Extinction Vortex of DOOM

How is it that I’ve never heard this cool phrase before? Well not so cool for the species it applies to but still, someone was having a good brain day when that one was coined. The idea of an extinction vortex has been around for almost 25 years but I’m only just hearing about it now (maybe I was asleep, I mean uh sick, that day in biology class). As the name hints an extinction vortex describes factors affecting declining species that make extinction for that species almost inevitable.

Image via Wikipedia

The paper that brought this phenomenon to my attention is eye-catching named “Trapped in the extinction vortex? Strong genetic effects in a declining vertebrate population“, published by researchers at the University of Gothenburg, Sweden. The paper looks at the genetic factors influencing the decline of an endangered shorebird the southern dunlin, specifically the effect of reduction of variation in the species due to inbreeding.

The most significant thing about this paper for lay readers is that the primary contributing factors pushing endangered species toward extinction need to be understood in order to put appropriate counter strategies into place. In this case the effects of inbreeding, likely due to reduced population size, have weakened the species and made it more difficult to produce healthy offspring. Protection of the nests and increasing the available habitat for the species did not significantly  impact the species’ steady decline. This implies that conservation minded programs should be aware that once a species is in decline multiple strategies, including reproductive approaches, may be required to halt the decline and bring the species back to a stable population.

With currently over six thousand threatened species recognised this would seem to be an important lesson to learn. If conservation efforts are to succeed then at risk populations must be fully evaluated to determine the approach that has the best chance. As noted by the study authors, genetic damage may be hardest to see (via casual observation) when the effects are most severe: when the damage is such that embryos perish before viable individuals can be born.

I can’t sum up better than the study authors themselves so I’ll let their own words wrap things up:

“We have shown that a declining population of a long-lived, endangered vertebrate suffers from substantial negative genetic effects. Our results highlight that ignoring genetics may underestimate the extinction risk of natural populations and thus lead to inappropriate conservation measures”

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• Backing Up Evolution (scepticon.wordpress.com)
• Rare bird that was feared extinct rediscovered in Afghanistan (telegraph.co.uk)
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What is the Harm of Alternative Medicine?

Yesterday fellow Sciblogger Grant posted about homeopathic medications in pharmacies and questioned the legitimacy of reputable organisations selling such patent snake oil. The comments to this entry reveal one of the most frustrating aspects of speaking out against unscientific medicine and can be summarised thusly: “I’m far too sophisticated to be taken in by this stuff myself but other people seem to like it and if it doesn’t work then what’s the harm?”.

This attitude is ever present and comes from a reasonable starting point i.e. everyone is entitled to their own opinion and it’s not my job to save them from themselves. I can totally get behind that, usually. When it comes to ineffective medications of the alternative variety however this impulse though understandable is misguided and I’d like to put down a few reasons why I think so, some are speculative but I think the possibility of harm is great enough that they deserve to be considered.

For a start there may well be direct harm caused by using alternative remedies. As there is little to no regulation of these medications then no proof of safety or efficacy is required for sale. Witness the Zicam debacle last year regarding a “homeopathic” cold medication.

Further more the possibility for indirect harm (as multiply alluded to by Grant) may be significant. In case your imagination is not up to the task I will outline a few ways this may be the case. For instance the underlying principles of something like homeopathy are no only unscientific they are in direct contradiction of the last 200 years of scientific understanding. If they are used as the basis of reasoning about health then the results can be more dire than someone getting a bad nights sleep (in the case of the homeopathic sleep aid Grant used as an example).

Use of these therapies for minor ailments by the “worried and wonky well” may increase the possibility they they will be used for more serious health issues where the results could be deadly.

Look no further than the position statement of the WHO regarding the use of homeopathy in the treatment of Malaria and AIDs (among other things). The consequences of such thinking could be incalculable in terms of human suffering and spread of disease. But what’s the harm, right?

