 displays. Aren’t you glad I didn’t keep going?

191 is also a Thabit number, or a number that can be arrived at using the formula 3 x 2n – 1.  ie run this formula and plug values into the exponent position n and you will get a series of numbers of which 191 is one (n=6 BTW). This formula can be used to generate a sort of number called Amicable numbers, but beyond that I have no idea why this would matter.

Finally 191 is the atomic number of a theoretical element called Unununium, sounds like the start of a sneeze.

There you go, 191 is way more interesting than a boring number like 200. A far better choice for celebration.

Still on the topic of numbers here’s a visually stunning video looking at numbers in nature, specifically the Fibonacci sequence.

Youtube Direct

Enhanced by Zemanta

Filed under: Psychological, Sciblogs, Science Tagged: Math, mathematics, Number Theory, Prime number, Science

Print This Post Print This Post

Delayed Gratification = Success? Darcy Cowan Aug 10

3 Comments

Today we are going to step into the time machine and go back 21 years to 1989. It was in this year that the study to become known as the “Marshmallow experiment” was published. Performed by Walter Mischel at Stanford University this experiment showed an amazing thing, that testing a child’s self-control at 4yrs could predict academic success later in life.

The numerous experiments actually entailed in this study started with the same basic premise. Children were told that they could obtain a small reward immediately or could hold out for a more valuable reward later. The rewards were carefully calibrated to produce conflict in the child over whether to go for the immediate reward or wait for the larger reward (eg one marshmallow vs two, hence the name of the experiment). The experimenter would then leave the child alone and return a short (although not for the child) time later, typically about 15 minutes. The child could ring a bell at any time to recall the experimenter and receive their lesser reward.

Over a series of experiments the researchers examined what strategies were most effective at helping the child to delay their own gratification the longest. In some situations the rewards were fully visible, allowing the children to see only the immediate reward, only the delayed reward or both. In others the rewards were present in the room but hidden. We might find it obvious but those children who could see the rewards could not wait as long as those that had the rewards hidden.

It’s important to remember here that while some of the conclusions of the study seem obvious in hindsight (and possibly to anyone with young children) previous theories of the ability to delay gratification have considered the ability to conceptualise rewards instrumental to being able to to inhibit impulsivity. To explore this hypothesis then the researchers primed the children with various thoughts prior to the experiments, either by encouraging the children to think about the rewards or by giving them other fun things to think about.

The findings showed that how the child thought about the rewards significantly impacted how long they waited, whether or not the rewards was sitting in full display in front of them. Those children that were distracted by the fun thoughts could hold out longer than those who ere primed to think about the rewards.

To examine this further children where then primed to think about the rewards in different ways. Those who were told to think about what were termed “arousing” properties of the rewards, for example the texture and taste of a food reward, had much more difficulty delaying than those who were directed to think about the abstract qualities of the reward. Indeed, those children who were told to imagine real rewards were only pictures of the objects did much better than children who were told to imagine that pictures of the rewards were real.

One of the best strategies found by the study was for the child to imagine the arousing properties of a different food to the one they would get as a reward, eg thinking about the taste of pretzels while waiting for marshmallows.

So far so good, here’s where the real surprising aspect comes, in a follow-up to these experiments children from the original studies were then looked at more than ten years later to see if the ability to delay self gratification had effects later in life. They authors predicted that differences in the ability of children to delay when they had been given no strategies to help them (eg hiding the rewards) would perform better later in life than those who had the rewards removed from sight. This prediction turned out to be upheld, those students who could had been able to delay their own satisfaction without external help had higher test scores and were described by their parents as, to quote the study:

“more verbally fluent and able to express ideas; they used and responded to reason, were attentive and able to concentrate, to plan, and to think ahead, and were competent and skillful. Likewise they were perceived as able to cope and deal with stress more maturely and seemed more self assured.”

The results of this study seem to imply that those individuals who are able to spontaneously generate strategies to aid them in planing for and achieving future rewards are better equipped to deal with life. Hhmm, when I put it that way it seems obvious, I have to point out though that it is only through experiments and observations such as this that these conclusions become obvious. Without the ability to identify the ability of children to employ coping strategies themselves there would have been no basis upon which to predict this outcome.

