Oct 20 2016

Chiropractic and Strokes

neck-adjustment-1In February Playboy model and instagram star Katie May died suddenly of a stroke at age 34. Recently TMZ obtained a copy of the coroner’s report from her autopsy which concludes that the stroke was due to a tear in one vertebral artery, which in turn was caused by neck manipulation by a chiropractor.

This is a good time to review the evidence surrounding the issue of chiropractic manipulation and strokes, which is a concern expressed by many experts but largely denied by the chiropractic profession.

Strokes in young people (<50) are extremely rare. A stroke is caused by blockage of an artery feeding the brain leading to lack of oxygen causing injury and even death to brain cells. Arteries can be blocked if a blood clot lodges in the artery (an embolus), or if a clot forms in the artery (a thrombus).

One major cause of young strokes is trauma to one of the four arteries that feed the brain: two carotid arteries in front and two vertebral arteries in back. The trauma can cause a tear in the inner lining of the artery, which is called a dissection. That tear causes turbulence in blood flow, which in turn can result in a blood clot (when blood isn’t flowing it tends to clot). That blood clot or thrombus can block the artery if it gets big enough, or a piece can break off and lodge down stream, either way causing a stroke.

Continue Reading »

Comments: 31

Oct 18 2016

The Hawthorne Effect Revisited

It’s always more complicated than you think. If there is one overall lesson I learned after 20 years as a science communicator, that is it. There is a general bias toward oversimplification, which to some extent is an adaptive behavior. The universe is massive and complicated, and it would be a fool’s errand to try to understand every aspect of it down to the tiniest level of detail. We tend to understand the world through distilled narratives, simple stories that approximate reality (whether we know it or not or whether we intend to or not).

Those distilled narratives can be very useful, as long as you understand they are simplified approximations and don’t confuse them with a full and complete description of reality. Different levels of expertise can partly be defined as the complexity of the models of reality that you use. It is also interesting to think about what is the optimal level of complexity for your own purposes. I try to take a deliberate practical approach – how much complexity do I need to know?

The Hawthorne Effect

The distilled narrative of what is the Hawthorne Effect is this – the act of observing people’s behavior changes that behavior. The name derives from experiments conducted between 1924 and 1933 in Western Electric’s factory at Hawthorne, a suburb of Chicago. The experimenters made various changes to the working environment, like changing light levels, and noticed that regardless of the change, performance increased. If they increased light levels, performance increased. If they decreased light levels, performance increased. They eventually concluded that observing the workers was leading to the performance increase, and the actual change in working conditions was irrelevant. This is now referred to as an observer effect, but also the term Hawthorn Effect was coined in 1953 by psychologist J.R.P. French.

Continue Reading »

Comments: 4

Oct 17 2016

Where Does the Power Come From?

perpetual-motion-1Yet another perpetual motion machine video is making the rounds. I do have a fascination with these devices, and this one is a great example of the genre.

This device was conceived and created by a Norwegian artist, Reidar Finsrud. He is clearly a talented, intelligent, and motivated artist. He reports that he became obsessed with the idea of his machine and spent many 18 hour days creating it. I do think it is a beautiful work of art and can be appreciated as such.

Finsrud, however, believes that the machine is an example of perpetual motion. At least that is the narrative of the documentary. Finsrud states that when he looks at his machine he feels like he is looking at fire, a the future, a future of free and egalitarian energy.

Perhaps that belief on the part of the artist is part of the art. It’s similar to the crop circle artists who won’t disclose (at least they didn’t for a while) that they were the artists, believing that the mystery about the origin of the crop circles is part of the art form.

At one point in the video Finsrud asks the question, “Where does the power come from?” He recounts how many scientists he has asked could not answer the question. That is another common theme in the genre of pseudoscientific devices or artifacts. The creator or promoter seems to always recount how they consulted experts who could not answer the mystery of the object. I think this is just a form of confirmation bias. When you dig deep you find that they were not consulting the right “experts,” or perhaps they were cherry picking the experts who gave them the answers they liked.