Additionally it is one thing for adults to make an informed choice for themselves based on available evidence filter through their particular world view but what about when this choice id forced on their children? The recent case of parents being found guilty of manslaughter over giving homeopathic remedies to their sick daughter is a terrible reminder that sometimes it is innocent children that pay the price for people’s gullibility. But, you know, what’s the harm?

When ostensibly professional medical providers such as pharmacists sell demonstrably irrational treatments they lend credibility to them that the average person uses to base decisions on. I mean the wouldn’t sell it if it didn’t work, right?

So while I understand the commitment to individual autonomy and freedom of choice that leads to the “What’s the Harm?” question, I fail to see how this means that fraudulent therapies must be let off the hook simply because there is a demand for them.

This has been a more vitriolic post than I normally write but what’s the point of a blog if you can’t vent once in a while?

Smoking Bans and the Effect of Health Warnings

In the world today there is an increasing focus on the negative aspects of smoking and a concerted attempt to reduce the presence of smoking in society. Given the harmful effects of this addiction on not only the active smoker but those around them this seems like a prudent move. Two of the approaches with the goal of minimising public exposure to cigarette smoke are the banning of smoking in businesses and public places and the addition of more strenuous warning labels on the cigarettes themselves.

Both of these tactics have been used in New Zealand with varying levels of acceptance (and success). Smoking bans draw the criticism that individual freedoms are being curtailed. This may be a legitimate point but conceptually it is no different than government enforcement of wearing seatbelts while driving on public roads. The aim is to reduce the risk of harm to the public. The real question in each case is whether the intervention is effective in it’s goals.

Addressing this question two studies last year looked at each of these methods, the first I will look at is a meta-analysis (with the concomitant problems those have, that’s another story) of the effect of smoking bans on the hospital admissions of acute myocardial infarction (that’s a heart attack to you and me). The analysis found that smoking bans were associated with an average reduction of heart attacks by 17%.

For each year a ban was in place it was accompanied by a reduction of the incidence rate ratio (the number of new cases per unit of population eg 10 cases per 100,000 people) of 26%. This indicates that the longer a ban is in force the fewer people who will be affected by heart attacks. Looks like an effective strategy to me, 17% is nothing to be sneezed at when it is individual lives you are considering. Depending on individual risk factors the chance of death in the 30 days after a heart attack can be up to 16%.

An editorial discussing these findings in more depth (in the Journal of the American College of Cardiology, the journal this study was published in) can be found Here and is a good read.

The second study focused on the how well explicit (i.e. emphasising death) cigarette pack warnings encouraged smokers to quit. Specifically it looked at smokers for whom the act of smoking formed part of the basis for their self-esteem. Subjects undertook a questionnaire that evaluated whether smoking was tied to their self esteem using statements like ‘‘Smoking allows me to feel valued by others,” and ‘‘Smoking allows me to feel worthy.” (as well as negative versions). The subjects rated how much they agreed with the statements and this was used to determine the smoking-based self esteem for each subject.

Participants were then shown pictures of cigarette packs that either had mortality related warnings (e.g. ‘‘Smoking leads to deadly lung cancer.”) or more moral or self esteem related warnings (e.g. ‘‘Smoking brings you and the people around you severe damage” and ‘‘Smoking makes you unattractive”). After a delay to allow the warnings to be filtered out of conscious awareness the subjects were asked a further series of questions to assess the effect of the warnings (e.g. ‘‘Do you intend to smoke more or less in the future?” ‘‘Do you intend to quit smoking in the future?”).

Subjects for whom smoking formed part of the basis for their self esteem actually increased their likelihood of smoking in response to warnings emphasising mortality. For these people it was the self image warnings that were most effective. Unfortunately is seems that the opposite is true for individuals that do not consider smoking to be an important factor of their self esteem so a one size fits all approach would probably not be effective. The study authors suggest that specific populations could have warnings tailored to be most effective depending on the relevance smoking has to the group identity (e.g. “young smokers who want to impress their peers.”).