Congratulations, you’ve made it to the end of this post, here’s a reward. An amusing video featuring a re-creation of the original experiment showing children in the sweet agony of indecision.

Youtube – Marshmallow Experiment

–
Mischel, W., Shoda, Y., & Rodriguez, M. (1989). Delay of gratification in children Science, 244 (4907), 933-938 DOI: 10.1126/science.2658056

Enhanced by Zemanta

Filed under: Psychological, Sciblogs, Science Tagged: Child, Educational Resources, Experiment, health, psychology, Science, Science and Society, Social Sciences, Stanford University, Walter Mischel

Print This Post Print This Post

Pharmacy Customers Perception of Complementary and Alternative Medicine in Pharmacies Darcy Cowan Aug 05

No Comments

Going through the papers cluttering my inbox I found this survey of Australian pharmacy customers relating to their use of CAM and their impressions of how pharmacists should approach the subject.

Regular readers of Sciblogs may remember a kerfuffle earlier in the year regarding the sale of homeopathic remedies in pharmacies, I and others were uncomfortable with these items being sold in pharmacies to begin with. Fortunately, when surveyed homeopathy didn’t make it into the top ten modalities used in the last 12 months, though 3% noted that they had seen a homeopath.

This survey was published in BioMed Central‘s journal of Complementary and Alternative Medicine. I might point out that I disagree with the authors views of Complementary Medicine (CM) but I agree with many of the conclusions of the survey, though I suspect for different reasons.

The survey included data from 1,221 respondents from 54 pharmacies that cover both rural and urban areas. Beyond that the methods aren’t particularly interesting, people filled out forms.

Findings of the survey showed that a significant number of pharmacy customers think that it is important for pharmacists to be knowledgeable about CM and to know about their customer’s CM use. I would agree with this, pharmacists should be aware of how CM is marketed and of the claims made on order to give customers appropriate advice on effectiveness. Another result of the survey that helps with this point is that almost 70% of respondents agreed that they trust their pharmacist’s advice regarding CM. This reveals an excellent opportunity for education of the public regarding these modalities.

In addition many of the respondent felt comfortable telling pharmacist about their CM use whereas previous research has shown this not to be the case for patients of other medical practitioners. Again this is an opportunity for pharmacists to assess the safety of CM modalities their patients are using, especial in conjunction with other treatments (this was also a conclusion of the survey).

That said, the survey also revealed that many customers rely on family and friends as information sources. This accords with with existing research on the importance of personal anecdote in making decisions. Next most popular were medical doctors (not bad) and in third place (disturbingly) was the media. Pharmacists were in 6th place after naturopaths and pharmacy assistants. While far down on the list pharmacists still rank and one of the important sources of information and should not be under estimated.

One of the questions that I disagree with the majority of respondents on is regarding the inclusion of natural medicine practitioners in pharmacy practices. To me this is inviting abuse of the pharmacist’s position of authority, it might even undermine some customers trust of the institution (I’d certainly think twice about any pharmacy that did this). At the very least it may allow pharmacists to divest themselves of the responsibility to actually learn about the alternative products they may be selling.

In conclusion, I consider the results of this survey important to keep in mind when considering the role of pharmacists in the field of CM. Pharmacists are in a somewhat unique position to educate the public regarding CM as a consequence of the level of trust afforded to them by customers. It also reveals that pharmacies are vulnerable to particular abuse for exactly the same reason, products sold in pharmacies are lent an aura of respectability by association.

It behoves pharmacists to take seriously the responsibility to be current on the debate around the safety and efficacy of CM modalities and be able to confidently relay this information to customers. No longer should pharmacists sit on the sidelines while irrationality invades their practice, hiding behind public demand as an excuse for not taking a stand for science based therapies.

–
Braun, L., Tiralongo, E., Wilkinson, J., Spitzer, O., Bailey, M., Poole, S., & Dooley, M. (2010). Perceptions, use and attitudes of pharmacy customers on complementary medicines and pharmacy practice BMC Complementary and Alternative Medicine, 10 (1) DOI: 10.1186/1472-6882-10-38

Related articles by Zemanta
Enhanced by Zemanta

Filed under: Alternative medicine, Medicine, Psychological, Sciblogs, skepticism Tagged: Alternative medicine, BioMed Central, health, Health and Medicine, Homeopathy, Medicine, naturopathy, Pharmacy, Physician

Print This Post Print This Post

Randomness and Clustering: Is the Number of Twins in Timaru a Mystery? Darcy Cowan Aug 04

4 Comments

If you saw 3 News last night you might have caught the story about the bumper crop of twins born this year. The prologue to the story gave the impression of a mystery with words to the effect of  “Experts are at a loss to explain it”, I personally think this was a sloppy attempt to generate some “Experts are baffled” buzz around an essential pointless story that just filled up a slow news day.

