Dr Caroline Leaf – Scientific heresy

Screen Shot 2015-03-30 at 7.54.04 pm

Imagine that this Easter, the guest speaker at your church stands up from the pulpit and calmly mentions during the sermon that Jesus wasn’t really buried in a tomb, but was kept by his disciples in a house until he recovered enough from his wounds to go on his merry way.

What would you think of that speaker? Would you smile and nod, or even shout an ‘amen!’, buy their book, and encourage your pastor that they should be invited back again?

One would hope that there would be a polite but resounding outcry. Even if the rest of the message was perfect, you wouldn’t want someone to come back to your pulpit if they couldn’t get the basics of their subject right, even if they were considered a popular speaker or self-declared expert.

Dr Caroline Leaf is a communication pathologist and self-titled cognitive neuroscientist. Dr Leaf preaches every day from both physical pulpits all over the globe, and a virtual pulpit through the power of Instagram and Facebook.

Dr Leaf used her position of social media prominence today to share this little jewel, “The brain cannot change itself; you, with your love power and sound mind, change your brain.”

Um … that’s not true … at all … in any way.

For a start, the most prolific period for brain development is actually pre-birth, and then the first year of life. But foetal brains don’t have their own thoughts. It’s not like the movie “Look Who’s Talking” inside the average uterus. The brain of an unborn baby is growing and changing at an exponential rate without any thoughts to guide them [1].

Screen Shot 2015-03-30 at 9.32.16 pm

Number of synapses per constant volume of tissue as a function of pre- and postnatal age. (Stiles, J. and Jernigan, T.L., The basics of brain development. Neuropsychol Rev, 2010. 20(4): 327-48 doi: 10.1007/s11065-010-9148-4)

 

In our adult years, our brain still continues to develop. But that development isn’t dependant on our thought life. Significant consolidation of our brain’s neural pathways occur when we’re asleep [2], but our thought life isn’t active during sleep.

Model of sleep stage-specific potentiation and homeostatic scaling. Gronli, J., et al., Sleep and protein synthesis-dependent synaptic plasticity: impacts of sleep loss and stress. Front Behav Neurosci, 2013. 7: 224 doi: 10.3389/fnbeh.2013.00224

Model of sleep stage-specific potentiation and homeostatic scaling. (Gronli, J., et al., Sleep and protein synthesis-dependent synaptic plasticity: impacts of sleep loss and stress. Front Behav Neurosci, 2013. 7: 224 doi: 10.3389/fnbeh.2013.00224)

Indeed, real cognitive neuroscientists have shown that our stream of thought is simply a tiny fraction of our overall neural activity, a conscious glimpse of the brains overall function [3-5]. So you don’t change your brain at all. “You” can’t, because it’s your brain’s directed activity which causes the growth of new synaptic branches to support it, all of which is subconscious.

Therefore, suggesting that our brain can only change with our conscious control is patently false, and so clearly against the most fundamental principles of neuroscience that such a claim is the neuroscientific equivalent of saying that Jesus didn’t die on the cross, he just swooned.

Dr Leaf has committed scientific heresy.

At this point, supporters of Dr Leaf often suggest that she wasn’t speaking literally, but metaphorically. She didn’t really mean that the brain can’t change itself, just that our choices are really important.

Somehow I doubt that. Dr Leaf wasn’t being metaphorical when she claimed that her patients in her research projects grew their intelligence when they “applied their minds”:
“Now with a traumatic brain injury, basically IQ generally goes down around twenty points because of the kind of damage with traumatic brain injury. Well her IQ was 100 before the accident, it was 120 after the accident. So here with holes in her brain, and brain damage, she changed … she actually increased her intelligence. Now I’m pretty convinced at this stage, cause I’ve been working … besides her I’ve been working with lots and lots of other patients, seeing the same thing, when these students applied their mind, their brain was changing, their academic results were changing.” [6]

Dr Leaf believes that your mind can literally change your brain. It was the subject of her entire TEDx talk in February.

It sounds innocent enough until you consider the broader implications of this way of thinking – those with brain damage haven’t recovered fully because they just haven’t applied their minds enough. The same for those with learning disabilities or autism, ADHD, Downs syndrome, cerebral palsy, dyslexia, or any other neurological disorder … because you only need to “apply your minds” to change your brain. “You have a powerful mind. You have a sound mind. You have a mind that is able to … to achieve what you’re dreams are. You are as intelligent as you want to be.” [6]

Or, in other words, don’t blame it on your brain if you’re intellectually disabled, mentally ill, or vacuous. You simply haven’t applied your brain well enough. Stop sitting around and think better.

