Posts Tagged ‘Francis Bacon’

Understanding the Science of Elusive Health Risks

January 6, 2017

The title of this post is the subtitle of “Getting Risks Right” a book by an American epidemiologist and cancer researcher Geoffrey C. Kabat. He is a senior epidemiologist at the Albert Einstein College of Medicine.  Understanding these health risks is an extremely difficult task and Kabat makes a strong effort to assist us in executing this task.

The Preface asks the question “Why do things that are unlikely to harm us get the most attention?’  The simple answer is that science takes time and moves slowly, but people want quick answers.  The popular press publishes apparent answers that are a long way from being validated.

The first chapter is titled, “The Illusion of Validity and the Power of ‘Negative Thinking,’ and begins with the following quote from Francis Bacon:  “It is the peculiar and perpetual error of human understanding to be more moved and excited by affirmatives.
The root of all superstitions is that men observe when things hit but not when they miss; and commit to memory the one and forget to pass over the other.”

Chapter 2 describes the fundamentals of studies in the area of public health.  Ioannidis’s landmark article “Why Most Published Research Findings are False” (PLOS Medicine, 2, 3124. Doi:101371/journal pmed, 0020124, 2005) has been cited in several previous healthy memory posts.  The consensus among epidemiologists and statisticians is one of general agreement.  But most people remain ignorant of the situation.  The only article in the popular press of which HM is aware is Why Most Published Research Findings are False” (PLOS Medicine, 2, 3124. Doi:101371/journal pmed, 0020124, 2005).  Kabat discusses additional scientific difficulties in conducting scientific research in the area of health.  Please read his book to understand the relevant issues.

However, health research has additional difficulties because here the science is embedded in a society that is highly attuned to the latest potential or breakthrough.   Kabat writes, “Findings from rudimentary studies often are reported as if they were likely to be true when, in fact, most research findings are false or exaggerated, and the more dramatic the result, the less likely it is to be true.”  Later he writes, “Reports of exaggerated findings can, in turn, give rise to ‘information cascades’—highly publicized campaigns that can sow needless alarm and lead to misguided regulation ad policies.  These difficulties are thoroughly aired in Chapter 3.

The final four chapters of the book discuss 4 areas of research.  Chapter 4 explores the question of whether exposure to radio frequency energy causes brain cancer.  The issue, whether the worldwide adoption of a novel technology within a short time span could be causing a fatal disease.  Kabat documents the extensive research carried out over two decades provides no strong or consistent evidence to support this possibility.

Chapter 5 explores the main lines of preoccupation with “endocrine disrupting chemicals” in the environment hypothesis.  Although this certainly was a legitimate concern, Kabat documents how false ideas based on poor data got enormous attention.  He explains how to make sense of a bitter controversy that is currently raging in the scientific and regulatory communities in Europe and the United States.

Chapter 6 describes a little-known success story.  By linking a long-standing enigmatic disease in the Balkans to dietary exposure to a toxic herb that has been used in traditional cultures throughout history.  Research on aristolochic acid contained in certain varieties of the herb Aristolochia has  led to new insights on the carcinogenic process as well as highlighting the threat posed by the woefully inadequate regulation of thousands of products marketed as “dietary supplements.”  More than half of Americans use these products to the tune of $32 billion a year.  Unfortunately, naive consumers
wrongly believe that the government requires manufacturers to report all adverse effects and that the FDA must approve supplements before they are sold.  Few consumers of supplements are aware of the implications of the Dietary Supplements and Health Education Act (DSHEA), passed by Congress is 1994 with strong support from the supplements  industry and its political allies.  By defining herbal supplements and botanicals as “dietary supplements,” DSHEA excluded them from the more rigorous standards used in regulating prescriptions and even over-the-counter drugs.  By not making herbal supplements and botanicals subject to testing, US citizens are being put at risk.  This point is underscored by the following quote from Simon Singh and Edzard Ernst :  “Just because something is natural does not mean that it is good, and just because something is unnatural does not mean that it is bad.  Arsenic, cobra poison, nuclear radiation, earthquakes, and the Ebola virus can all be found in nature, whereas vaccines, spectacles, and artificial hips are all man-made.”  In this context HM would like to comment on the labeling of Genetic Modified Organisms (GMOs) as being bad.  To the contrary, they might be the only option for feeding an increasingly growing population.  The also offer the prospect of both better tasting and affordable products.

Chapter 7 recounts another success story, the long-standing question of what causes cervical cancer led, over a period of thirty years, to the identification of a small number of highly specific carcinogenic subtypes of the humanpapillomavirus (HPV).  The persistent infection with one or more of these subtypes is necessary to cause the disease.  This knowledge has led to the development of vaccines that have the potential to virtually eliminate cervical cancer as well as to fundamental new knowledge about how the virus evolved to cause cancer.

Kabat comes to the following conclusion, “the need for a more nuanced and realistic view of science, which acknowledges the enormous challenges, promotes skepticism toward widely circulated but questionable ides, and at the same time pays attention to what science can achieve at its best.

