Posts Tagged ‘Lancet’

Fighting Fatigue

February 28, 2016

Fighting Fatigue is the fourth chapter in Jo Marchant’s “Cure:  A Journey Into the Science of Mind Over Body.” The key idea here is that the mind plays an important role in fighting fatigue.  It is worthwhile noting that many performance enhancing drugs, such as amphetamines, modafinil, and caffeine, work by influencing the central nervous system, not the muscles themselves.  A fairly recent healthy memory blog post, “Marathon Mind:  How Brain Training Could Smash World Records” obviously makes the same point.  However, what was missing from that blog post was the notion of a central governor.  The chapter documents extensive research showing that the no matter how hard we exercise, the body always takes the precaution to maintain a healthy reserve.  Presumably there is a central governor that controls this.  The question is whether this central governor can be persuaded, or fooled, to tap into some of this reserve.

Elite cyclists when given a pill or drink they believe is a performance enhancer can cycle on an average 2-3% faster.  Psychologist Chris Beedle suggests this is because the placebo increases their optimism and self-belief that persuades the central governor to free up more resources.  Another placebo expert  Fabrizio Benedetti concluded in a paper on fatigue that “a placebo may act as a cue signaling the central governor to inhibit its brake.”

This presence of a central governor might also explain why interval training, which consists of short bursts of high intensity exercise interspersed by recovery periods works so well.  According to sports physiologist Tim Noakes, who formulated the idea of a central governor, regular  sprints that push us close to our limit of maximum performance don’t just increase physical fitness, they also retrain the brain.  They teach the central governor that pushing ourselves that far was okay, so next time it’ll be safe to push ourselves a little bit further.

Chronic Fatigue Syndrome (CFS) is one of the most controversial conditions in medicine.  Its prognosis is extremely poor with trials that followed patients for up to five years concluding that the recovery rate is just 5%.  CFS is also known as myalgic encephalopathy (ME), although not everyone agrees that these are the same conditions.

To treat CFS and ME an approach was developed called graded exercise therapy (GET) that is intended to work as an ultra-gentle form of interval training.  Cognitive Behavioral Training (CBT) was combined with GET to bring the mind further into the treatment protocol.  This approach alarmed many patient groups who developed an alternative approach called adaptive pacing theory (APT).  The apparent belief of the APT group is that this was a real disease unaffected by the mind, and that people needed to learn to live with this illness.

A large five year study was conducted by Peter White of St. Barthlolomew’s Hospital and his colleagues that included 641 patients.  They were divided into four groups.  A control group that just received routine medical care.  The other groups received this standard care plus CBT, GET, or APT.  This study was published in he journal “Lancet” in 2011.  It reported the APT was completely ineffective. GET and CBT were both moderately helpful, reducing fatigue and disability scores more than the other two groups.  22% of the patients recovered after a year in the CBT and GET groups compared to just 7-8% in the other two groups.  Although this might not look impressive, it showed that GET and CBT were the best treatments available and that recovery from the condition is possible.

The  patient groups remained unimpressed and complained to the Journal.  the Journal answered with a strong endorsement of the research.  Patient groups remain unimpressed.  Apparently they like to believe what they believe and reject scientific evidence.

Syndrome E

November 27, 2015

In the recent healthymemory blog post, “A Single Shifting Mega-Organism,” Syndrome E (E stands for evil) was briefly discussed.  Syndrome E was developed to describe the atrocities, mass-killings, genocides such as the holocaust and the killings by ISIS.  The neurosurgeon Itzhak Fried describes these atrocities as examples of Syndrome E.   He defined the following seven symptoms of Syndrome E:

Compulsive repetitive violence
Obsessive beliefs
Rapid desensitisation to violence
Flat emotional state
Separation of violence from everyday activities
Obedience to an authority
Perceiving group members as virtuous

Having decided that neuroscience has come a long way since his original paper in 1997 (Syndrome E in The Lancet, Volume 150, No. 9094, p1845-1847) Fried  organized a conference in Paris earlier this year to revisit the concept.  Highlights of this conference were published in the New Scientist, November 14-20, 2015 in a feature by Laura Spinney.

Fried’s theory starts with the assumption that people normally have an aversion to harming others.  If this is correct, the higher brain overrides this instinct in people with Syndrome E.  So how might this occur.