As a church, we can, and should, be doing a lot better for those amongst us who suffer from neurological and mental disorders. It starts by being more judicious with who is allowed at that privileged position of the pulpit. We need to be eliminating scientific heresy from the pulpit, not clapping and shouting ‘amen!’

References

  1. Stiles, J. and Jernigan, T.L., The basics of brain development. Neuropsychol Rev, 2010. 20(4): 327-48 doi: 10.1007/s11065-010-9148-4
  2. Gronli, J., et al., Sleep and protein synthesis-dependent synaptic plasticity: impacts of sleep loss and stress. Front Behav Neurosci, 2013. 7: 224 doi: 10.3389/fnbeh.2013.00224
  3. Baars, B.J., Global workspace theory of consciousness: toward a cognitive neuroscience of human experience. Progress in brain research, 2005. 150: 45-53
  4. Baars, B.J. and Franklin, S., An architectural model of conscious and unconscious brain functions: Global Workspace Theory and IDA. Neural Netw, 2007. 20(9): 955-61 doi: 10.1016/j.neunet.2007.09.013
  5. Franklin, S., et al., Conceptual Commitments of the LIDA Model of Cognition. Journal of Artificial General Intelligence, 2013. 4(2): 1-22
  6. Leaf, C.M., Ridiculous | TEDx Oaks Christian School | 4 Feb 2015, 2015 TEDx, 20:03. https://http://www.youtube.com/watch?v=yjhANyrKpv8

The TEDx Users Guide to Dr Caroline Leaf

On the 4th of February 2015, Dr Caroline Leaf gave her debut TED presentation, at TEDx Oakes Christian School, California.

Most TED watchers wouldn’t have heard of her before, but Caroline Leaf is a well-known name in western Christendom. She has spoken from pulpits on every continent. She’s authored one of the best selling books in the Christian market and has her own TV show on cable in the US. She’s followed by more than one hundred thousand people on Facebook, and she’s even run her own conference, with another in the pipeline. She’s a mega-star in the Christian world.

So who is this woman with the stiletto-heels and slick presentation? What was her training and background? How did she make it to the TEDx stage?

This aim of this post is to provide some context and background for those in the TED universe who have seen Dr Leaf’s TEDx presentation, and want some more information in assessing her TEDx debut, and indeed, the global Caroline Leaf phenomenon.

This review will be in four main parts: first I will give some basic information on Dr Leaf, I will compare Dr Leaf’s claims in her TEDx presentation to her published research results and some basic neuroscience, and lastly I’ll outline Dr Leaf’s general work and it’s accuracy compared to current science.

  1. WHO IS DR LEAF?

Dr Caroline Leaf was born and raised in South Africa, where she completed her school education and went on to attain the following degrees:

  1. Bachelors of Science (Logopaedics) – University of Cape Town 1985
  2. Masters in Audiology and Speech Pathology – University of Pretoria 1990
  3. Doctor Philosophiae (Communication Pathology) – University of Pretoria 1997 (http://drleaf.com/assets/files/DrCarolineLeaf_CurriculumVitae1.pdf)

Officially, Dr Leaf is qualified as a communication pathologist (which is a specialized combination of Speech Pathology and Audiology – see also: http://www.hpcsa.co.za/Uploads/editor/UserFiles/downloads/speech/slh_education_training_insitutions.pdf)

Dr Leaf worked for a number of clinics and school boards as a communication pathologist in the few years following the completion of her PhD (http://drleaf.com/assets/files/DrCarolineLeaf_CurriculumVitae1.pdf).

Dr Leaf has written a number of articles for publication in minor journals (see http://drleaf.com/assets/files/DrCarolineLeaf_CurriculumVitae1.pdf). Three of her papers were published in a small Medline indexed journal, “The South African Journal of Communication Disorders”. These are:

  1. “Mind-Mapping approach (MMA): a culture and language “free” technique”, 1993 (http://www.ncbi.nlm.nih.gov/pubmed/8047932)
  2. “The development of a model for geodesic learning: the geodesic information processing model”, 1997 (http://www.ncbi.nlm.nih.gov/pubmed/9819969)
  3. “An alternative non-traditional approach to learning: the metacognitive-mapping approach”, 1998 (http://www.ncbi.nlm.nih.gov/pubmed/10472179)

The journal happened to be edited by her supervisor and co-author, Dr Brenda Louw (see http://www.debunkingdrleaf.com/goodies), though I’m sure the selection of her articles for this journal was purely on merit.