Stuff also covered the story but without the mystery aspect, good thing because the stats given at the end of the piece kind of belie that approach.

“The previous year was another big year for twins with ten sets born out of 620 babies. In 2005 and 2006 there were 542 babies born, including six sets of twins. In 2004 and 2005 only two sets of twins were found among the 571 babies born and in the 2003 and 2004 year, there were sevens sets of twins and one set of triplets in the 557 babies born.”

So in other words the number goes up and down every year and this year just happened to be a cluster of births higher than average. Boring.

What’s the deal with randomness though and why are we so poor at recognising it? We tend to think of random events or locations as those that are approximately evenly distributed in time or space. This view of randomness however gives a false impression of what it means to be truly random.

Randomness is more a measure of unpredictability than it is of aesthetic impression. There are different ways of defining this property but one approach is to apply the criteria of an algorithm. An algorithm is essentially a series of instructions, the more instructions, the more complicated the algorithm. One such might be “1. from an initial number add 5, 2. repeat step 1.”. This would be an algorithmic representation of a sequence of numbers at regular increments of 5 eg 1,6,11,16,21.

Nothing random about that, the key here though would be that a sequence of really random numbers wouldn’t be able to be represented by an algorithm that was less complicated than the sequence itself, ie it would be it’s own algorithm and would not be able to be compressed any further.

What has this got to do with groups of twins? Well, if events such as the birth of twins are actually random (simplifying the world somewhat) then we would expect to see variations in the number of births in any one place. Based on this assumption we can look back at previous numbers to see whether this year is within the range we would expect.

Using the figures from the story and removing this year’s number and the year that only 2 twins were born as a possible outlier I get a range of between 0.5% and 2% of births being twins, with a high probability that normal variation will fall in this range. The percentage of twin births this year is 1.8%, high but apparently normal.

Now the sample size here is very small so I wouldn’t put too much trust in it but it is indicative that there is nothing really out of the ordinary going on here. According to the NZ Multiple Birth Association there were 900 multiple births last year in NZ (incl. triplets) this is about 1.4% of the 63,000 live births in NZ last year. So rough and ready these numbers may be but they aren’t too far off the mark, some places will be higher than average and others lower.

So when several rare(ish) events happen at the same time or place, consider; is this really unusual? What would we expect if it was just random?

Related articles by Zemanta
Enhanced by Zemanta

Filed under: Psychological, Sciblogs, Science, skepticism, Uncategorized Tagged: Multiple birth, New Zealand, Probability, randomness, Science

Print This Post Print This Post

Is there a Biochemical Marker for Suicide? Darcy Cowan Jul 26

No Comments

Suicide is a sensitive subject, by it’s very nature it seems we are obliged to treat it with kid gloves. In public it is virtually taboo to even mention suicide, in news media euphemisms are employed in order to avoid explicit use of the “S” word. Attitudes are beginning to change, with more vocal discussion about mental illness and euthanasia in both this country and abroad.

One of the key issues is whether a person is capable of deciding to end their own life or if such a decision automatically excludes them from the definition of mentally competent. I found myself pondering these things as I attempted to come up with a way to introduce the research that is ostensibly the focus of this post.

Regardless of your moral position on the subject of suicide I think we can mostly agree that identifying persons at risk of suicidal tendencies would be helpful in alleviating the pain that accompanies this choice (if indeed it can be described as such). This is where a paper published recently in PLoSONE comes in. The study authors point out in the introduction that previous work has been able to correlate increased blood brain barrier permeability with suicide in patients with prior mental disorder.

Perhaps at this point I should take a step back and provide a little more information on what we are discussing here. The blood brain barrier (BBB) is a system of control that restricts what can and cannot pass between the normal circulatory system and the cerebrospinal fluid (CSF) or the bath that your brain sits in.

