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Why Isn’t the Spinning Dancer Dizzy?

by Steven Novella, Sep 30 2013

This is not a reference to the spinning dancer optical illusion, but rather to real dancers. Why don’t ballet dancers get dizzy when they spin around? Partly this is due to technique – a technique called spotting, in which dancer keep their head in one position for as long as possible then rotate it around quickly back to their fixed position. You have likely noticed this while watching ballet dancers.

But spotting does not entirely explain the ability of experienced dancers to tolerate spinning without becoming vertiginous. A new study finds that brain plasticity is also playing a role – the brains of experienced dancers adapt by reducing the signals that would cause dizziness.

To clarify, the term “dizzy” is a bit non-specific. People use it to mean vertigo (the sense of spinning or movement), but also light-headedness (feeling as if you might pass out), just being off balance, or even for any vague sensation in the head. What is being addressed in this study is vertigo, the feeling you get if you spin around.

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Body Image and Giving the Finger

by Steven Novella, Sep 23 2013

The most astounding sensory illusions occur by exploiting brain processes you are not aware even exist, or need to exist. Definitely in the running for the best such illusion are body ownership experiments. Your brain uses sensory information to decide which parts of your body you own, control, and where they are in three-dimensional space. This process can be easily fooled into creating an alternate image – making you feel as if you own and control fake body parts, and even virtual avatars.

Various researchers have consistently shown this basic effect, while they explore the details and limits of this phenomenon. One such experiment, published today in the Journal of Physiology, adds a few new details to the picture.

Researchers had subjects hold an artificial finger in their left hand. They then had them flex their right index finger, while the artificial finger also flexed itself. They were blocked from seeing their hands, and the skin of their right hand was numbed with medication. Subjects then reported that they were holding their right index finger.

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Another Sighting

by Steven Novella, Sep 09 2013

You are driving down a dark road at 5:30 AM. Chances are, you’re a bit sleepy. Something suddenly runs across the road in front of your car. Your headlights catch it briefly as it dashes into the woods on the other side of the road. What was it?

That, apparently, was the question faced by a 15 year old Nebraska boy – why a 15 year old was driving was not addressed by the article. It seems his early morning brain processed the unexpected sensory input into – Bigfoot.

There is no credible evidence, after decades of search, that anything like Bigfoot exists anywhere, least of all Nebraska. The flat state does not contain the vast forests that would be necessary to conceal a breeding population of large primates. Despite that, there have been 14 reported sightings in Nebraska since 1957.

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Probiotics for Mental Health?

by Steven Novella, Aug 26 2013

I frequently criticize science journalism for falling into one or more common traps – false balance, hyperbole, misleading framing, failure to put one study into the proper context, inappropriate extrapolation, and others. Here is one article discussing the relationship between gut bacteria and mental health that can be used as a textbook example of how not to write a science news story.

The article begins, as is unfortunately often the case, with an emotional anecdote. Journalists are taught to find a human angle to draw the reader in, and I get this. But this style is better suited to fluff pieces than serious science journalism.

There are multiple problems with this style as applied to a science topic. The first is, of course, that the story is anecdotal. We cannot know what the implications of this story are. It is likely highly selected – chosen out of many possible examples to be the most dramatic and emotionally appealing example of whatever story the journalist wants to tell.

In this case we are told the story of Mary who has severe refractory obsessive compulsive disorder (OCD). All the emotional hooks are there – her parents are desperate, all previous treatments have failed, and the doctor they are seeing (the focus of the piece) is their last hope.

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Area 51 Revealed

by Steven Novella, Aug 19 2013

Area 51 is more than just a subject of UFO conspiracy mongering, it has graduated to a fixture in pop culture. Everyone knows what Area 51 is, or at least what it’s supposed to be. Mention crops up in movies, such as Independence Day.

According to the CIA this facility’s official name is the much less alluring, Nevada Test and Training Range at Groom Lake, a remote detachment of Edwards Air Force Base. It is part of a 23 x 25 mile area of restricted air space. For decades there have rumors that Area 51 is a secret base where the US government has recovered alien spacecraft and conducts research on those craft.

The government denies these claims, but has never said what Area 51 is really for. It has never been mentioned in any public document, and documents obtained through any freedom of information act (FOI) request have never mentioned Area 51 (any possible mention being redacted).

George Washington University’s National Security Archive senior fellow Jeffrey Richelson made a FOI request in 2005 for information on the U-2 spy plane program. He received a 400 page reports entitled, “”Central Intelligence Agency and Overhead Reconnaissance: The U-2 and Oxcart Programs, 1954-1974.” In this document the name Area 51 is no longer redacted – it is mentioned as the base at which the U2 was developed and tested.