Dr Leaf states on a number of occasions that she is a “cognitive neuroscientist”, and “a scientific and Biblical expert in the power of the human mind”.Leaf Cognitive NeuroscientistAbout Dr Leaf

This is despite the fact that Dr Leaf:

  1. does not have formal qualifications in neuroscience,
  2. has not worked at a university as a neuroscientist,
  3. has not worked in any neuroscience research labs,
  4. has not published any papers in neuroscience journals, and
  5. has not had any formal theological training.

Given the weight of evidence, Dr Leaf would be better described as an academic speech pathologist and lay preacher rather than a cognitive neuroscientist.

  1. DR LEAF’S RESEARCH RESULTS

Throughout her TEDx presentation, Dr Leaf repeatedly made reference to the results of her own research, suggesting that her pioneering work resulted in radically improved outcomes for the students involved in her research, and that her work with students one-on-one and through teacher education profoundly changed the learning of every student in her various programs.

For example, she said, “Well her IQ was 100 before the accident, it was 120 after the accident. So here with holes in her brain, and brain damage, she changed … she actually increased her intelligence. Now I’m pretty convinced at this stage, cause I’ve been working … besides her I’ve been working with lots and lots of other patients, seeing the same thing, when these students applied their mind, their brain was changing, their academic results were changing.”

Later she stated, “I wasn’t sure if this was going to have the same impact cause until this point I’d been working one on one. Well I’m happy to tell you that we had the same kind of results … The minute that the teachers actually started applying the techniques, we altered the trend significantly.”

And also, “I stand up here saying this with conviction because I have seen this over and over and over in so many different circumstances … in this country I worked in Dallas for three years in charter schools, and we found the same thing happening.”

However, her published results differ significantly from her claims.

The first research that Dr Leaf spoke of was of the sixteen-year-old girl who was the victim of a motor vehicle accident. This particular girl was Dr Leaf’s prime patient. The case study of this patient was presented in Dr Leaf’s unpublished Masters thesis, and was discussed in more detail in Dr Leaf’s paper, “Mind-Mapping approach (MMA): a culture and language “free” technique” [1], though it should be noted that no statistics were published in this paper, and on the third page of the article, Dr Leaf admitted that the result could actually have been spontaneous recovery rather than her own intervention.

Dr Leaf did further work within a number of schools for her PhD research. Dr Leaf compared the academic results for three schools for the years 1991 and 1992 to the results for 1993, during which she introduced her mind mapping approach (MMA). Generally, the results for 1993 were better than the results for 1992, which seems to indicate that Dr Leaf’s MMA training was effective. However, the results from 1991 to 1992 were already improving without her input [2: p182]. The difference in average marks between 1991 and 1992 was 1.76%, while the difference between 1992 and 1993 (the introduction of Dr Leaf’s MMA) was only 2.19%. If Dr Leaf’s program really was the cause of that improvement, then her program only resulted in a 0.43% improvement on average.

I have reproduced Dr Leaf’s original graph of the average overall results obtained in her PhD study. While Dr Leaf’s original graph makes her data look spectacular, when appropriately rescaled, the data looks quite ordinary.

Leaf1997 Thesis overall academic trends

DrLeafThesisResult_Rescaled

At best, Dr Leaf’s program gave the already positive momentum of the students a gentle nudge.

However, it should be noted that her program may have also hindered some students. Dr Leaf notes in her analysis: “The results obtained indicate that in general the academic trend in the three primary remedial schools was altered with the introduction of the MMA methods in 1993. Furthermore, it appears that the most positive response occurred in phase one (grades 1 and 2, standard 1). A positive response also occurred in phase two (standards 2-4) but this change was just outside the significance level. Phase three (standard 5), by contrast, experienced negative effects with the introduction of the MMA methods.” [2: p181]

So to summarise, according to Dr Leaf’s own data, there was no clear benefit derived from her MMA program.

Dr Leaf then discussed her work in a number of charter schools that she performed in Dallas. This was part of testing of a program called the Switch On Your Brain 5-step learning process.

Dr Leaf claims that, “The Switch On Your Brain with the 5-Step Learning Process® was assessed in a group of charter schools in the Dallas. The results showed that the students’ thinking, understanding and knowledge improved across the board. It was concluded that The Switch On Your Brain with the 5-Step Learning Process® positively changed the way the students and teachers thought and approached learning.” http://drleaf.com/about/dr-leafs-research/

However, there has been no independent research into Dr Leaf’s Switch On Your Brain learning program or even the Geodesic Information Processing Theory, the theory Dr Leaf devised and on which the Switch On Your Brain program is based.

Dr Leaf published her own internal research into the program on her website. The project was a two year program involving teachers and students at a group of four schools in the Advantage Academy group in Dallas, Texas. This involved working with more than 150 teachers and 2000 students.