In practical terms this means tight connections between the cells of your capillaries to prevent leaks and transport systems to get nutrients back and forth across the barrier. Imagine a dam made of tightly packed stones with channels for the controlled movement of water and you have the basic idea.

Anyway, if the BBB becomes more permeable then it is reasonable to suppose that proteins found in the CSF would be found in higher concentrations in the blood than would normally be expected. If the permeability of the BBB is also correlated with suicidal behaviour then the presence of these proteins become an indirect test for suicidal tendencies.

This is the hypothesis that the research then tested, ie. does the presence of proteins in the blood normally found in the CFS correlate with suicidal tendencies? This study looked specifically at a protein known as S100B, primarily associated with certain cells in the brain and spinal cord. Included in the study were 64 adolescents (average age ~14.5 yrs) diagnosed with either psychosis or mood disorders and 20 healthy control subjects.

The subjects were evaluated and their suicidality was ranked from 1-7*, Blood tests then determined the levels of S100B. The findings showed that levels of S100B significantly correlated with suicidality in the subjects. Looking at the data accompanying the study it seems there is a wide margin of uncertainty on these readings. With a relatively small number of subjects I’m not particularly surprised by this but I would be looking to see more investigation into this approach to determine it’s reliability.

Obviously this technique will not replace psychiatric evaluation, it may prove useful though in helping identify those that are most at risk of suicidal behaviour. If I may return to the broader issues I raised at the start of this post, I would also find it interesting if this test (once extensively validated) could separate those who wish to end their lives due to illness into groups consisting of those with suicidal thoughts because of mood disorders and those who are otherwise of sound mind.

Something to think about.
–

* 1-no suicidality is present, 2-very mild (thoughts when angry), 3-mild (occasional thoughts), 4-moderate (thoughts present in the last week), 5-moderately-severe (recurrent thoughts present almost daily), 6-severe (current suicidal plan), 7-extremely severe (patient attempted suicide within the last week)

–

Falcone T, Fazio V, Lee C, Simon B, Franco K, Marchi N, & Janigro D (2010). Serum S100B: a potential biomarker for suicidality in adolescents? PloS one, 5 (6) PMID: 20559426

Related articles by Zemanta
Enhanced by Zemanta

Filed under: Medicine, Psychological, Sciblogs, Science Tagged: Death, Disorders, End-of-Life, Euthanasia, health, Health and Medicine, Mental disorder, Mental health, Research, Science, Science and Society, Suicide

Print This Post Print This Post

The Risky Business of Hunger Darcy Cowan Jul 16

No Comments

ResearchBlogging.org

We like to think of ourselves as rational actors when it comes to making decisions, we take in information, process it and choose the path that we think will lead to a desirable outcome (if we aren’t deep-seated masochists I suppose). Regular readers of this blog and others that espouse a sceptical viewpoint will know that this isn’t really the case. We are influenced by a large number of factors from implicit biases, to environmental factors, and errors of thinking. The hope is that if we are aware of these factors we can go some way toward mitigating their effects and making choices that are both rational and lead to improving our lives.

Well, here’s another one for you. You may have guessed by the title of this post that it involves food and risk taking behaviour. A paper published last month in PLoS ONE out of the University College London looked at how hunger and food intake affected choices that had a monetary reward. The actual experimental design ran something like this, subjects fasted for 14 hours they then performed tasks that in effect were an idealised lottery, the tasks were performed before, directly after and an hour after a standardised meal. Over this time the subjects also had blood samples taken to measure hormones that correlate with hunger and energy reserves.

The task subjects had to perform consisted of choosing one of a pair of “lotteries” where there was a 25% chance of receiving one of four monetary amounts. Each pairing was designed so that there was always a difference in risk between the two  (see the picture it’s hard to explain).

Paired Lottery doi:10.1371/journal.pone.0011090.g002

How the subjects performed on the tasks was measured to determine the amount of risk aversion. In other words, humans have a tendency to normally prefer less risky choices. The effect of of hunger and especially immediate satiation (right after eating the meal) is to decrease this risk aversion and to make the subjects more risk neutral.

