Latest Threads
Greatest Threads
Home » Discuss » Journals » Jim__ » Archives Donate to DU
Advertise Liberally! The Liberal Blog Advertising Network
Advertise on more than 70 progressive blogs!
Jim__'s Journal - Archives
Posted by Jim__ in Science
Sun Sep 04th 2011, 06:35 PM
I was basing my posts on my reading of the article and just thinking about what it was saying. So, since you were claiming that all my issues are resolved in the experiment and didn't provide any links, I looked for myself. It seems that Libet's understanding of consciousness and free will is closer to mine than the article implied. The online article about Libet and his experiments states that Libet's beliefs included the phrase in the title to the post.

But, further, experiments conducted in 2009, found that the reaction Libet was measuring was not indicative of a decision having been made (source):

One of the most frequently visited pages on Conscious Entities is this account of Benjamin Libet’s remarkable experiments, which seemed to show that decisions to move were really made half a second before we were aware of having decided. To some this seemed like a practical disproof of the freedom of the will – if the decision was already made before we were consciously aware of it, how could our conscious thoughts have determined what the decision was? Libet’s findings have remained controversial ever since they were published; they have been attacked from several different angles, but his results were confirmed and repeated by other researchers and seemed solid.

However, Libet’s conclusions rested on the use of Readiness Potentials (RPs). Earlier research had shown that the occurence of an RP in the brain reliably indicated that a movement was coming along just afterwards, and they were therefore seen as a neurological sign that the decision to move had been taken (Libet himself found that the movement could sometimes be suppressed after the RP had appeared, but this possibility, which he referred to as ‘free won’t ‘, seemed only to provide an interesting footnote). The new research, by Trevena and Miller at Otago, undermines the idea that RPs indicate a decision.

Two separate sets of similar experiments were carried out. They resembled Libet’s original ones in most respects, although computer screens and keyboards replaced Libet’s more primitive equipment, and the hand movement took the form of a key-press. A clock face similar to that in Libet’s experiments was shown, and they even provided a circling dot. In the earlier experiments this had provided an ingenious way of timing the subject’s awareness that a decision had been made – the subject would report the position of the dot at the moment of decision – but in Trevena and Miller’s research the clock and dot were provided only to make conditions resemble Libet’s as much as possible. Subjects were told to ignore them (which you might think rendered their inclusion pointless). This was because instead of allowing the subject to choose their own time for action, as in Libet’s original experiments, the subjects in the new research were prompted by a randomly-timed tone. This is obviously a significant change from the original experiment; the reason for doing it this way was that Trevena and Miller wanted to be able to measure occasions when the subject decided not to move as well as those when there was movement. Some of the subjects were told to strike a key whenever the tone sounded, while the rest were asked to do so only about half the time (it was left up to them to select which tones to respond to, though if they seemed to be falling well below a 50-50 split they got a reminder in the latter part of the experiment). Another significant difference from Libet’s tests is that left and right hands were used: in one set of experiments the subjects were told by a letter in the centre of the screen whether they should use the right or left hand on each occasion, in the other it was left up to them.

There were two interesting results. One was that the same kind of RP appeared whether the subject pressed a key or not. Trevena and Miller say this shows that the RP was not, after all, an indication of a decision to move, and was presumably instead associated with some more general kind of sustained attention or preparing for a decision. Second, they found that a different kind of RP, the Lateralised Readiness Potential or LRP, which provides an indication of readiness to move a particular hand, did provide an indication of a decision, appearing only where a movement followed; but the LRP did not appear until just after the tone. This suggests, in contradiction to Libet, that the early stages of action followed the conscious experience of deciding, rather than preceding it.

Of course people disagree with the results of this experiment too - discussed on the referenced page. The point being that these issues are far from resolved; and one type of decision making process is not necessarily representative of all types of decision making processes.
Read entry | Discuss (0 comments)
Posted by Jim__ in Religion/Theology
Thu Nov 25th 2010, 02:05 PM
First, Dembski mentioned a paper (I believe it is this paper) to counter the argument that the placement of the optic nerve in front of the retina is poor design. The paper talks about the way in which the Müller cells, in the front of the retina, serve as an optical filter that improves vision. I'm not sure how this relates to the placement of the optic nerve. Are the Müller cells, in some way, part of the optic nerve and if the optic nerve were behind the retina these cells wouldn't be in front of it? Or, is Dembski arguing that there would be less oxygen available to the retinal cells if the optic nerve were behind the retina (the paper does not make this point)? I'm wondering because a standard trick of creationists is to claim some new fact changes the way things have to be viewed - in this case Dembski is arguing that the optic nerve in front of the retina is an advantageous design. Does anyone know if that's true? I don't believe the paper explicitly talks about the optic nerve - but if the Müller cells are a part of this nerve, then the paper agrees with him.