Despite her glowing self-assessment, Dr Leaf’s own published numbers suggest that the program is ineffective, or quite possibly a hindrance. For example, the graph below demonstrates the qualitative analysis of “content mastery” (which the paper describes as a combination of knowledge and understanding) for reading across all grades from 3rd to 12th, compared with the results from the previous year before the Switch On Your Brain was implemented. Dr Leaf omits a basic statistical analysis, but just by looking at the similarity of the scores, these results are more likely to be a chance effect, except for the 12th grade, where the previous cohort of students increased dramatically, where as the Switch On Your Brain cohort got slightly worse.

Screen Shot 2015-02-02 at 11.27.37 pm

Rather than blame her program, Dr Leaf simply shifts the blame to the teachers: “The few cases where we see drops can be linked to teacher knowledge, attitude and skills and is diagnostic.”

The full research paper that Dr Leaf published is available at http://drleaf.com/assets/files/Web-page-AA-research-project-1.pdf if you wish to review the results for yourself.

The ineffectiveness of Dr Leaf’s program may be for many reasons, but I believe one is that it is built on a theory that relies on mind-mapping. Dr Leaf renamed her version of mind-mapping “The Metacog”, though it’s clear from her early academic work [1] that the Metacog and the Geodesic Information Processing Model [3] were based on the work of Tony Buzan. Buzan’s concept of mind-mapping has been used across multiple professional fields [4] and remains a valuable resource for brainstorming or gathering thoughts in a visual way. However, modern research (including a controlled trial within a primary school classroom environment) shows that mind mapping is a poor tool for learning [5-8].

  1. DR LEAF’S IRONIC INSPIRATIONS

Dr Leaf openly contradicts herself throughout her presentation, failing to realise that the stories she shared of her own patients disproved her vacuous inspirational memes.

Our biology affects each and every one of us. Our mind is a function of our brain. Our mind is to our brain as our breath is to our lungs. Put simply, without our brain, we would have no thoughts. If the structure and function of specific networks in our brains are altered, this changes our thinking. This is confirmed in everyday life – when someone suffers a brain injury or a stroke and they sustain damage to their brain, they suddenly lose the function of some, or all of their mind or body. Trans-cranial Magnetic Stimulation, Trans-cranial Direct Current Stimulation, metabolic states, prescription medications, illicit drugs, or everyday drugs like caffeine or alcohol have all been proven to change the subjects mental state through changes to the function of their brain. Any suggestion that our brain does not control our mind is simply ludicrous.

Clearly then our biology does control our psychology. Real cognitive neuroscientists have shown that our stream of thought is simply a tiny fraction of our overall neural activity, a conscious glimpse of the brains overall function [9-11], like the tachometer is for the engine in your car. Thus, our mind does not change our brain at all. Rather, it is our brain’s directed activity causing the growth of new synaptic branches to support it, something which the brain does without the function of conscious thought from the time when we were embryos.

Dr Leaf actually confirms this fact through her stories of her brain injured patients. After all, if “the mind is separate from the brain but influencing the brain”, then how could those victims of acquired brain injury lose cognitive function after their injury? If it were true that “each and every one of us is not a victim of our biology. We are a victor over and above our biology. We control our brain, our brain does not control us”, then how could those people with damage to their brains from strokes suddenly lose function?

The fact that Dr Leaf’s patients lost their mental or cognitive function because of damage to their brains directly contradicts her insistence that our brain and our mind are separate, and that our brain does not control our mind.

  1. FUNDAMENTALS OF DR LEAF’S OTHER TEACHING

Considered altogether, Dr Leaf’s teaching boils down to a few fundamentals;
* Thought is the main driving force that controls every other aspect of our lives (and our physical world).
* We have full control over our thoughts.
* Thought causes stress.
* Stress is directly responsible for nearly all serious physical and mental illness.
* Therefore thought causes the vast majority of human disease, making thoughts toxic, and
* If toxic thoughts cause disease, “detoxing” thoughts will cure or prevent disease.

On first inspection, each individual postulate doesn’t seem so bad. However, when fully considered and taken to their natural conclusions, they veer into conjecture and pseudoscience, as evidenced by Dr Leaf’s published works and public appearances.