This result may be applicable to other areas where minimising harm is the goal, such as drink driving campaigns.

In summary, despite any reservations regarding the form that inducements to stop smoking take it seems that the benefits are indeed worth the attempt. Also, as I often point out, the real world is more nuanced and complicated than we would generally like it to be, more effort may be required to identify sub-groups that respond most to different strategies but this also looks to be worth trying.

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I Trust You More if I Think You Think I’m Attractive.

As always things aren’t as simple as headlines suggest and the headlines of science based blogs are no exception. Of course people don’t actually go around assessing how attractive other people think they are and modifying their behaviour accordingly. These psychological biases and effects go on below conscious awareness but the point is that they do happen. Previous studies have shown that humans will tend to treat attractive people better and trust them more than unattractive people. Recent research has looked at whether this increase in trust can work both ways, that people will be behave more trustingly the more attractive they are.

While not immediately obvious it would make sense for this to be the case, consider that trust is a sort of social contract and we have an implicit understanding of the levels of trust individuals in our lives deserve. If greater trust is afforded to one segment of the population based on a scalable factor such as attractiveness then a reciprocal increase in trust based on this would tend to develop in order for this social contract not to break down. In addition to attractiveness people have also shown to act more altruistically and trustingly towards others when they know they are being observed. This also makes sense, we seem to have a high sensitivity to how we are perceived by others and for good reason, how we are perceived affects how we are treated.

In this study subjects participated in an economic trust game, in this game the first player is given an amount of money, this player can then choose to give a second player a proportion of this money (an act of trust), the second player then has the amount he or she received multiplied by a factor (say three) and can then choose how much money to give back to the first player. Each player then keeps the money they have left in their pool at the end. In this way the amount of trust shown by the first player can influence the amount of money they receive back, a highly trusting person may give a large proportion of their money with the expectation of receiving an even larger amount back.

Participants in this game tend to give more money if they know they are being watched, or even if there are simply pictures of eyes visible to them (tapping into the social aspect of our behaviour). In this variation the participants were told that they were visible to the other player and their behaviour was then matched with how attractive they were, as determined by a panel of raters looking at photographs of the participants. The subjects’ estimation of their own attractiveness was also gathered and showed a positive correlation with the external rating (ie if a participant considered themselves attractive then other people were likely to as well).

The findings showed that in general the more attractive the participant was the more trusting their behaviour, if they thought the other player could see them. How the results were correlated also supports the contention at the start of this post, that this is not a conscious process. The researchers found that if they controlled for the external evaluation of attractiveness then the estimation of self attractiveness did not seem to correlate well with increased trust. The implication here is that this is a learned behaviour based on how they were treated by others in the past.

This is not to say that good looking people are always deserving of trust but it’s nice to know that, at least in this one instance, trusting behaviour can beget more trusting behaviour down the line. I find that a very optimistic result.

Hands, Eyes and Uses for Bricks

Are you Right, Left or mix-handed? Haven’t heard of mix-handedness? Current thinking in neurology and psychology seems to be leaning towards describing handedness as a function of the degree of preference for one hand or the other. For some tasks you may use your right hand, others your left, it is the amount or preference you show that will determine what handedness you are. Not sure now? This page has a simple test that aims to determine hand preference by asking about simple tasks and which hand you prefer to use.

The test involves thinking about tasks (such as writing and drawing) and deciding which hand you prefer to use.Each answer is given a score for each hand your handedness is then given a score using the formula: (Right – Left) / (Right + Left). A pure Left hander will score -1.0, conversely +1.0 indicates pure right handedness, intermediate scores show mix handedness with a preference one way or the other. One thing to note here though, a score of 0 does not necessarily indicate ambidexterity.

This approach may indicate how well the two hemispheres of your brain communicate with strong handedness correlating with less communication and mix handedness with more. So how well are your hemispheres getting along?