This way of referring to the subject matter is a little counter intuitive and can take a bit of getting used to, the bottom line is that the researchers looked for the point at which the subjects were equally likely to choose the “safe” bet which promised an certain average reward, and a “risky” bet that may lead to a higher average pay off but a lower chance of receiving it. Thus risk aversion has been reduced. By varying the reward amounts the researchers can measure the degree of risk aversion in each subject as the trial proceeds.

Actually the correlation is more complex than I would have thought, not only is the fact that calories are received taken into account but also the amount of calories. It seems that the size of the meal (in terms of calorific intake) is assessed to determine if it meets the rate of food intake required to meet baseline energy requirements. If it does risk aversion is increased (less risky behaviour) if not the risk aversion is decreased.

In hormonal terms this meant that a greater drop in the hormone associated with hunger was correlated with greater risk aversion but a smaller drop meant an increase in risk taking behaviour. The study authors also note that the adiposity of an individual (eg higher BMI) correlated with the size of the hormonal decrease after eating with higher BMI subjects experiencing a smaller drop and a corresponding greater increase in risk taking behaviour.

In effect we not only look at the reward in terms of the gain we will receive compared to our external resources (cash in the bank, say) but also in relation to our internal resources (metabolic requirements for example). This makes sense if we consider that for most of our history true advantage was not measured in abstract accumulation of “wealth” which we would recognise today but in available energy, including that within our bodies. That’s just a speculation of course, I’m no expert in this area.

What is the take home message of this research then? Well first off we should be careful to realise that risk taking behaviour is not limited to single domains in our lives. If you take away from this that only financial decisions are affected then that is too narrow an interpretation. In the final analysis though, no matter our eating habits or body size, we should endeavour to think over important decisions carefully and be aware of the changeable nature of our biology and it’s effects on our thinking.

–

Symmonds M, Emmanuel JJ, Drew ME, Batterham RL, & Dolan RJ (2010). Metabolic state alters economic decision making under risk in humans. PloS one, 5 (6) PMID: 20585383

Related articles by Zemanta
Enhanced by Zemanta

Filed under: Psychological, Sciblogs, Science, skepticism Tagged: Biology, Business, Decision making, Eating, Research, Risk, Risk Management, Science, Science and Society, University College London

Print This Post Print This Post

Miracles: What Do We Mean? Darcy Cowan Jul 14

No Comments

Have you ever described an event as miraculous? Perhaps it was a near-miss accident, recovery from an illness or some other fortuitous moment in your life. Did you stop to consider what you meant by that description or did or roll off your tongue like so many other cultural conventions, without a second thought?

One of the reasons I write this blog1 is to allow people the opportunity to examine the world and themselves in more detail and more reflectively than they might ordinarily be inclined to do. In this I have largely attempted to do so using science directly, by showing research that reveals facts about ourselves and the world around us that are not necessarily intuitively obvious (such as biases in our reasoning).

I thought I would deviate from the strictly scientific today to discuss miracles, especially the depiction of miracles in the media and what is really meant when we resort to the designation of “miracle” in describing events.

Recently I have started reading popular philosophy books, trying to be a well rounded person or something, or possibly just so I sound intelligent at parties2. I may delve a little bit into philosophy here but hopefully can keep it light enough that you won’t even notice.

One of the books on my reading list brought up the concept of miracles and attempted to outline the different definitions that are attached to this word3. This sparked in me a thought about how the word is used by those around me, in the general population these multiple versions of the meaning get seem to get merged into an amorphous description that verges on meaninglessness.

Many of the definitions of the word that I could find invoked some sort of supernatural component, in particular the assertion that such an event contravenes the laws of nature. By this criteria I have never witnessed, nor seen credible reports of a single miracle, yet I hear the word used all the time4. How can we reconcile how the word is defined and how it is used?

Let us note one instance of the (over)use of this word, last year when an aeroplane crash landed in the Hudson river after hitting a flock of birds soon after take off the event was labelled a miracle. Currently no fewer than ten news stories with the word “miracle” in the title are listed in the Wikipedia article about this event and I suspect there are many more not mentioned. This seems to be the type of event that attracts exclamations of “Miracle” yet if we delve into the details there is no point at which we can reliably determine that the laws of nature have been suspended or otherwise altered to allow the final outcome.

If we are committed to the definition that for a miracle to have occurred the laws of nature must be violated then this event does not qualify.