For example, Dr Leaf states in her books:

“Thoughts influence every decision, word, action and physical reaction we make.” [12: p13]
“Our mind is designed to control the body, of which the brain is a part, not the other way around. Matter does not control us; we control matter through our thinking and choosing.” [13: p33]
“DNA actually changes shape according to our thoughts.” [13: p35]

On Facebook and in interviews, this translates to:

“Our genetic makeup fluctuates by the minute based on what we are thinking and choosing.” 27/9/2014
“The toxic thoughts in our minds become physical baggage in our brain, which literally cause brain damage.” 5/12/2014, 27/10/2014 and 7/10/2014
“Your mind will adjust your body’s biology and behaviour to fit with your beliefs.” 21/6/2014

“SID ROTH: But when you told me that we could change our genes I wish every doctor in the world would understand this cutting edge research because, you know, you go to a doctor and say your cholesterol was high, and they say, well, exercise, change your diet, but it could be your genes and there’s nothing you can do, so take this medicine that will have a zillion side effects. But you say, according to the latest brain research, if you follow what Jesus said you can change your genes. That’s just so amazing.
DR. LEAF: I know. It is phenomenal. If you think of it, it’s logical too, Sid …”
http://youtu.be/Uhbt_XOZTdA?t=50s. Full transcript: http://donate.sidroth.org//site/DocServer/IS571Transcript_Leaf.pdf?docID=2941

Dr Leaf draws her erroneous conclusions from the poor interpretation of poor evidence. For example, one of Dr Leaf’s favourite factoids is her statement that “Research shows that 75 to 98 percent of mental, physical and behavioral illness comes from one’s thought life.” [13: p33] Dr Leaf’s sources for this statement include, among others, an article that not only doesn’t mention the figure she attributes to it, but also directly contradicts her fundamental premise [14], and the misleading paraphrasing of an already dubious quote from a pseudoscientific author [15].

Dr Leaf also has a number of pet theories which betray her preference for pseudoscience, the main one being her assertion that the heart is actually a mini-brain that has dedicated cognitive functions. For example, in her books, she says,

“Your heart is in constant communication with your brain and the rest of your body, checking the accuracy and integrity of your thought life.   As you are about to make a decision, your heart pops in a quiet word of advice, well worth listening to, because when you listen to your heart, it secretes the ANF hormone that gives you a feeling of peace.” [12: p62, 13: p127]

Dr Leaf directly quotes the work of an organisation called HeartMath for her evidence that the heart acts as a mini-brain. Dr Leaf, via Heartmath, states that:
> The heart has a network of 40,000 neurons within it, called sensory neurites, which detect circulating hormones, neurochemicals, and sense heart rate and blood pressure,
> The heart secretes “neurotransmitters” and other hormones, which have an effect on the brain, such as atrial natriuretic factor, and oxytocin,
> The heart communicates with the brain and the rest of the body through neurological, biophysical, biochemical and “energetic” (ie: electromagnetic) means [16, 17].

HeartMath clarifies, “The heart’s brain is an intricate network of several types of neurons, neurotransmitters, proteins and support cells like those found in the brain proper. Its elaborate circuitry enables it to act independently of the cranial brain – to learn, remember, and even feel and sense.” [16]

So the “evidence” looks plausible on the surface, but absurd when considered in a broader biological context. For example, my heart may have 40,000 neurons, many of which are sensitive to circulating hormones, neurochemicals and which sense and feel, but then again, so does my rectum. Does my rectum have a mini-brain as well? Clearly not. The only brain you have is the one in your cranium. We do not think with our heart, our rectum, or any other body part.

A more in-depth rebuttal of Dr Leaf’s scientific claims can be found in my book: “Hold That Thought – Reappraising the work of Dr Caroline Leaf”, via Smashwords (https://www.smashwords.com/books/view/466848) or iTunes (https://itunes.apple.com/us/book/hold-that-thought/id908877288?mt=11).

SUMMARY

The opening question from Dr Leaf’s presentation at the 2015 TEDx Oaks Christian School was, “Can the mind change the brain?”

Clearly the answer is: “No, it can not.”

Others are welcome to disagree, but in my humble opinion, I suggest that Dr Leaf is a pseudoscientist, and that her appearance on the TEDx stage is not based on scientific acumen, but on popularity and reputation, which in turn, is based on slick self-promotion and an availability cascade (a self-reinforcing process by which an idea gains plausibility through repetition).

Dr Leaf’s ideas may have popular approval, but TEDx is a vehicle for ideas worth spreading, not ideas that are popular. According to its guidelines, TEDx requests that pseudoscience be avoided, specifically stating, “TED and TEDx are platforms for showcasing and explaining genuine advances in science … Speakers should avoid the misuse of scientific language to make unsubstantiated claims.” (http://www.ted.com/participate/organize-a-local-tedx-event/before-you-start/tedx-rules)

Dr Leaf’s claims, that her research has significantly changed the lives of the students who were blessed to receive it, is simply not born out by any of her own published data – from her original case study through to her MMA project and her Switch On Your Brain program. Whatever the underlying reason … whether its hubris, naivety, or denial that’s driving her continued promotion of her own programs … her claims are baseless, and therefore an argument can be made that she breached the TEDx guidelines in presenting them, and indeed, she should never have been invited to deliver them from a TEDx stage in the first place.