This concept of communication between hemispheres is also being implicated in more abstract capabilities such as creativity. A recent study (very well summarised Here and Scientific American’s 60 Second Science podcast) looked at whether creativity can be increased in individuals who performed an exercise designed to increase cross-hemisphere communication. The exercise involved having the study participants move their eyes back and forth horizontally for 30 seconds. This activity likely increases the amount of hemisphere cross talk due to the fact that for each eye the right side of the visual field is processed on the right side of the brain and the left field on the left, this is represented diagrammatically Here (this can lead to a fascinating pathology called Hemispatial Neglect where a patient acts as if the left side of the world simply does not exist, not relevant here but too interesting not to include).

So moving your eyes back and forth means that each side must communicate a little more while forming a coherent whole for the visual field. This extra communication may then carry over to other tasks, that was the hypothesis. The measuring of creativity would seem to be a tough call, in this case participants were asked to come up with as many different uses for mundane objects (like bricks) as they could, participants were regarded as more creative when they came up with more categories of use and uses not thought of by other participants (originality).

The study found that the exercise did have an effect but that the strength of the effect was determined by strong handed or mix handedness. Strong handers had a creativity boost for 6-9 minutes (depending on the type of creativity, originality or more categories of use). If you are a mix hander then there is no benefit from the exercise, but don’t be worried, you are more creative than the strong handers in the first place. The increase of the strong handers performance really only seems to bring them up to the mix handers level.

Perhaps then, if you favour one hand much more than the other and you need a quick increase in creativity, you could do worse than this simple eye exercise. For once science has come up with an easy answer.

Persistent Vegetative States and the Problem with Facilitated Communication

If you read the print version of the NZ Herald today you would have seen featured on the front page a miraculous case of a man [Rom Houben] recovering from a persistent vegetative state and communicating with the world through a touch screen with the help of a carer. The topic of persistent vegetative state (PVS) is an interesting one and has received increasing attention in recent years. It would seem that this man was incorrectly diagnosed after an accident as being in a PVS while at the time of the accident it is more likely that he was in a minimally conscious state (MCS). A fine distinction sometimes and an excellent summary of the differences between the two diagnoses and the difficultly of accurately deciding between them can be found at the Science Based Medicine site.

Essentially a PVS is defined as the patient exhibiting no signs of consciousness, as with everything, whether you find something is dependent on how hard you look, simply opening a couple of drawers and glancing in the cupboard may not turn it up. In determining a case of PVS a more thorough search will reveal fewer legitimate cases as you may find extremely subtle signs of intermittent consciousness that will then flip the designation to a MCS. This process is also dependent on the sensitivity of the equipment used to perform the examination, the sophisticated scanning technology we have today simply did not exist 20 years ago. This equipment is the equivalent of rummaging around in the back of the couch and looking behind the fridge.

That this man was unfortunately diagnosed incorrectly is not in dispute, we have made significant advances in brain imaging technology that allows us to determine activity quite well. The issue here is the man’s ability to communicate so coherently and poetically. After so long without mental stimulation it seems bordering on the fantastic that this could be the case. When watching the video of the touch screen being used to bring this man’s thoughts to the world it seems very close to a practice known as Facilitated Communication, (this is actually confirmed in the TimesOnline article) this consists of a facilitator supporting the arm or hand of a subject ostensibly to allow them to then choose letters and words themselves which otherwise they would not have the strength or the focus to do.

The difficulty here is that this technique is very susceptible to the unconscious influence of the facilitator. In this way it can seem as though it is the patient communicating when in reality it is the thoughts of the facilitator that we are hearing. It is difficult to say for sure in this case, the video is ambiguous as to how much control the patient has over his movements so it is possible that we are indeed being exposed the inner world of a man with a very unique perspective but from the evidence shown it is equally plausible that the facilitator is the true originator of these words.