The lateral regions of the prefrontal cortex (PFC) are sensitive to rules from the newer parts of the brain.  The medial region of the PFC receives information from the limbic system, a primitive part of the brain that processes emotional states and is sensitive to our innate to preferences.  An experiment using brain scanning was designed to put these two parts of the brain in conflict.  Both these parts of the PFC were observed to light up.  People followed the rule but still considered their personal preference showing that activity in the lateral PFC overrode the personal preference.  The idea here is in the normal brain the higher brain overrides signals coming from the primitive brain.  However, in the pathological brain with Syndrome E, the primitive brain prevails.

Fried suggests that people experience a visceral reaction when they kill for the first time, but some become rapidly desensitized.  And the primary instinct not to harm may become more easily overcome when people are “just following orders.”  Unpublished research using brain scans has shown that coercion makes us feel less responsible for our actions.  Although coercion can cause people to take extraordinarily actions (see the healthy memory blog post “Good vs. Evil”), there are individuals who are predisposed to violence who are just awaiting an opportunity.

Unfortunately, the question remains as to how to prevent people from joining such radicalized groups.  Research in this area is just beginning and much more needs to be done (See the healthy memory blog post,”Why DARPA is studying stories”). Being a neuroscientist, it is not surprising that Fried thinks  that we should use our growing neuroscientific knowledge to identify radicalization early, isolate those affected and help them change.  We wish him, and hopefully many others in this effort.

What is not mentioned in this article is that it can be advantageous for one group to adopt Syndrome E to take from or to take advantage of another group.  Consider North America.  Syndrome E was involved in vacating Native American lands for Europeans.  Moreover, up until the Civil War, blacks were enslaved and slavery was a key component of the economy of the United States.  I sometimes ponder how would North America been settled by Europeans had we the moral and ethical standards of today.

© 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.

Truth Decay

November 11, 2012

Truth Decay is the title of an intriguing and important article in the New Scientist.1 The author writes that when his grandfather was in dental school he learned that there were 48 chromosomes in a human cell. This was regarded as an established fact. But in 1956 Joe Hin Tjio and Albert Levan discovered using an improved and more accurate technique that there were only 46 chromosomes in a human cell.

It is the nature of science that facts change. Scientometrics is the field that studies how these facts change. The rate of change will likely surprise you. Thierry Poynard and his colleagues measured the churning of facts in two medical fields in which they specialized. Cirrhosis and hepatitis are two liver diseases. They took almost 500 articles in these fields from over a period of 50 years and gave them to a panel of experts to review. Each expert needed to rate each paper as to whether it was factual, out-of-date, or disproved.2 They discovered that 45 years after publication, 50% of journal articles had effectively decayed. They concluded that these articles had a 45 year “half-life.” Another study came to the same conclusion in a review of studies on surgery.3

The above studies were extremely pain-staking to conduct, so another method is used, and that is how long it takes for researchers to stop citing the average paper in the field. This technique is not as good as the failure to cite a paper does not necessarily indicate that the findings of the paper are no longer true. It could be that there are more recent and up to date papers, or that the journal’s focus has moved on to other topics. Nevertheless, this technique does provide an approximation. A study of Physical Review journals found that the half-life in physics is about 10 years.4 Half-lives also vary as a function of publication formats for different fields. In a study of scholarly books, physics has a different half-life (13.7 years), economics (9.4 years), which is longer than half lives of mathematics, psychology, and history.5 However, in journal articles, as opposed to scholarly books, the frontiers of hard science are overturned more rapidly than the frontiers of the social sciences.

The estimates of half lives and the rates of turn over in different publications and in different fields, although interesting, are not the main point here. The main point is that facts change and they change rapidly. For many years the Prostate Specific Antigen (PSA) was strongly recommended for all men over a certain age. Now it is only recommended for high risk groups and even then, only after consulting with their physician. I have been through many different ideal food groups in my life. At one time dairy products were supposed to be nature’s most perfect food. At another time the US had four basic food groups. Then there was a food pyramid that underwent multiple changes. Now there are five food groups. Advice on the consumption of fatty foods, carbohydrates and many other things change.

The purpose of this blog post is not to discredit science. At any given time, science provides the best facts for that time. But science is in constant flux, and what is factual today might not be factual at some future date. So remember that some of what you learned during your formal education might not be true today. This underscores the importance of lifelong learning, and lifelong learning fosters healthy memories.

1Arbesman, S. (2012). Truth Decay. New Scientist, 22 September, 37-39.

2Annals of Internal Medicine, Vol 136, p.888).

3The Lancet, vol 350, p.1752.

4Arxiv.org/abs/physics/0407137.

5College and Research Libraries, vol 69, p 356.

© Douglas Griffith and healthymemory.wordpress.com, 2012. 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.