The theme for the 2015 TEDx Oaks Christian School event was “Ridiculous”. I would argue that it was ridiculous that Dr Leaf promoted her research as life changing when in reality, it’s not much better than a placebo. It was ridiculous that Dr Leaf would share stories of the changes to the cognitive functioning of her patients from their brain damage and then claim that the brain does not influence the mind. It seems that Dr Leaf’s presentation certainly fitted their theme, although probably not in the way they intended. Lets hope for their sake that their “ridiculous” decision doesn’t effect their ability to host future TEDx presentations.

Of course, that’s just my opinion. What do you think, TEDx universe?

REFERENCES

  1. Leaf, C.M., et al., Mind-Mapping approach (MMA): a culture and language” free” technique. The South African journal of communication disorders. Die Suid-Afrikaanse tydskrif vir Kommunikasieafwykings, 1993. 40: 35
  2. Leaf, C.M., The Mind Mapping Approach: a model and framework for geodesic learning, in Department of Communication Pathology, Faculty of Arts1997, University of Pretoria: Pretoria. p. 266.
  3. Leaf, C.M., et al., The development of a model for geodesic learning: the geodesic information processing model. The South African journal of communication disorders. Die Suid-Afrikaanse tydskrif vir Kommunikasieafwykings, 1997. 44: 53
  4. Eppler, M.J., A comparison between concept maps, mind maps, conceptual diagrams, and visual metaphors as complementary tools for knowledge construction and sharing. Information Visualization, 2006. 5(3): 202-10
  5. Farrand, P., et al., The efficacy of the `mind map’ study technique. Medical Education, 2002. 36(5): 426-31 doi: 10.1046/j.1365-2923.2002.01205.x
  6. Wickramasinghe, A., et al., Effectiveness of mind maps as a learning tool for medical students. South East Asian Journal of Medical Education, 2007. 1(1): 30-2
  7. D’Antoni, A.V., et al., Does the mind map learning strategy facilitate information retrieval and critical thinking in medical students? BMC Med Educ, 2010. 10: 61 doi: 10.1186/1472-6920-10-61
  8. Merchie, E. and Van Keer, H., Spontaneous Mind Map use and learning from texts: The role of instruction and student characteristics. Procedia – Social and Behavioral Sciences, 2012. 69: 1387-94
  9. Baars, B.J., Global workspace theory of consciousness: toward a cognitive neuroscience of human experience. Progress in brain research, 2005. 150: 45-53
  10. Baars, B.J. and Franklin, S., An architectural model of conscious and unconscious brain functions: Global Workspace Theory and IDA. Neural Netw, 2007. 20(9): 955-61 doi: 10.1016/j.neunet.2007.09.013
  11. Franklin, S., et al., Conceptual Commitments of the LIDA Model of Cognition. Journal of Artificial General Intelligence, 2013. 4(2): 1-22
  12. Leaf, C., Who Switched Off My Brain? Controlling toxic thoughts and emotions. 2nd ed. 2009, Inprov, Ltd, Southlake, TX, USA:
  13. Leaf, C.M., Switch On Your Brain : The Key to Peak Happiness, Thinking, and Health. 2013, Baker Books, Grand Rapids, Michigan:
  14. Cohen, S., et al., Psychological stress and disease. JAMA: the journal of the American Medical Association, 2007. 298(14): 1685-7
  15. Lipton, B.H., The biology of belief: Unleashing the power of consciousness, matter and miracles. 2008, Hay House, Inc:
  16. Rosch, P. Emotional balance and health. Science of The Heart: Exploring the Role of the Heart in Human Performance – An Overview of Research Conducted by the Institute of HeartMath 2013 [cited 2013, 16/7/2013]; Available from: http://www.heartmath.org/research/science-of-the-heart/emotional-balance-health.html.
  17. Rosch, P. Head-Heart Interactions. Science of The Heart: Exploring the Role of the Heart in Human Performance – An Overview of Research Conducted by the Institute of HeartMath 2013 [cited 2013, October 20]; Available from: http://www.heartmath.org/research/science-of-the-heart/head-heart-interactions.html.

Dr Caroline Leaf – It’s no joke

Screen Shot 2015-02-13 at 7.59.24 pm

So, stop me if you’ve heard this one … This guy walks into a bar, and says, “Owww, that bar is really hard.”

Ok, that was a bad joke. Hey, I’m no Robin Williams. Some people have the knack of being able to make people laugh in almost any situation. I can get a few laughs, but I’m not a naturally gifted comic.