Continue Reading »

Comments: 33

Oct 14 2016

Science Is Not Colonialism

science-fallismThis Youtube video is making the rounds. Relax, tape a deep breath, and take a look at the video.

The core point that the primary speaker is making is this: Science is nothing but Western colonialism imposed upon the African people (and presumably others). The only solution is for science to “fall” – she would like to wipe away all of science and start with a blank slate, so that Africans can develop their own knowledge.

She gives as an example that Newton saw an apple fall, made up gravity, wrote down some equations, and now that is scientific truth imposed on the world forever (seriously, I am not exaggerating this one bit).

The other pillar of her position is that in Africa there are practitioners of black magic who can summon a lightening bolt at their enemy. This is not explainable by “Western” science, and yet this is African knowledge, and therefore is an example of Western colonialism suppressing indigenous wisdom.

After stating that practitioners can summon lightening, someone in the audience shouted “It’s not true.” While this might be considered rude, it is an understandable impulse. The response of the moderator was illuminating, in my opinion. She stood up, shamed the audience member, lectured him about the fact that he violated their safe space that is supposed to be free of antagonism, and then forced him to apologize.  Continue Reading »

Comments: 71

Oct 13 2016

GMOs and Horizontal Gene Transfer

horizontal-gene-transferPeople reject genetically modified organisms as food (GMOs) for a variety of reasons, but the single most cited reason is the false belief that they are unhealthy. That specific belief also represents the single greatest disconnect between the opinion of scientists and of the general public in a 2015 Pew poll, greater than evolution, climate change, or vaccine safety.

The reason for this disconnect is that the public is relying upon their intuition, rather than scientific knowledge, to arrive at their conclusion. Further, that intuition has been hijacked by a deliberate anti-GMO campaign orchestrated by misguided environmentalists and by the organic food lobby to help promote their brand.

As Stefaan Blancke and his coauthors argue in the above article:

This intuitive reasoning includes folk biology, teleological and intentional intuitions and disgust.

One of the primary “folk biology” talking points of the anti-GMO crowd is that it is “unnatural” to place genes from one species into a distant species. No further reasoning is offered to defend this position – just the invocation of what is “natural” seems to be enough. Those who defend the scientific position often point out that this irrelevant, just a manifestation of the appeal to nature fallacy. Whether or not something occurs in nature does not determine if it is good or bad for human health.

Continue Reading »

Comments: 14

Oct 11 2016

Is It Ethical to Study Homeopathy?

homeopathy-nosodesA Canadian academic, Dr. Mark Loeb, who is a respected infectious disease researcher who knows how to conduct high quality research, wants to study homeopathic nosodes. Nosodes are essentially homeopathic vaccines.

Tim Caulfield, a Canadian professor of health law and policy, thinks the study is misguided and unethical. The two are having a respectful public debate about the risks and merits of doing such a study.

David Gorski and I have actually published in the peer-reviewed literature on the broader question of studying alternative medicine: Clinical trials of integrative medicine: testing whether magic works? It is a bit of a dilemma, and we are seeing that exact dilemma play out on the question of this specific proposed study.

Homeopathy is Pseudoscience

For quick background, both sides in this debate agree that homeopathy is 100% pseudoscientific nonsense. Homeopathy was invented by one person, Samuel Hahnemann, about 200 years ago. It was not based on any scientific research or knowledge base, it did not develop out of emerging knowledge of biology or physiology. It was simply invented out of whole cloth based loosely on the superstitious belief in sympathetic magic – the notion that substances contain a mysterious “essence” that can be transferred to the body and stimulate the life force.

Continue Reading »

Comments: 13

Oct 10 2016

Modeling Misinformation

tweetdemicAs social media changes the nature of information and communication, it is interesting to think about how information and misinformation spread through these networks. A paper from 2015 seeks to model the spread of information through social networks to better understand the effect of specific variables.