I would be interested in if any simple tests to determine the true origin of this material have been carried out, some of the suggestions I have seen elsewhere include swapping the facilitator for someone who does not speak the patient’s language, asking the patient questions that presumably only he would know, or asking the facilitator to leave the room while the patient is shown an object or told specific information and then seeing if this can be reliably produced after the facilitator returns. Any of these would help determine whether this man is truely communicating.

The print version of the Herald is mostly credulous in it’s coverage of this story but it appears that enough scepticism has filtered through the journalistic world that the online version has incorporated some of it. Better late than never.

[EDIT: The incomparable Dr Novella of the SGU and SBM has posted his take on this news item, as I hoped he would. Get the thoughts of a neurologist. Also had to add a link to this video from Dr.N's site that shows the patient typing with his eyes closed, simply not possible. Added Patient's name]

Rats, Bad Decisions and Jelloshots

It is an accepted fact of life that alcohol and good decision making have only loose a acquaintance  with one another. Like ships passing in the night, they may meet or they may not. This is true for the momentarily intoxicated but does that propensity for poor choices follow us even after the libations cease? Adolescents who drink alcohol from an early age appear to suffer from impaired decision making skills later in life but the connection is not clear cut as to whether the alcohol lead to that ill advised life choice or if the bad decisions lead to the alcohol.

In an effort to tease out those threads researchers used rats to model behaviour. In this case to entice the rats to consume the alcohol they provided it as part of a “palatable gel matrix” or in common parlance, jelloshots. This allowed the researchers to promote high levels of voluntary alcohol consumption among the adolescent rats. Now to measure the effect of this alcohol on the rats decision making abilities they weren’t able to offer the rats stock market options or the choice of marrying Tony Veitch. To substitute for these sorts of things the rats were give a choice between low risk certain rewards and large but uncertain risky rewards.

Rats that had consumed large amounts of alcohol were biased towards the high risk behaviour even after 3 months without alcohol, or well into maturity. Whereas the control rats displayed behaviour that assessed the risk against the pay-off and went for the more certain rewards. Unfortunately the full study is locked behind a pay wall* so I can’t determine how the study was controlled, how reliable these results are and what they actually tell us about the link between early alcohol abuse and risk taking behaviour later in  life. If anyone has access to this info I’d appreciate it. In the absence of this information it seems as if the alcohol is a significant predictor of risk seeking behaviour independent of the innate predilections of the individual. Or to put it another way:

*Why is the best stuff hidden away? Universal Open Access, your day will come!

TXT Language Redeemed

Working in a laboratory, as I do, abbreviations and acronyms are a way of life. Seriously, if we had to enunciate all of those chemical names, procedures and tests work would grind to a halt. Even so I find myself despising TXT speak, reducing otherwise comprehensible words to single letters, whole sentences becoming a jumble of alphanumeric sequences drives me crazy. And what’s up with “BayB” it’s the same letters in a different order, what do you gain by that?! (Deep Breath)

Even so, perhaps I’m overly harsh on users of this emerging dialect, perhaps we should consider it properly as a new language and users as early adopters deserving of respect for the mental agility it requires. Or at least we shouldn’t stereotype those fluent in  TXT speak as illiterate miscreants with no respect for the English language. A study submitted to the journal Reading and Writing looked 40 subjects in the 12 – 17 age bracket to see if there was a correlation between use of TXTese and poor spelling ability in regular English.

Turns out, there isn’t. In fact those that used more abbreviations tended to be better spellers over all. In direct contradiction of the critics (including me) poor spellers of English also tended to make more mistakes in TXTese (though how this was determined I don’t know).

What does this mean for the future? Will we all descend into a perverted shorthand of truncated words? I doubt it. This new version of English may or may not flourish as time goes on but being a product of necessity due to character limits for SMS I suspect it may very well decline in use again once technology catches up to the ease of other communication methods. Perhaps future linguists will devote treatises to the rise and unfortunate fall of a promising new language. Perhaps not.

