Archive for April, 2008

Apr 15 2008

Decision Making in the Brain

Neuroscientists are wrangling with the question of decision-making and free will – by which I mean they are looking at what the brain is doing during the process of decision-making. The deeper questions of free will – what is it really and what are the implications of neuroscience for free will – are far more squirrelly. I am not convinced that free will questions are strictly scientific, at times they sound very philosophical, meaning that there are components of perspective and even meaning. But scientists and science reporters love to speculate about the deeper philosophical implications of fairly reductionist research.

The current issue of Nature Neuroscience contains a brief report about an fMRI study looking at brain function during a particular decision-making task. Subjects were asked to hit a button with either their right or left hand. The fMRI revealed that areas of their prefrontal and parietal cortex showed activity about 7 seconds before subjects hit the button. Prior research has shown that before we make a movement, about 300 miliseconds (3/10 of a second), the pre-motor cortex lights up. This makes sense, the premotor cortex is responsible for initiating movement. This new study shows that we plan our movement before we send a signal to the premotor cortex to initiate it – and then on to the motor cortex to actual perform the movement.

But here is where things get interesting. The subjects were not necessarily consciously aware of their decision until they were about to move, but the cortex showing they were planning to move became activated a full 7 seconds prior to the movement. This supports prior research that suggests there is an unconscious phase of decision-making. In fact many decisions may be made subconsciously and then presented to the conscious bits of our brains. To us it seems as if we made the decision, but the decision was really made for us subconsciously.

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Apr 14 2008

The Expelled Hitler Fallacy

Published by under Creationism/ID

The scientific community has been working overtime exposing the lies, errors, and fallacies in the Intelligent Design (ID) propaganda film, Expelled: No Intelligence Allowed, staring Ben Stein. It’s no wonder – it’s hard not to be offended by this film. It is a work of deception from beginning to end. As Eugenie Scott reveals on the March 26th episode of the Skeptics’ Guide podcast, the scientists in the film were deceived as to the nature, title, and production company of the film at the time of their interviews. Simply put – they were shamelessly sandbagged. The content of the film is crafted deception. And the rollout of the film has been tainted with blunders covered up by more lies.

But what raises the entire affair to the level of visceral disgust is the manner in which this film attempts to blame “Darwinism” (their favorite term for those who accept evolution as a well-established scientific theory) for Hitler’s holocaust. This bit of propagandistic nonsense (if an ideologue loses the scientific battle of logic and evidence they have no choice but to fight a propaganda war of lies and deception) has been thoroughly refuted by others, even before this film was made. But I want to focus on one logical contradiction that, to my knowledge, has been glossed over (my apologies to anyone who has pointed this out and escaped my notice). Evolution deniers refute evidence for evolution from breeding and cultivation because the human-imposed selection is not natural selection. At the same time they link evolution to Hitler’s program of genocide – even though the holocaust also did not involve natural selection, but rather imposed artificial selection through murder and sterilization.

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Apr 11 2008

Repairing Stroke with Stem Cells

Published by under Neuroscience

Repairing brain function following a stroke is likely to be one of the early applications of therapeutic stem cells. Stem cells are undifferentiated or “generic” cells that have the potential to turn into more specific cell types as needed. There are different degrees of pluripotency (the ability to differentiate into different cell types) depending on the type of stem cell. An embryonic stem cell can theoretically turn into every cell type – grow into an entire person. But there are also many types of stem cell that are already dedicated to being one type of tissue, like bone-marrow stem cells that can turn into various blood components. For stroke repair neuronal stem cells (NSC) are used.

The reason stroke is likely to be an early application is because after stroke the brain attempts to repair itself by recruiting naturally occurring NSC to rebuild lost pathways and restore function. This process is part of what is called neural plasticity (which also includes the brain’s ability to adapt its function to new tasks). So the ability to recruit stem cells for repair functions is already present – adding more NSC should therefore provide more raw material and help the repair process. If a large volume of brain is lost due to stroke it is likely that raw material will be in short supply, and replacing it will aid in repair.

In fact early research with rats has shown that introducing NSC after stroke does improve recovery. But so far it has not improved brain volume (or reduced volume loss) after stroke. The leading hypothesis is that this lack of increased brain volume is due to the fact that the transplanted NSC do not have anything to keep them in place until they have had a chance to be recruited – to make connections and become part of the brain architecture. It’s like having a pile of bricks to repair a collapsed section of building, but having no way to get the bricks to where they need to go.