Of the multiple meanings that I mentioned above it would appear the most frequently used makes the word “miracle” synonymous with “unlikely coincidence”. This though is insufficient to describe what most people would consider to be miracles as it ignores whether or not an event has any beneficial consequences, so lets add that requirement into our ad hoc definition.

The trouble with this definition is that it leaves us unable to determine what we might term “True Miracles” from merely random (beneficial) occurrences. Especially in as much as, like the Hudson river crash above, said miracles have no religious significance5. This pre-supposes however that we would wish to make such a distinction, if (as I suspect) our use of the word actually no-longer assumes the intervention of supernatural forces then our definition of “True Miracles” becomes superfluous, no different than what we might consider a regular miracle.

In this case the word simply becomes short hand for an amazing6 coincidence that is of benefit to a person or persons7. It would then seem that our definition of miracle actually stems from our own inability to sufficiently appreciate how probability acts in our lives. How many of us are in a position to calculate how probable any particular event is? Our normal day-to-day experience is a poor guide regarding this but if we cannot perform the calculation then by what basis do we conclude that an event is likely or unlikely?

I will readily admit that musings like this are have little practical significance but I think are still worth considering in order to develop for ourselves a more consistent and precise outlook. I hope that there are others beside myself that also see value in this.

footnotes

1. In general not this particular entry.

2. Who am I kidding? I don’t go to parties.

3. The definitions were broken down into 4: a) Violation miracles where the laws of nature are violated; b) Willed miracles where miracles occur via an act of a supreme being’s will; c) Inexplicable miracles where the event is unexplainable via the laws of nature though does not necessarily violate them; and finally d) Coincidence miracles, as discussed in this article.
See Nicholas Everitt’s “The Non-Existence of God” p112-ish.

4. Okay, that’s an exaggeration, but certainly more often than my experience tells me it should be used.

5. Try putting the word “miracle” into google news and see how many look explicitly religious.

6. Or not so amazing, depending on your point of view.

7. Miracle is definitely easier to say, though it does leave us open to misinterpretation by those who apply a more strict definition of the word than we do.

Enhanced by Zemanta

Filed under: Psychological, Religion, Sciblogs, Science, skepticism Tagged: Christianity, Existence of God, God, Miracle, Opposing Views, Philosophy, Physical law, Religion and Spirituality, Wikipedia

Print This Post Print This Post

Is there Something Fishy about Psychosis? Darcy Cowan Jul 02

No Comments

ResearchBlogging.org

Psychosis is a scary word, conjuring images of people who have so lost touch with reality that they are unable to integrate with society. As with most everything else this condition exists on a continuum, mild symptoms may pose no problem for the sufferer1 nor be outwardly visible. Previous studies have seen correlations between the intake of polyunsaturated fatty acids (with the cute acronym PUFA2) and increased severity of psychotic symptoms, with this in mind a study was performed in Sweden looking at the dietary intake of fish and the incidence of psychosis symptoms in the general population.

In total 33,623 women completed the study which covered the period between 1991/92 to 2002/03 (with questionnaires at the beginning and end of this period). This group was then classified based on their answers to the questionnaires into 3 groups: Low, middle and high frequency of symptoms, where the low group included women with no symptoms. This gave a split of 18,411, 14,395 and 817 women in the groups respectively. The first question I had reading this study is how do you classify someone with psychotic symptoms? The women in the study completed two questionnaires to provide the information for this part.

The first was the Community Assessment of Psychic Experiences (CAPE, another cool acronym), this contained questions ranging from those looking at emotional states such as “Do you ever feel sad?”, to those that address personal perception like “Do you ever feel pessimistic about everything?”. Also included are the questions that we would more easily recognise as relating to psychosis such as “Do you ever feel as if a double has taken the place of a family member, friend or acquaintance?” or “Do you ever see objects, people or animals that other people cannot see?”.

There are also questions that might seem to generate positive answers from a wide range of the population that we would not consider psychotic such as “Do you ever think that people can communicate telepathically?”, a belief that if I can take what I see in the media seriously is becoming more widespread. And “Do you believe in the power of witchcraft, voodoo or the occult?” which thinking back to the furore that arose around the Harry Potter books is a view that is held by a disturbing number of people3.