The study: Fact-checking Effect on Viral Hoaxes: A Model of Misinformation Spread in Social Networks, is not a real-world examination but a mathematical model. As with all such models, it is overly simplistic in order to isolate a few key variables. For the purpose of this model they are treating misinformation as a virus. Someone exposed to the misinformation is potentially infected. At random, they will either be gullible, believe the misinformation and spread it on, or they will be skeptical, fact check the misinformation and then spread correcting information.

In the model they can vary the percentage of people who are believers vs fact checkers. They can also vary the time it takes on average for people to forget the information and therefore become susceptible to infection again. They used a stochastic model, which means the spread of the information and whether or not an individual is a believer or fact checker was random.

They found, not surprisingly, that the greater the percentage of fact checkers, the more likely it is that the hoax will essentially be wiped out. If the percentage of fact checkers is too low then belief in the hoax can become endemic – it can persist indefinitely in the population.

Interestingly, the rate at which the misinformation spread did not matter in this model.

Continue Reading »

Comments: 8

Oct 07 2016

CAM Harming Children with Autism

snake-oil1Children with autism are an especially vulnerable population. Just being a child makes you vulnerable, especially when you have any medical condition. You are in the hands of your parents, the health care system, and the state to best look after your needs.

Unfortunately, we frequently see stories in which all three have failed to look after the needs of children (sick or not).

Another such story has surfaced: the BBC reports about a four-year old boy, recently diagnosed with autism, whose parents sought help from a naturopath. This fake doctor prescribed a dozen supplements to the boy (because that’s what they do), apparently telling the parents this would help with their son’s autism. Instead, the boy became extremely ill and would likely have died without critical intervention.

Specifically, he was given a toxic dose of vitamin D (yes, there are toxic doses of vitamins), which caused him to have dangerously high calcium levels. He developed vomiting, extreme thirst, and lost 6.5 pounds in 3 weeks. Fortunately he was treated and has recovered.

Continue Reading »

Comments: 3

Oct 06 2016

The Longevity Debate

lifespan-tableA recent study that concludes human lifespan is approaching its maximum (around 115 years) has created some interesting debate. It’s the good kind of scientific debate that focuses on how to interpret data and infer the implications of limited data.

The authors, Dong, Milholland and Vijg, examined the mortality database, which includes death statistics from 38 countries. They looked at the age of the oldest person to die in each country by year. They also looked at the change in life-expectancy by age group.

To clarify one point of terminology that is often confused: life expectancy refers specifically to the number of years a person is statistically likely to live from their current age. Usually when you see life expectancy figures quoted, those are life expectancy from birth.

For example, a person born in 2012 in the US has a life expectancy of 78.8 years. If you were 65 in 2012 in the US your life expectancy was 84.5 (both are slightly higher for women and slightly lower for men).

Continue Reading »

Comments: 17

Oct 04 2016

Review – Brain Training Games Don’t Work

brain-gamesYesterday I wrote about the literature on so-called “power poses” – the notion that adopting certain poses make you feel more confident and powerful, and therefore change your behavior in certain ways that may be advantageous. Over the last decade psychologists have built up a literature which they claim supports the conclusion that power poses work.

However, a reanalysis of the data suggests that the evidence is flimsy, and in fact may be entirely an illusion created by p-hacking (essentially, loose research methodology).

The primary proponent of power poses, Amy Cuddy, has already built a career on the idea, topped off with a popular TED talk, and so far is sticking by her conclusion. Meanwhile, one of her coauthors, Dana Carney, has already jumped ship and stated publicly she does not think the power pose effect is real.

Brain Training

Today I am going to tell a very similar story, this time about brain training games. Over the last decade psychologists have built up a literature which they claim supports the conclusion that playing certain “brain games” will make you smarter in general, and may even stave off dementia.

Continue Reading »

Comments: 18

Next »