Twitter, The End Of The World as I Know It

Alright, up until this point I have viewed the phenomenon known as Twitter to be the vacuous outgrowth of a shallow internet culture and considered it beneath contempt accordingly. That said we should always allow ourselves the opportunity to change our minds with evidence, with this in mind I have been persuaded to give Twitter a try. After only a few hours and having made only a single twat* I still like it better than Facebook.

Hopefully this new tool will help me bring to you, my reader, interesting info in a timely manner. Currently the average time between something coming up on my radar and actually writing about it is approximately 4 weeks. So sign up to follow me and we’ll see where this little experiment takes us, either I will use it constantly giving you a deeper glimpse into my interests and widening yours or it will die the ignominious death of complete abandonment and apathy.

* Someone with an ego the size of mine will never “Tweet”

Backing Up Evolution

I’ve said it before and no doubt I’ll say it again but we know science works because it makes predictions that we can then measure against the universe and determine if the models we have created to describe it are accurate or not. One of the more successful models is the theory of evolution by natural selection. A criticism levelled against the theory of evolution by detractors is the claim that new information can not be introduced into the system, only taken away. This is actually false but lets consider how we might tackle this question scientifically

First, the underlying assumption here isn’t unreasonable, let’s explore it. The accepted mechanism of introducing change in an organism, change that natural selection can then act upon, is mutation. Mutations involve a mistake in the copying of an organism’s DNA, this might consist of a change in a single base of a gene (an insertion of an extra base, deletion of an existing base or swapping one base for another) or it might involve large stretches of DNA. The basic principle that is relevant here is the same, a change is made to the blueprints of life in our cells.

As you might expect there are many more ways of being wrong than there are of being right, any random change is more likely to introduce a defect in the complicated machinery of life than it is to create an improvement (bearing in mind that “improvement” is a value judgement that really cannot be applied here but don’t focus on the wrong part of the story). So on the surface it would seem that random change is very definitely a bad thing, mutations would likely lead to loss of gene function, and by extension, loss of information and specifically death of the individual.

How might evolution get around such a problem? One solution would be to make copies of critical genes, this way is one copy is damaged through mutation the other can still function and produce a viable organism. The “spare” gene would then be free to mutate and the resulting gene may be selected for or against by natural selection (or human breeders).

If you have been reading closely you will have picked up on our prediction, the genomes of organisms should contain copies of various genes that allow mutations to occur without harming the individual that accumulates them. It turns out this is exactly what we find.  A recent study found a significant amount of redundancy in the genome of Zebrafish which allows mutations to occur in genes critical to development without lethal consequences to the fish.

The researchers intentionally gave mutagens to populations of Zebrafish and looked for changes in fish morphology indicative of mutations. In particular they created a mutation that lead to the loss of most of the fish’s scales, similar to that of Mirror Carp. The mutation was traced to a gene critical to normal development, further investigation revealed that the gene existed as a redundant pair, only one of which being required for normal development.

It is tempting to talk about this phenomenon in terms of intention, the gene was duplicated so that it could mutate and provide raw material for evolution. This is a mistake however, evolution can not move towards any putative desired future state. the genes that are duplicated in this way will be random and the mutations that affect the genes will be equally random, there are likely many genes in the Zebrafish that are not duplicated and would cause death to the individual if they were to change. This does not detract from the fact that a proposed mechanism for introducing new information into an organisms genome has proven correct.

Science is Awesome.

Beware the Demons!!!!!*

Catching up on blogs from over the weekend this one on the Center For Inquiry blog particularly stood out in the category of conspicuous displays of crazy. Beware of demons in your Halloween treats. I try not to do posts that are just “Look at this other Blog” but this one was too good.

*And all those exclamation marks, you notice? Five? A sure sign of someone who wears his underpants on his head.’ — Terry Pratchett,Maskerade

Can Torture Ever Be Justified?