The abstract from the paper:

Although biological cells are mostly transparent, they are phase objects that differ in shape and refractive index. Any image that is projected through layers of randomly oriented cells will normally be distorted by refraction, reflection, and scattering. Counterintuitively, the retina of the vertebrate eye is inverted with respect to its optical function and light must pass through several tissue layers before reaching the light-detecting photoreceptor cells. Here we report on the specific optical properties of glial cells present in the retina, which might contribute to optimize this apparently unfavorable situation. We investigated intact retinal tissue and individual Müller cells, which are radial glial cells spanning the entire retinal thickness. Müller cells have an extended funnel shape, a higher refractive index than their surrounding tissue, and are oriented along the direction of light propagation. Transmission and reflection confocal microscopy of retinal tissue in vitro and in vivo showed that these cells provide a low-scattering passage for light from the retinal surface to the photoreceptor cells. Using a modified dual-beam laser trap we could also demonstrate that individual Müller cells act as optical fibers. Furthermore, their parallel array in the retina is reminiscent of fiberoptic plates used for low-distortion image transfer. Thus, Müller cells seem to mediate the image transfer through the vertebrate retina with minimal distortion and low loss. This finding elucidates a fundamental feature of the inverted retina as an optical system and ascribes a new function to glial cells.

the rest of the paper ...

My second thought is on the question of morality as it was raised in the debate. My interpretation of Dembski's moral claim is that "it's good if God says it's good." IOW, morality is completely determined by God, there is no other standard. He then claims that atheists have no basis for morality.

I agree with the beginning of Hitchens response - morality comes from the evolutionary process. But then he says that morality is determined by the Socratic method. I think he's completely wrong there.

I agree that morality is determined by the evolutionary process. Whatever cultures survived, then, ipso facto, their morality was valid. But, this does make morality somewhat arbitrary - we should do what we feel is right because our innate feeling tend to be correct; but, we don't always know what behaviors lead to a better probability of survival.

This raises difficult issues about in-group/out-group behavior. My take on this is that cultural/moral behaviors of other groups, behaviors that don't directly impact the survival of our group, are acceptable. The more different behaviors that human groups have, the better over-all chance for the survival of the species.

I think Hitchens needs to work on his position on morality. If morality is evolutionarily based, then it does not come from the Socratic method. The Socratic method can make adjustments to our behavior, but it really cannot dictate visceral feelings. And, to my mind, morality is largely based on visceral feelings.
Read entry | Discuss (0 comments)
Posted by Jim__ in Editorials & Other Articles
Sun Dec 27th 2009, 01:24 PM
From The Nation:

"If you don't have enough evidence to charge someone criminally but you think he's illegal, we can make him disappear." Those chilling words were spoken by James Pendergraph, then executive director of Immigration and Customs Enforcement's (ICE) Office of State and Local Coordination, at a conference of police and sheriffs in August 2008. Also present was Amnesty International's Sarnata Reynolds, who wrote about the incident in the 2009 report "Jailed Without Justice" and said in an interview, "It was almost surreal being there, particularly being someone from an organization that has worked on disappearances for decades in other countries. I couldn't believe he would say it so boldly, as though it weren't anything wrong."

It wasn't that long ago that we read of "the disappeared" in other countries. From Buzz Flash:

For some 30 years, the Argentine women known as the Madres (Mothers) de La Plaza de Mayo have marched every Thursday in front of the Presidential Palace of Argentina. They gather in memory of their children and grandchildren, who were among the estimated 30,000 people who disappeared during "Operation Condor." Another 50,000 people were murdered.

One of the Madres (Mothers) de la Plaza de Mayo displaying a photo of her son who was one of an estimated 30,000 "disappeared" during "Operation Condor."