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Apr 10 2008

Design, Evolution, and more Semantic Nonsense from ID Proponent, Michael Egnor

The one utility of the Evolution News and Views blog of the Discovery Institute is that it frequently demonstrates that ID proponents do not understand science and logic (or they simply don’t care, or some combination of the two). Dr. Michael Egnor is especially adept at demonstrating this critical lack of understanding, and he’s done it again. His most recent post lays out a few of the classic ID misdirections and misconceptions.

In response to my post in which I pointed out that the question is not whether there is design in nature but whether or not their is top-down (intelligent) design or bottom-up (evolved) design. Egnor argues:

No. Design is always the result of intelligent agency — by definition. It’s always top-down. Design is a mental act. Complexity can arise without intelligent design, but complexity is not the same thing as design. All design arises by intelligent agency, because that’s how design is defined. Consider the definition of design:

He then pulls the classic desperation maneuver of someone who is relying upon a semantic misdirection as if it were a logical argument – quoting a dictionary definition; as if a colloquial definition is relevant to the science. Egnor is presenting the typical “design gambit” of the ID crowd. They start with the premise that there is “design” in nature – but they don’t define design operationally or scientifically. Then they use a colloquial definition of design – that it implies an intelligent agent – and conclude that by definition life was designed by an intelligent agent. By using this purely semantic argument they bypass the actual scientific question – is the end product of life on earth the result of purposeful intelligence or did it emerge through blind natural processes?

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Apr 09 2008

Intelligent Design Is Not Science

Published by under Creationism/ID

There – I said it. The meme lives.

In response to my blog post about Intelligent Design (ID), Jason Rosenhouse, who writes the excellent Evolution Blog, wrote an entry taking exception to the fact that I wrote that the primary scientific criticism of ID is that it is not science. He acknowledges that this claim is true – ID is not science – but he is concerned about framing the criticism of ID in this manner because it allows ID defenders to say that we are unfairly “expelling” ID from science. Rather he thinks we should focus on the specific claims of ID (irreducible complexity, etc) and explain scientifically why they are not valid. Below in my response which I posted in his comments.

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Apr 08 2008

Brain Dead

It is often said of Paris Hilton that she is famous for being famous. Well, Zack Dunlap might have her beat – he is famous for not being dead.

In November 2007 Zack Dunlap was involved in a serious 4-wheel off-road biking accident, a roll-over resulting in severe head injury. He was flown to a nearby hospital where he was treated by trauma surgeons. His condition was critical. At 36 hours after his accident the doctors taking care of Zack feared that he might be brain dead. As Zack was a registered organ donor, they wanted to perform a confirmatory test so that if brain death were confirmed, the process of organ donation could begin.

A PET scan was performed at 36 hours. PET scanning (technically referred to as Technetium-99m hexamethylpropyleneamineoxime brain scan) is a measure of blood flow to the brain. Zack’s doctor, Leo Mercer, showed his parents the scan – his brain was entirely black. No blood flow. This was sufficient to meet criteria for brain death. The process of organ donation began.

About four hours later, while the family was saying their goodbye’s, Zack moved his foot in response to his cousin rubbing a knife blade along his foot. His responsiveness was confirmed by squeezing his nail-bed – he moved his arm with clear purpose. The diagnosis of brain death was set aside, and the process of organ donation was stopped, Zack was returned to full care and he slowly recovered. Zack’s story came up in the news again recently following a TV interview in which he said that he was doing OK.

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Apr 07 2008

Another Attack on Free Speech and a Science Blogger

Kathleen Seidel runs the neurodiversity blog – a science blog dedicated to autism and related issues. She is an outspoken critic of the “mercury militia” – those who claim that autism spectrum disorder is caused by mercury and/or vaccines. Recently she has been the subject of a subpoena to present all of her financial records and communication related to her website. The subpeona was issued by Clifford Shoemaker who is the attorney for plaintiffs Rev. Lisa Sykes and Seth Sykes against Bayer and other companies based upon the claim that vaccines caused their child’s autism. The subpeona was issued within hours of Kathleen writing a blog entry critical of Shoemaker.

Read the subpeona. I can tell you as a blogger, this is meant to be intimidating and to have a chilling effect on anyone who would dare express a controversial opinion inconvenient to this attorney and the misguided cause he represents. The consensus of the legal blogosphere is that it is without merit and represents an abuse of the subpoena privilege. Kathleen has written her own motion to quash the subpoena, and her motion will likely succeed.