Quite obviously simply answering affirmatively to these questions does not place you in the psychotic camp, it is the aggregate of these answers that matter as well as further variables that relate to these answers such as how these thoughts and experiences make you feel. The experience of seeing or hearing a loved one that has died is quite widespread but I don’t think general conclusions about the sanity of the general population can be reached using this information.

The second questionnaire was a variation on the Peters et al. Delusions Inventory (PDI, and the good acronyms come to an end). There is significant overlap between the questions asked in the PDI and the CAPE questionnaires, the main difference seems to be how each question is followed up. The CAPE approach simply asks how distressed the respondent feels if they answered affirmatively to a question (with a 4 point scale, Not distressed to Very distressed) while the PDI covers this aspect as well as asking how much the respondent thinks about it and how much they believe it is true.

Now how do the categories that I mentioned above (low, middle and high) relate to the results of the questionnaires? Rather than attempt to paraphrase the study I’ll just quote that bit:

“The “low level symptoms group” included women with no or few experiences of psychotic-like symptoms (≤3 “sometimes” and no “almost always” and “often” answers to any of the questions). The “high level symptoms group” included women with frequent experiences of psychotic-like symptoms (≥3 “almost always” or “often” answers). The “middle level symptoms group” was defined as participants not included in the low level or high level groups.”

Fairly simple, not as nuanced as I expect an in-depth psychological evaluation might be but that’s the limitation of performing a large scale study.

Finally, what were the results of the study regarding fish consumption and symptoms of psychosis? Interestingly the authors did not see a simple relationship between the two variables, there was no clear protective effect with increasing intake of fatty fish (those with high levels of PUFAs). Instead there was an optimal intake that was correlated with low (or no) symptoms, higher intake actually correlated with increased symptoms. The authors are unsure what could account for this effect stating:

“This puzzling finding may be due to unknown or known unhealthy constituents of fatty fish. For instance, environmental pollutants such as polychlorinated biphenyls (PCB) and dioxins are known to accumulate in fatty fish. Another possible explanation may be that the frequent intake of fish and PUFA may be advantageous in lower doses but disadvantageous in higher doses.”

The authors also caution that the study was not geared to determine a causal relationship between the variables merely how these were correlated4. Another interesting finding was that high levels of psychotic symptoms are also correlated with women who are both overweight and are smokers (and also for some reason migration to Sweden5).

Bottom line? Hard to say really, the results of this study are indicative but not definitive. The take home message in my book looks to be that it is a balanced diet which is most beneficial, including fish in your meals between 1 and 3 times a week or so. For those of us who aren’t keen on fish, supplements might be the answer but that’s really another question.

OpenLab2010 Submit To Open Laboratory 2010(What’s This?)

1. Indeed they may not even consider themselves to be suffering from anything untoward.

2. You might recognize Omega-3 as representative of this group.

3. For me that number is 5.

4. Remembering the adage: Correlation does not equal Causation.

5. So should the tourism board adopt the slogan “Sweden: You don’t have to be crazy to move here, but it helps”? Too insensitive?

–
Hedelin M, Lof M, Olsson M, Lewander T, Nilsson B, Hultman CM, & Weiderpass E (2010). Dietary intake of fish, omega-3, omega-6 polyunsaturated fatty acids and vitamin D and the prevalence of psychotic-like symptoms in a cohort of 33 000 women from the general population. BMC psychiatry, 10 (1) PMID: 20504323

Related articles by Zemanta
Enhanced by Zemanta

Filed under: Psychological, Sciblogs, Science, skepticism Tagged: Causality, Conditions and Diseases, Harry Potter, health, Health and Medicine, Mental health, Nutrition and Metabolism Disorders, Pollution, Psychosis, Religion and Spirituality, Schizophrenia, Science, Science and Society, Women’s Health

Print This Post Print This Post

Can the Order You View Things Affect Your Opinion of Them? Or, To Make a Good Impression Ensure You’re Introduced First Darcy Cowan Jun 28

1 Comment

“First the worst, Second the best, Third the golden eagle.”

The above is a rhyme from my youth1, the implication being that you really don’t want to be first in anything. First is the worst after all. Obviously this is not true in the world beyond the playground, firsts in every field are celebrated, sometimes in great disproportion to their inherent worth2. How then is the position of first regarded by the human psyche? Do we give it more weight in other areas of our life? Can the order that we see things influence how we think about them, can we be manipulated into seeing things a certain way just by controlling what we see first?