"Operation Condor" reached its peak in the 1970s. With assistance from the United States, and the support and knowledge of Henry Kissinger, five of the southern cone South American nations conducted a campaign of unspeakable torture and killing against their own citizens.

Of course, it will never get that bad here. Never.

Read entry | Discuss (4 comments)
Posted by Jim__ in Science
Fri Nov 14th 2008, 09:23 AM
Watch the video. About 3 to 4 minutes into the video, Dr. Healey discusses a 2004 report from the Institute of Medicine (IOM). She states that in that report, the IOM discourages research into whether or not there are subgroups susceptible to serious harm from vaccines. The reason the IOM does not want this studied is that they believe that this type of information will discourage people from getting vaccines. In this report, the IOM acknowledges that there may well be such susceptible groups.

If you have looked into this at all, you are familiar with the Hannah Polling case in which the US government conceded that vaccine contributed to her autism. Her father is a doctor, her mother was a nurse (now a lawyer). Her case was exceedingly well documented, which is partially why the government conceded. Listen to an interview of her father.

I think Dr Healey has it right. The government fears that any admission of a connection between autism and vaccines will discourage people from getting their children vaccinated; so, they deny any possible connection. The numbers that I see with respect to this is that the danger is to about 1 in 10,0000 people. That's a small number (not likely to show up as statistically significant in most studies) and that's why Dr. Healey asks for studies to be done on an identified subgroup, e.g. children who have autism whose parents connect it to receiving a vaccine.
Read entry | Discuss (2 comments)
Posted by Jim__ in Skepticism, Science and Pseudoscience Group
Wed Oct 01st 2008, 04:15 PM
A couple of thoughts and some questions. Sokal's paper is a difficult read for anyone who is not conversant with the topics he's writing about. I've read through his paper a number of times, and I'm sure I haven't identified all the nonsensical parts. Social Text is not a refereed journal, and did not vouch for the accuracy of the articles it printed. It also printed his article in a special edition called "Science Wars" - the article seemed pertinent to the topic. Should they have printed the article? What is the standard to be used? And does this standard apply universally?

The answers to those questions are important. If publishing nonsense in a non-refereed journal condemns all of post-modernism to ridicule, what are we to say of a number refereed physics journals that may have published nonsense (most physicists aren't sure). It's not as famous as the Sokal Hoax, but the Bogdonoff Affair is fairly well-known. The jargon in their papers published in refereed physics journals is impenetrable to all but a few:

For example, here's the beginning of Igor Bogdanoff's paper "Topological Origin of Inertia":

The phenomenon of inertia - or "pseudo-force" according to E. Mach <1> - has recently been presented by J. P. Vigier as one of the "unsolved mysteries of modern physics". Indeed our point of view is that this important question, which is well formulated in the context of Mach's principle, cannot be resolved or even understood in the framework of conventional field theory.

Here we suggest a novel approach, a direct outcome of the topological field theory proposed by Edward Witten in 1988 <3>. According to this approach, beyond the interpretation proposed by Mach, we consider inertia as a topological field, linked to the topological charge Q = 1 of the "singular zero size gravitational instanton" <4> which, according to <5>, can be identified with the initial singularity of space-time in the standard model.

It goes on to discuss the supposed connection between N = 2 supergravity, Donaldson theory, KMS states and the Foucault pendulum experiment, which he claims "cannot be explained satisfactorily in either classical or relativistic mechanics". If you know some physics you'll find this statement odd. The Foucault pendulum behaves exactly the way classical mechanics predicts: it is a standard textbook exercise!

It's not only post-modernism that has a problem with jargon. The lesson from the Sokal Hoax may well be that we may never know what the hell someone else is actually saying.
Read entry | Discuss (0 comments)
Greatest Threads
The ten most recommended threads posted on the Democratic Underground Discussion Forums in the last 24 hours.
Visitor Tools
Use the tools below to keep track of updates to this Journal.
Random Journal
Random Journal
Home  |  Discussion Forums  |  Journals  |  Campaigns  |  Links  |  Store  |  Donate
About DU  |  Contact Us  |  Privacy Policy
Got a message for Democratic Underground? Click here to send us a message.