Scientific consensus

Steven Novella from Neurologica posted on the value of scientific consensus and how it differs from the logical fallacy of an argument from authority. Some selected quotes:

"... we advocate rigorous and robust scientific methodology as the best way of understanding nature, we trust this process to some degree. We understand there can be fraud or sloppy studies, but generally if the research of others is all pointing toward one answer, we trust that research and its conclusions.

... science is complex, and few people can master more than a fairly narrow range of scientific expertise. And so outside our area of expertise (which is all of science for non-scientists) the best approach to take, in my opinion, is a hybrid approach – first, try to understand what is the consensus of scientific opinion.

... those interested in science will want to understand the evidence directly and how it relates to the consensus. But at the same time it must be recognized that a non-expert understanding of the evidence is a mere shadow of expert understanding.

... it is extreme hubris to substitute one’s frail non-expert assessment of a detailed scientific discipline for the consensus of opinion of scientific experts."

Novella continues to also point out that consensus of opinion is not always right – it is just usually right. He addresses important issues and I would recommend reading his whole post.

Increasing brain plasticity through diet

The Independent reports on research that indicates that brain plasticity is improved by the availability of magnesium to the brain.

"The international team of researchers from MIT, Tel Aviv University (TAU), Tsinghua University in Beijing and University of Toronto found an increase in 'brain magnesium enhances both short-term synaptic facilitation and long-term potentiation (LTP) and improves learning and memory functions.'"

Said Inna Slusky, PhD:

"We are really pleased with the positive results of our studies, but on the negative side, we've also been able to show that today's over-the-counter magnesium supplements don't really work. They do not get into the brain."

Supplements not being effective, the alternative is eating magnesium-rich foods such as spinach, almonds, cashews, soybeans, oatmeal, halibut and even chocolate pudding.

See the actual study in Neuron.

Why consumers buy snake oil

Steven Novella from Neurologica reports on a behavioural economics analysis of why people buy snake oil (and modern supplements) even when its ineffectiveness is apparent. It boils down to: "What can I lose?" I've previously blogged on this in Snake oil for rusty snakes and quoted this delightful remark by author Terry Pratchett just after being diagnosed with early onset Alzheimers:

"Some of them wanted to sell me snake oil and I’m not necessarily going to dismiss all of these, as I have never found a rusty snake."

Here are some selected quotes from Novella's discussion of research by Werner Troesken:

"... people still wanted to buy patent medicines, even after their previous experience with such products resulted in failure.

... Troesken’s basic model – medicines do not work, consumers judge them solely on whether or not they work, and consumers correctly perceive that they do not.

... consumers felt that they had little to lose and the world to gain, leading to repeated experimentation with, and even high demand for, patent medicines."

Other factors for the continued popularity of snake oil, as pointed out by Novella, include the effect of false positives (false anecdotal "evidence") and the placebo effect. Of particular interest is that the very success of science based medicine leads to people living longer and their age related ailments creating a larger market for snake oil.

Novella makes the point that, based on the above, it cannot be expected that market forces will result in better and more effective health products, or even keep entirely worthless or even harmful health products from the marketplace.

Some genetic and epigenetic correlates of vulnerability and resilience

Hat tip to Andy Smarick from Flypaper for alerting me to a fascinating article by David Dobbs in The Atlantic. It relates to the interaction between genetic and environmental factors to produce either vulnerable or resilient phenotypes based on the same risk allele. The specific risk allele is one for ADHD and externalizing behaviours.

Dobbs explained as follows:

"Most of us have genes that make us as hardy as dandelions: able to take root and survive almost anywhere. A few of us, however, are more like the orchid: fragile and fickle, but capable of blooming spectacularly if given greenhouse care. So holds a provocative new theory of genetics, which asserts that the very genes that give us the most trouble as a species, causing behaviors that are self-destructive and antisocial, also underlie humankind’s phenomenal adaptability and evolutionary success. With a bad environment and poor parenting, orchid children can end up depressed, drug-addicted, or in jail—but with the right environment and good parenting, they can grow up to be society’s most creative, successful, and happy people."

Related: Can the right kinds of play teach self-control?

Music training helps with dyslexia?

By now it is known that the so-called Mozart Effect is a myth. Just listening to music does not have the specific cognitive benefits claimed.

There has, however, been some research suggesting that music training and playing a musical instrument does have cognitive benefits. It is known that lack of phonemic awareness is one of the most important determinants of dyslexia.

Prof. Nina Kraus, Hugh Knowles Professor of Neurobiology, Physiology and Communication Sciences at Northwestern University, recently claimed that music training enhances brainstem sensitivity to speech sounds. She added:

"Playing an instrument may help youngsters better process speech in noisy classrooms and more accurately interpret the nuances of language that are conveyed by subtle changes in the human voice."

According to ScienceDaily, her and other neuroscientists' research suggest that music education can be an effective strategy in helping typically developing children as well as children with developmental dyslexia or autism more accurately encode speech. Something to think about for schools who have scrapped music training.

but, a contrary view that came to my attention later:

Music therapy no help to dyslexics.

Related: Children who grow up in noisy homes may have lower verbal abilities.

Repeat after me: "Teaching to learning styles does not work"

I despair of ever weaning gullible teachers of the nonsense of teaching to learning style. Educational consultants are not going drop learning style theory from their repertoire while there is good money to be made. Thank your to Donald Clark and Wil Thalheimer for the following from the Association of Psychological Science:

"We conclude therefore, that at present, there is no adequate evidence base to justify incorporating learning-styles assessments into general educational practice. Thus, limited education resources would better be devoted to adopting other educational practices that have a strong evidence base, of which there are an increasing number. However, given the lack of methodologically sound studies of learning styles, it would be an error to conclude that all possible versions of learning styles have been tested and found wanting; many have simply not been tested at all." (p. 105)

Reference: Pashler, H., McDaniel, M., Rohrer, D., & Bjork, R. (2008). Learning styles: Concepts and evidence. Psychological Science in the Public Interest, 9, 105-119.