Perhaps unsurprisingly the answer is yes. I should qualify that, it should be surprising that the order in which we observe something affects our decisions about it. We are after all rational beings aren’t we? We take in information, process it and come to conclusions based on the merits of what we have considered. Well, sort of. We are in actuality a mess of conflicting thoughts and desires, we all come with our own preconceptions and biases that can distort how we view the world without our really being aware of them. Is it really so surprising that we’ve found another one? Not to me, though this one is weird.

So what am I talking about really?3 Work performed by Dana Carney4 and Mahzarin Banaji looked at how the order we are exposed to things can affect the way we think about them and lead us to conclusions that otherwise we might not be justified in making. In a series of six experiments the question of how much influence the order we are exposed to stimuli affects our actions is asked. The experiments progressed from relatively cautious beginnings showing an implicit bias (using the Implicit Association Test – IAT as discussed in my previous post here) without explicit bias (self reporting) or real world consequences to actual choice biases in the real world.

In the first two experiments pairs of images (horses or people) were presented and then were rated for preference by the participants using either the IAT or an explicit seven point scale (eg “I strongly prefer x to y”). The implicit test showed a bias towards the first picture seen while the explicit measure did not.

Progressing from this the second two experiments attempted to determine if this implicit bias could be revealed in actions in the real world. Both used a pair of small consumables, either chewing gum or a lollypop, that would be placed on a table sequentially. The participant would then choose which item they preferred and would get to keep the item. In the first experiment subjects had to choose as quickly as they could (“within one second or so.”), this mimicked the IAT. In this condition 75% of participants chose the item placed on the table first.

The second experiment in this pair took place using commuters in a train station. Once again subjects were asked to choose one of two items which they were shown sequentially, this time however they were asked to either choose quickly or to take their time (mimicking the explicit test). In this set up 62% of the subject chose the first item in the time-pressured condition while no preference was seen if they could take their time.

Finally the study authors decided to test whether the preference for items seen first was due to an impulse to regard these items more positively than later seen items or if it was because the condition enhanced previously held beliefs about the object. In other words perhaps the first gum you see isn’t taken because your are made to think it’s better than the second gum but because you already have a positive view of gum and have this positive view reinforced by seeing one type first and so chose it for that reason.

To try and tease out these factors the authors used pictures of convicts in the final two experiments in order to use a stimulus that would naturally be seen negatively. In this set up participants were asked to indicate which criminal was a better candidate for parole. If first seem items have a more positive aspect imparted to them by virtue of being first then the first convict would be chosen. If on the other hand a baseline feeling about objects is enhanced then the second convict would be chosen. Once again however the IAT showed a preference for the first convict seen, labelling them better suited for parole. Also again, no preference was seen in the explicit measures.

What does this tell us about the general human capacity for decision making. Well superficially it’s good news. Given the time we will deliberate and make decisions based on the evidence available. If however we are working under time pressures then our implicit biases may come to the fore. There are however certain decisions that the authors of this study point out are known to be subject to implicit bias, such as consumer brand preference or even treatment preferences of doctors for specific patients.

We should be wary then of this new bias that has been thrown into the mix. Our heads are already full of biases that we may or may not be aware of, only by attempting to identify them do we stand much hope in correcting or tempering their influence on us.

So next time you need to make a snap decision, try to slow down and think it through. You may make a better choice5.

1. There seem to be versions of this around the world but the one above is most common in New Zealand as evidenced by this report.

2. Looking at you gold medal in Olympic BMX.

3. And how many rhetorical questions can I fit into one article? (does this one count? [or that one? {ok I'll stop now}])

4. Of the “Is Your Boss A Better Liar Than You? Probably, Yes” post.

5. On the other hand you may not want to think complex decisions through too much.

Related articles by Zemanta
Enhanced by Zemanta

Filed under: Psychological, Sciblogs, Science Tagged: Dana Carney, Decision making, Experiment, Implicit Association Test, Mahzarin Banaji, psychology, Science, Science and Society, Social Sciences, Tests and Testing

Print This Post Print This Post

« Older Entries