At this point please indulge HM in a personal story.  When he was working, he received a call from a representative of his insurance company.  This representative encouraged an annual checkup to include the prostate specific antigen test (PSAT).  For decades this had been a standard recommendation to men of my age.  However, HM tries to keep up with the literature.  He had read that urologists, the individuals most knowledgeable about the benefits of this test, had changed this long-standing recommendation.  Now the test is recommended only in certain high risk patients, and then, only after consulting with a physician.  However, it took another year before the rest of the medical community followed the lead of the urologists.

© Douglas Griffith and healthymemory.wordpress.com, 2016. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content.

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Understanding Beliefs

August 3, 2015

Understanding Beliefs is a book by Nils J. Nilsson in The MIT Press Essential Knowledge Series.  Perhaps a better title for the book would be “How We Should Believe,”  the reason for this should become clear by the end of this post.  Nilsson is one of the founders of artificial intelligence, and putting the concept of belief into computer science is quite valuable.

He does not work entirely  in the domain of artificial intelligence as he notes contributions from psychologists and neuroscientists.  He invokes Kahneman’s concepts of System One and System Two processes that have been discussed previously in the healthy memory blog.  System One processes run off more or less automatically.  System Two processes are more in the vein of what is regarded as thinking and require mental effort.  Our beliefs are processed automatically through System One and there is little evidence of additional brain activity..  When information contradicts our beliefs, the brain becomes active and if not immediately revoked, System 2 and effortful processing is engaged to deal with the conflicting belief.

Nilsson discusses his own beliefs.  He does not believe that we ever have contact with an external world.  Rather we form concepts or beliefs based on the sensory inputs from an external world and the subsequent cognitive activity.  Moreover, these beliefs are weighted in terms of probabilities.  Nothing is certain.  That is, there are no beliefs with values of 0.0 or 1.0, regardless of how strongly the belief or disbelief is felt.   My views are identical.  These views are common among scientists and philosophers.  Here are some exemplary quotes:

“Objects” do not exist independently of conceptual schemes  We cut up the world into objects when we introduce one of another scheme of description.”  Hilary Putnam, philosopher.

“There was no way to hook up ideas with things…because ideas—mental representations—do not refer to things; they refer to other mental representations.”  Louis Menand, author, referring to thoughts of the philosopher C.S. Pierce.

“There is no quantum world.  There is only an abstract physical  description.  It is wrong to think that the task of physics is to found out how nature is.  Physics concerns what we can say about nature.”  Niels Bohr, physicist.

“The physicist constructs what he terms the physical world, a concept which arises from a peculiar combination of certain observed facts and the reasoning provoked by their perception.”  Robert Lindsay and Henry Margenau, physicists.

Nilsson advocates the scientific method as being the gold standard for confirming or rejecting beliefs.   When beliefs are modified, probabilities are adjusted, but beliefs are no entirely confirmed or discounted.  Near the beginning of the eleventh century, al_Haytham, an Islamic scholar who lived in Basra and Cairo, wrote the Book of Optics,which included a theory of vision and a theory of sight.  According to one authority, “Ibn al-Haytham was the pioneer of the modern scientific method.  His book changed the meaning of the term “optics” and established experiments as the norm of proof in the field.  His investigations were not based on abstract theories, but on experimental evidence, and his experiments were systematic and repeatable.  Unlike the Greeks, in his theory of vision rays of light came from the objects seen rather than from the eyes that see them.

Some of the European contributors to the development of the scientific method are Robert Grosseteste (c. 1125-1253), Roger Bacon (c. 1214-1294), Galileo (1564-1642), Francis Bacon (1561-1626), Rene Descartes (1596-1650), and, of course, Isaac Newton(1643-1727).

Problems arise when the problem is how to change erroneous beliefs.  The default for people is what they already believe, and much effort is involved in changing beliefs.  Moreover, we tend to seek out information that confirms rather than disconfirm our beliefs.  The internet has exacerbated this problem.  Different sites cater to different beliefs and we tend to search for information that confirms our beliefs.

The psychologist Daniel T. Gilbert describes two separate mental activities for processing a new piece of information, comprehension and assessment.  Assessment involves comparing  what is comprehended with other information.  It is much easier to reject than to accept information that does not correspond with existing beliefs.  Moreover, people do not like to suspend judgment.  Closure is preferred.  However, doubt us a valuable defense against belief traps.

Great minds can embrace doubt  The physicist Richard Feynman said, “I can live with doubt and uncertainty and not knowing—I think it’s much more interesting to live not knowing that to have answers that might be wrong.  I have approximate answers and possible beliefs and different degrees of certainty about different things but I’m not absolutely sure of anything and there are many things I don’t know anything about.”

I fear that if we contrasted what  Feynman said with the typical individual on the street, we would find that most people have definite opinions about many things the know nothing about.  And many of these beliefs fly in the face of accepted scientific opinion—evolution for example.

Nilsson believes that the scientific method offers the best way discovered so far to invent  and evaluation beliefs.  And he believes that the best antidote to belief traps is to express our belies to the reasoned criticisms of others.  But as you should remember from the previous healthy memory blog post on belief, that beliefs are extremely difficult to change.  The viability of Nilsson’s  remedies will be discussed in the next healthy memory blog post.

© Douglas Griffith and healthymemory.wordpress.com, 2015. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content.