Archive for July, 2012

Jul 06 2012

Robot Legs and Central Pattern Generators

The most common response of my patients when I test their deep tendon reflexes is to giggle. I bang gently on the infrapatellar tendon, their leg kicks out involuntarily, and they giggle. While I am acutely interested in the reflex response and what that says about my patient’s nervous function, the giggle is perhaps the more interesting response. Many patients also comment something to the effect of, “That is so weird.”

What is weird is the experience of movement outside of our conscious control. We exist in a neurologically induced illusion that we own and control our limbs.  There are, in fact, specific circuits in the brain that generate the experience of ownership and control. We know this partly because of patients in whom those circuits are disrupted and lose their sense of either ownership or control. I guess it is also not surprising that we are conscious of the conscious level of control of movement, but not of the subconscious elements of control. We are occasionally reminded of them when a reflex supersedes are conscious control, an experience we find weird and often giggle-inducing.

The reality is that there are different levels of hierarchical control in our nervous system. More basic circuits provide automatic function and are literally (phylogenetically) more primitive than higher levels of more sophisticated control, all the way up to voluntary control from the cortex. We are not consciously aware of most of the processing that is needed to produce smooth and coordinated movement. If we desire to walk across the room, for example, we guide our movements to accomplish that desire, but we are not aware (thankfully) of the many components that go into the astonishing balancing act of walking.

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Jul 05 2012

Feathers More Common Among Dinosaurs

Published by under Evolution

The story of feathered dinosaurs is one of the strongest success stories for evolutionary theory, and continues to be a thorn in the side of evolution deniers. They cannot help but expose their ignorance and deception when they clumsily try to deny the implications of feathered dinosaurs. So I tend to revel, just a bit, in each new significant discovery of a feathered dinosaur. The latest discover, recently published in PNAS, provides evidence that feathers were even more common among dinosaurs than previous evidence demonstrated. There is some debate among experts about how prevalent protofeathers and feathers were, and so a new piece of solid fossil evidence helps clarify the debate further.

After Darwin published his theory of evolution one of the early challenges to the idea of evolution, which includes the claim that all life on earth is related through common ancestors, was that there were significant gaps between major groups of living creatures. Birds, for example, seem to be their own group without a close connection to any other group. They are, of course, related to vertebrates. But if evolution were true then there must be fossil evidence connecting birds to another group, such as reptiles.

Right around that time the first specimens of Archaeopteryx were discovered (the London specimen in 1861 and the Berlin specimen in 1874). These are beautiful transitional fossils showing features of both theropod dinosaurs and birds Рexactly as Darwin predicted. For decades Archaeopteryx stood as the sole species bridging birds and dinosaurs, and creationists did everything they could to deny the implications of this fossil. They tried calling it a hoax, then just a regular dinosaur, then just a regular bird. They also argued that, whatever it is, there is no proof that it is actually transitional between dinosaurs and birds Рa non sequitur that betrays their lack of understanding of evidence in science.

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Jul 03 2012

GSK Pays $3 Billion Fine

The pharmaceutical giant, GlaxoSmithKline, has agreed to pay three billion dollars in fines to settle three charges of fraud brought by the FDA. This is the largest health fraud settlement in US history. What are the implications of this settlement for how the pharmaceutical industry is regulated in the US and for the role that “Big Pharma” allegedly plays in US health care?

The three fraud charges admitted to by GSK include promoting the off-label use of two anti-depressant drugs – Paxil and Wellbutrin. In the US drugs are approved for specific indications, and they can only be marketed for those indications. So-called off-label use of drugs, however, is very common. Off-label does not necessarily equate to bad medicine, or to lack of scientific evidence or rationale. Often there is solid basic science and clinical evidence to support a specific use of a drug that is not approved by the FDA. That simply means the manufacturer did not apply to the FDA for that indication, which could simply be because they did not feel they would recoup the millions of dollars they would need to spend to get approval for the additional indication. In other words, FDA approval for secondary indications is as much about marketing and finance as it is about the science.

Regardless of whether or not a specific use is evidence-based, however, the rules regulating pharmaceutical companies are very clear – they cannot market a drug for a non-approved use. Doing so breaks the law. GSK broke the law.

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Jul 02 2012

Genetic Misinformation

One of the themes of this blog is the misreporting of science information in the lay media, so I am always interested in a particularly bad piece of science reporting. Several readers pointed me toward this piece in The Telegraph about studying genetic ancestry. I know newspaper writers usually don’t write their own headlines, but in this case the headline is partly a quote from the article itself: “Scottish lecturer found to be ‘grandfather of everyone in Britain.'”

That is a misleading and useless characterization of the science story covered in the article. The phrase “grandfather of everyone in Britain” does appear as a quote from “scientists”, although no specific name is given. I know from personal experience and talking to other scientists who have been misquoted by the media that the presence of quotation marks does not mean that a real scientist actually uttered those words. It is possible that they did, however. Typically a reporter will interview an expert for thirty minutes or more about the topic of their report, and then use only small bits from the interview, or perhaps none at all. Good journalists will use the expert to help them understand the topic and shape the article they are writing. However, too often journalists (especially those who are not specifically trained as science journalists) will just fish for provocative quotes they can weave into the article they have already mostly written. Even worse, they may put quotes into the mouths of their experts. “Would you say that…”

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