This incident is a disturbing milestone in the shrillness of the autism/vaccine controversy. Those arguing for a connection are evolving more and more into an almost religious cult. Last week on Larry King Live actress Jenny McCarthy, who believes her son’s autism was caused by vaccines, shouted down the scientists who were calmly trying to discuss the scientific facts. Her husband, actor Jim Carrey, chimed in to support the notion that there is a conspiracy to hide the truth from the public.

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Apr 04 2008

Crop Circle Madness

Published by under UFO's / Aliens

I am away this week filming the pilot for The Skeptologists. For NeuroLogica this week I am updating and editing some previous essays that I have written. This one was originally published in my Weird Science column in July 2005.

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Several years ago a “crop circle” (actually a crop square) appeared in Martha Bailey’s cornfield in New Milford, CT. Her field is surrounded by a 7-foot-tall fence of chicken wire and wood. Overnight, in the middle of the field, a “perfect” square of flattened down corn appeared. According to Martha, “Everything was secure, the gates were locked, [so] it had to be something that touched down and flattened it.”

By something, she probably meant an extraterrestrial landing ship. Rather than looking for simpler explanations-like, say, someone climbing a chickenwire fence-believers in crop circles often posit visits from aliens or other paranormal explanations. And, perhaps fueled by pop-culture references like the 1999 M. Night Shyamalan movie Signs , the ranks of believers are growing. For the last couple of decades, mainly in English-speaking nations, summer brings with it an increasing number of ever-more-elaborate pictures made in large fields of wheat and other crops. Crop circle season exactly coincides-amazingly-with the end of school and the beginning of summer vacation.

Crop circles began appearing in England in the early 1980s. At first they were little more than giant simple circles in wheat fields. Over the years they have become more intricate and complex. Many recent crop circles resemble beautiful spirograph-like pictures. Over time, the circles spread from England to America, Australia and other English-speaking countries. They later spread to other European lands and, recently, into Asia as well.

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Apr 03 2008

Levitating Frogs and Free Energy

I am away this week filming the pilot for The Skeptologists. For NeuroLogica this week I am updating and editing some previous essays that I have written. This one was originally published in my Weird Science column in June 2005.

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When I was a child some of my favorite toys were simple magnets. I was fascinated by the way they could push or pull on each other at a distance with an invisible force. It was like magic. Energy itself, all types of energy, seems like magic. Physicists, performing almost like stage magicians (nothing up their sleeves), recently delighted in showing off how they could levitate frogs using superconducting magnets.

It’s no wonder that mysterious energies play a central role in so much of the science of the weird. Many gurus and mystics claim they can heal by simply manipulating “life energy.” There is also no shortage of con artists and the self-deluded who claim they have found the secret of limitless free energy. Simply inserting the word “energy” into any claim, no matter how ridiculous, will give it the appearance of cutting-edge science.

Shortly after the discovery of electromagnetism, while it was still cutting-edge science, Anton Mesmer claimed to have discovered “animal magnetism,” a new force that he could detect and manipulate to “mesmerize” his subjects. Benjamin Franklin, considered an expert of his day in the electrical force, was asked to head a commission to investigate Mesmer, and he definitively showed the claims to be nothing but delusion.

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Apr 02 2008

UFO’ and the Argument from Ignorance

Published by under UFO's / Aliens

I am away this week filming the pilot for The Skeptologists. For NeuroLogica this week I am updating and editing some previous essays that I have written. This one was originally published in my Weird Science column in February 2005.

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I once saw a UFO. That is, I saw an object in the sky I couldn’t identify. Chances are you have too, probably more than once. What I saw were lights in a large “V” shape, moving silently, too slow to be a plane, moving out of view after about 10 minutes. Was it a flying saucer, an alien spacecraft, a time-traveling psychic Bigfoot, or perhaps something more prosaic-something boring?

There are thousands of reported UFO sightings each year, and in this digital age you can easily find numerous pictures and video clips on the internet. Does this mean we are being visited by alien spacecraft? Probably not.

After more than half a century of fascination with flying saucers, there has yet to emerge a single piece of credible evidence that we are being visited by aliens. There isn’t one unambiguous photograph or video that holds up to scientific scrutiny, not one piece of physical evidence. No smoking saucer.

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