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Changing Your Fate

by Steven Novella, Aug 05 2013

There is a cartoonish sight gag that I have seen multiple times – a patient lying ill in a hospital bed has some indicator of their health, on a chart or monitor. The doctor comes by an flips the downward trending chart into an upward trending one, or adjusts the monitor so the readings are more favorable, and the patient improves.

This is a joke that a child can understand, even if they don’t explicitly understand that the humor lies in the reversal of cause and effect. And yet more subtle or complex forms of this same flawed reasoning is quite common, especially in the world of pseudoscience.

Even in medicine we can fall for this fallacy. We often measure many biological parameters to inform us about the health of our patients. When the numbers are out of the normal range it is tempting to take direct action to correct those numbers, rather than address the underlying process for which they are markers. Medical students have to learn early on to treat the patient, not the numbers.

Of course when the underlying belief is magical, rather than scientific, it is hard to argue against just changing the signs so that the reading is more favorable. Since the cause and effect is pure magic to begin with, does reversing it make it any worse?

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Legal Courts And Science

by Steven Novella, Jul 29 2013

Facebook is like a graveyard in a zombie movie, where old news items rise from the dead to have a second life. I am often asked about news items that are burning up Facebook, only to find that they are years old, but never-the-less they have to be addressed all over again. ]

One such item (actually a few items) is a 2012 news report about the Italian courts awarding money to the Bocca family a large reward because it concluded their 9-year-old son acquired autism from the MMR vaccine.

History here is a useful guide. The courts have historically often been out-of-step with the science, tending to err on the side of awarding compensation for possible harm. For example, until about the 1920s it was thought that physical trauma could cause cancer. Animal studies and epidemiological evidence, however, showed that there was no causal connection. Recall bias and increased surveillance were likely the cause of the apparent association.

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Forget Amnesia

by Steven Novella, Jul 22 2013

A recent article in The Guardian has the provocative title, “American man wakes up with amnesia speaking Swedish.” The article itself contains some significant misconceptions about amnesia, and so is a good opportunity to discuss this interesting topic.

In brief, amnesia is a pathological loss of memories (not just normal forgetting). The most common type of amnesia is traumatic – caused by trauma to the brain. Trauma can cause retrograde amnesia, which is loss of memories prior to the injury, and anterograde amnesia, which is loss of memories following the trauma. Contrary to the common movie cliche, these lost memories cannot be recovered by subsequent head trauma (or by any other means).

Another cause of amnesia, especially anterograde amnesia, is drugs. Alcohol and benzodiazepines in particular can prevent the formation of memories while intoxicated.

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Transcranial Magnetic Stimulation for Autism

by Steven Novella, Jul 01 2013

A clinic known as the Brain Treatment Center (BTC) is offering what they call Magnetic Resonance Therapy, or MRT™, as a treatment for autism and other disorders, including sleep disorders, schizophrenia, Alzheimer’s disease, emotional disorders, anxiety, addiction, and for athletic performance.

MRT (always be suspicious of a medical treatment that is trademarked) consists of transcranial magnetic stimulation along with other modalities:

…EEG, brain stimulation, Neurofeedback, EKG and other biometric techniques to provide a highly customized treatment personalized to how a patient’s brain takes in, processes, and communicates information.

I will discuss both the use of transcranial magnetic stimulation (TMS) for autism, and the specific claims made by BTC, starting with the latter.


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Who’s To Blame For Fraud?

by Steven Novella, Jun 24 2013

By now most readers have probably heard that Jim McCormick, the maker of the fake bomb detectors, was convicted on three counts of fraud and was sentenced to a maximum of 10 years in jail. My reaction to this, echoed by many other skeptics, was – only 10 years?

To recap – McCormick repurposed fake golf ball detectors, which were basically fancy dowsing rods, as bomb detectors. He sold the $20 novelty items for thousands of dollars. He then made his own version of the devices, still worthless dowsing rods, but made to look fancy. He sold them for tens of thousands of dollars each as bomb detectors. They were used at Iraq checkpoints, among others. At checkpoints where his fake devices were used, undetected bombs exploded, killing and injuring hundreds to thousands of people.

This has raised several questions. The first is the appropriateness of the sentence – just 10 years. Apparently that is all the law allowed for. The judge in his decision, in fact, felt the need to justify giving him the maximum sentence. He is quoted as saying:

Judge Richard Hone at the Old Bailey court said he was taking the rare step of passing the maximum possible sentence because of McCormick’s “cavalier disregard for the potentially fatal consequences of his fraudulent activity.”

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