Dr Caroline Leaf is a communication pathologist and a self-titled cognitive neuroscientist. She isn’t a comedian either.

Her post today was a light-hearted dig at giant lizards with a taste for organic free-range humans, or perhaps the fact that most people know being “all organic, gluten free” should be left to the sanctimonious foodies of San Francisco.

The other part of her post wasn’t meant to be funny, but certainly contained a healthy dose of irony. In trying to justify her bit of light comic relief, she posted another of her subtly erroneous factoids, this time claiming that, “Laughing 100-200 times a day is equal to 10 minutes of rowing or jogging!”

Not according to real scientists, who have worked out that laughing is actually the metabolic equivalent to sitting still at rest, while jogging or rowing burns between 6 to 23 times as much energy, depending on how fast you run or row [1].

That would mean that I would have to laugh for at least a whole hour a day (or about 700 times based on the average chortle) to be even close to the energy burnt by a light jog.

On the grand scale of things, this meme probably doesn’t really matter. These sort of factoids are thrown around on social media all the time, and it won’t make a big difference to the health and wellbeing of most people. But it does help establish a pattern. Dr Leaf habitually publishes memes and factoids that clearly deviate from the scientific truth, proving that Dr Leaf has become a cross between a science fiction author and life coach, not a credible scientific expert. From her social media memes to her TV shows, all of her teaching becomes tainted as untrustworthy.

While today’s meme may not be so serious, if Dr Leaf can’t get her facts straight, pretty soon the joke will be on her.

References

  1. Ainsworth, B.E., et al., 2011 Compendium of Physical Activities: a second update of codes and MET values. Med Sci Sports Exerc, 2011. 43(8): 1575-81 doi: 10.1249/MSS.0b013e31821ece12

Dr Caroline Leaf and dualism revisited

Screen Shot 2015-01-18 at 9.05.13 pm

Are we a body with a mind, or a mind with a body?

This may sound like a chicken-and-egg type of conundrum, but it’s a deep philosophical question. The concept of the separation of the mind from the body is known as dualism, and has been debated for centuries because the answer to that question then guides a lot of other philosophies and theories.

Dr Caroline Leaf is a communication pathologist and a self-titled cognitive neuroscientist. She believes that the body and brain are separate from the mind, which significantly influences her teaching. Take, for example, her social media meme-of-the-day today. She posted that, “The brain does not change itself… our MIND changes the brain”. If one assumes that the mind is separate from our brain, then its plausible that the mind influences the brain.

Except that it doesn’t. Our mind is a product of our brain, not a separate entity. Neurological damage from injuries or tumours, electrical stimulation of the brain in the lab, the effect of illicit drugs on the brain like LSD or marijuana, and everyday examples like the changes to our thinking under the influence of caffeine or alcohol, all prove that changes to the structure and function of the brain change thought patterns. It isn’t the other way around. Every brain changes itself too – the brain of an embryo or foetus undergoes massive changes but foetuses don’t have streams of conscious thought. Dr Leaf’s meme is scientifically misguided.

Perhaps what is more worrying is Dr Leaf’s use of scripture to try and justify her view that the mind and the brain are separate. To introduce her meme, Dr Leaf wrote, “Read Luke 16:19-31 to see that the mind is separate from the brain – this is God’s divine design.”

There are a number of scriptures that theologians use to discuss the biblical basis for the separation of the body and soul, but Luke 16:19-31 isn’t one of them. That passage is the parable of Lazarus and the rich man.

It says:

‘There was a rich man who was dressed in purple and fine linen and lived in luxury every day. At his gate was laid a beggar named Lazarus, covered with sores and longing to eat what fell from the rich man’s table. Even the dogs came and licked his sores.
‘The time came when the beggar died and the angels carried him to Abraham’s side. The rich man also died and was buried. In Hades, where he was in torment, he looked up and saw Abraham far away, with Lazarus by his side. So he called to him, “Father Abraham, have pity on me and send Lazarus to dip the tip of his finger in water and cool my tongue, because I am in agony in this fire.”
‘But Abraham replied, “Son, remember that in your lifetime you received your good things, while Lazarus received bad things, but now he is comforted here and you are in agony. And besides all this, between us and you a great chasm has been set in place, so that those who want to go from here to you cannot, nor can anyone cross over from there to us.”
‘He answered, “Then I beg you, father, send Lazarus to my family, for I have five brothers. Let him warn them, so that they will not also come to this place of torment.”
‘Abraham replied, “They have Moses and the Prophets; let them listen to them.”
‘“No, father Abraham,” he said, “but if someone from the dead goes to them, they will repent.”
‘He said to him, “If they do not listen to Moses and the Prophets, they will not be convinced even if someone rises from the dead.”’ (Luke 16:19-31, NIV)

I’m not sure exactly where the convincing proof of the separation of our mind and our body is found in this passage. This is a description of the afterlife, and in this parable, the rich man was very specific about memories (“I have five brothers …”) as well as physical sensations (“I am in agony in this fire”) and even parts of the body (Lazarus’s finger, his tongue). Jesus isn’t telling a story of how the mind is separate to the body, but of a different dimension in which the body and the mind are still together. This passage isn’t proof for the concept of dualism, but against it.