I don’t think I would be going out on too much of a limb if I observed that most of us find the idea of torture to be repellent. As social creatures it is natural for us to shy away from inflicting harm on our fellows, empathy stays our hand when ruthlessness might otherwise help us achieve our personal goals. This holds true both in normal social interactions and in the extreme situations of conflict. It requires a significant expenditure of effort for us to overcome our inbuilt aversion to causing pain.

Even so torture can be rationalised as being for the “greater good” such as in the hypothetical situation which illustrates when torture might be a reasonable recourse known as the “ticking time bomb” scenario. In this case it is supposed that a terrorist has planted a bomb in a populated area, the terrorist is captured but the authorities have not been able to ascertain the location of the bomb which might go off at any time killing hundreds or possibly thousands of innocent people. If the terrorist refuses to co-operate, so the logic goes, it is then not only permissible to resort to torture to extract the information it might even be obligatory in order to prevent greater harm.

This situation however contains a hidden assumption that if untrue leaves the entire argument moot, namely, torture leads to accurate information. If this assumption is false then the justification falls apart. Last week in the journal Trends in Cognitive Sciences Shane O’Mara argued exactly this point. The main thrust of O’Mara’s argument asserts that prolonged stress causes changes in the brain that make it difficult for the subject to accurately recall memories and make the implantation of false memories and confabulation more likely.

False memories can be laid down when a subject incorporates what they are told into their own memory as if it actually happened when it did not. Simple repetition of information can induce false memories in normal subjects, assuming that it does not also happen in stressful situations is not  particularly reasonable.

Confabulation is the involuntary creation of false memories in response to questioning when the frontal lobe of the brain is impaired. The subject believes what they are saying and so is not lying but the information may not be accurate in any meaningful way. Events from the subject’s past and imagination can be jumbled together without the ability to tell the difference between them, when or if they happened. As prolonged stress can have negative effects on the frontal lobe confabulation could be a real danger in torture situations.

In addition the subject will also be conditioned that while they are talking the extreme interrogation techniques are stopped, thus talking represents safety. There is no extra inducement to truthful speech. In this situation there is no immediate method of ascertaining the truth of the subject’s words and so as long as the subject continues to talk further interrogation is not necessary.

Given these objections and certainly in the absence of reliable data to refute these points the justification for the use of torture simply dissipates. I for one find this information very reassuring.

Disgust or Anger?

The ability to recognise the emotional states of those around us is a very useful tool which allows us to act appropriately in social situations. If this ability is impaired then it could lead to inappropriate reactions when dealing with others, this in turn could land us in hot water. An impairment like this has been suggested to explain the behaviour of delinquents, though it is unlikely to be a sole cause of antisocial behaviour.

A study published recently lends support to this hypothesis, published last month in the journal of  Child and Adolescent Psychiatry and Mental Health (or CAPMH for short, catchy) the study looked at 24 Japanese young adults that were serving time in correction facilities (in Japan). Simply put the researchers compared these so-called delinquents with a control batch of young people (matched for age and gender), in the ability to correctly match an emotion to a facial expression. Six basic emotions were represented with 8 different pictures each, so participants had to match a total of 48 pictures.

The emotions covered were anger, disgust, fear, happiness, sadness, and surprise, the prediction was that the incarcerated subjects would have difficulty interpreting some facial expressions and that this difficulty would skew the subjects towards misidentifying expressions as anger. This in fact did happen, the delinquent subjects actually identified disgust as anger more than the control group.

This interesting result is lessened in it’s impact somewhat due to the fact that the control group also made this mistake a large percentage of the time. This predilection in the delinquents however is an insight into how certain personalities might perceive some social situations as being more hostile than they really are. These personalities are also marked by being quick to anger and experiencing more intense anger than others so recognising how this occurs can be useful information in diffusing these situations and possibly diagnosis of individuals who might otherwise be labelled as simply “difficult”.

Simon Singh Granted Permission to Appeal,

This just in (sort of), for those following the unfortunate case of the British Chiropractic Association suing columnist and author Simon Singh for libel, Singh has just been granted the right to appeal original ruling on the meaning of his article. For those not aware of all of this see here for a rough run down of the back story.

See Jack of Kent’s blog for the legalese, thanks to The Lay Scientist for the breaking news.

Natural Health Expo(sed)?

Driving around Hamilton the past few weeks I couldn’t help but notice the signs sprinkled around the city for the “Natural Health Expo” which is to take place here this week end. As I perused the website for this event yesterday I was disturbed by the large number of anti-scientific “treatments” that will be showcased. Like my co-blogger Grant who has already posted on this, I was troubled by the amount of misinformation that will be leveled directly at consumers.

As I was pondering how to answer the bewildering array of AltMed that will be promoted I checked my email and found a great little article just published in Chiropractic & Osteopathy (made available through the open access publisher BioMed Central).

The paper, “Why do ineffective treatments seem helpful? A brief review” written by Steve E Hartman, looks at how practitioners and patients can fool themselves into thinking that ineffective medical interventions actually work. An excellent example of Evidence Based Medicine 101, Steve covers the cognitive biases that hinder our ability to draw logical conclusions in the medical sphere such as the Post Hoc, Ergo Propter Hoc logical fallacy, confirmation bias and cognitive dissonance. Also covered are explanations of how it can seem that a treatment has been directly responsible for improvement in a patient’s condition when it may not  have been.

The paper touches on disease natural history, which simply refers to how a particular malady might be expected to progress without treatment. Self limiting diseases such as colds, headaches and fatigue can be expected to get better on their own . If a patient is taking a treatment at the time, the treatment (rather than their own immune system) might erroneously be given the credit.

This combined with the overlapping arenas of the placebo effect and regression to the mean can be a powerful confounding factor when treatments are not being considered in light of scientifically controlled settings. The placebo effect is referred to frequently in common culture but regression to the mean is a less well known entity for the layman. Steven does a good job of explaining the concept, essentially people experience a variety of different intensities in their symptoms. Also they will tend to seek medical help when the symptoms become severe, knowing that the severity of the symptoms will tend to cluster about a mean value it is likely that whether treatment is sought or not the patient’s condition will tend to get better.

Thus the patient will feel relief and attribute that relief to what ever modality they are using at the time. Practitioners are not immune to these effects either and will in their practice see time and again that patients are getting better after their pet therapy is applied. In which case they will feel justified in proclaiming it works in the absence of confirming studies (or even in the face of disconfirming evidence).

The one aspect that I felt was missing from the paper, although it may have been obliquely implied, is the role of prior plausibility in evaluating treatments. Many modalities that will be on offer at the Natural Health expo are not only unusual they fly in the face of currently understood science. Scientific plausibility is our compass, without it we can become lost in the wilderness of fanciful ideas without any method of discerning the way forward. This concept is what separates Science Based Medicine from simply Evidence Based Medicine. The former takes the plausibility of a treatment into account when deciding the threshold of evidence needed before it can be considered effective. The later only measures outcomes and so is less able to distinguish true effects from chance outcomes.

Consider the following scenario: I claim to be able to influence the outcomes of coin tosses by virtue of what I had for breakfast on a particular day. If I have eggs then tails with predominate, lettuce produces more heads. Now without considering the plausibility of the setup we could run a trial, perform statistical analysis and find that my predictions are correct. But given that there is no good reason to suspect that my diet can influence a coin toss the positive is more likely to be because of chance than because of a real effect. In this case then a higher standard of evidence would need to be achieved than if I had said I could alter the probabilities be sticking a piece of gum to one side.

All-in-all though this a very nice paper and my complaint is a small one, given the probable readership of the journal the inclusion of plausibility may even have alienated those that might otherwise have been receptive to the other points presented. I recommend reading it for yourself, it is a very easy and informative read.