Dualism also has a number of fatal scientific and philosophical flaws, in particular that dualism is conceptually fuzzy, experimentally irrefutable, considers only the adult mind, and violates physics, in particular the law of conservation of energy.

So Dr Leaf bases her teaching on a scientifically and philosophically untenable concept and then attempts to use a scripture which refutes dualism in her attempt to support it. That’s audacious, but then to claim that it’s God’s divine design is, at best, a little brazen.

Dualism may be one of her fundamental philosophies, but I think Dr Leaf should review the basis for it, and possibly reconsider her reliance on it.

For a more in-depth discussion on Dr Leaf and dualism, please see my essay: Dr Caroline Leaf, Dualism, and the Triune Being Hypothesis

Dr Caroline Leaf and the obesity overstatement

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Caroline Leaf is on the nutritional warpath.

Our society isn’t the best when it comes to eating right. Fast food and junk food are more attractive options than fresh food, and nearly everyone knows it. Today, the internet is flooded with celebrity chefs and self-titled experts attempting to leverage some profit by advocating their own brand of diet or herb as the simple solution to what is a deceptively complex problem.

Dr Caroline Leaf is a communication pathologist and self-titled cognitive neuroscientist. In recent times she has also jumped on to the nutritional bandwagon, advocating organic gluten free recipes through food-selfies, and reposting Jamie Oliver quotes.

Today’s meme follows a similar line, where she has reposted an image which fits with her personal cognitive bias – a picture of french-fries in a cigarette packet, accompanied by the tag line, “THE OBESITY DEATH RATE IS OVERTAKING CIGARETTE SMOKING. Consume with caution”.

The image is a case study in overstatement. According to the most recent Global Burden of Disease data (currently 2010), the death rate associated with cigarette smoking is currently 91.4 per 100,000 population while the death rate associated with a high BMI is only 48.1 per 100,000 population. Even extrapolating the figures to the current year, the predicted rates would still be 89.1 vs 51.9 respectively, which are still a long way apart. On the current trends, obesity won’t overtake smoking as a global cause of death until 2055. So saying the obesity death rate is overtaking cigarette smoking is like saying that Christmas is coming – it’s technically true, but it’s still a long way off.

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There are a couple of reasons why deaths associated with obesity are rising while the deaths associated with cigarette smoking are falling. The most obvious is that cigarette smoking is decreasing, but treatments for smoking related illnesses are also concurrently improving, so less people are getting sick from cigarette smoking and those that do are less likely to die.

Of course, it’s no secret that more people, especially in the western world, are getting fatter. The old assumption was that obesity contributed to metabolic syndrome which then caused heart disease and type 2 diabetes and a concomitant rise in deaths. However, new evidence casts serious doubt over these assumptions.

In a meta-analysis of the association of mortality to BMI, Flegal, Kit, Orpana, and Graubard (2013) showed that overweight people have a slightly lower death rate than normal weight people, those with mild obesity have the same risk of death as normal weight people, and that the overall risk of all classes of obesity was small (relative risk 1.18 (95% CI, 1.12-1.25)). As a comparison, the risk of death from cigarette smoking is up to 2.66 (Shavelle, Paculdo, Strauss, & Kush, 2008)**.

The key to understanding this paradox is found in another meta-analysis, by Kramer, Zinman, and Retnakaran (2013) They showed that obesity and metabolic dysfunction are separate entities, with metabolically healthy obese people having the same risk of death as metabolically healthy people of normal weight (RR 1.19 (95% CI 0.98 to 1.38)) while metabolically unhealthy people with a normal weight had a risk three times that (RR 3.14 (95% CI, 2.36 to 3.93)).

So the key isn’t whether someone’s obese or not, the key is whether someone’s metabolically healthy or not (which is another blog for another time). According to the latest scientific evidence, the obesity death rate probably isn’t related to obesity after all.

Dr Leaf might be on the nutritional warpath with the right intentions, but her lack of expertise and willingness to fact-check is showing with every meme. If she wants to continue portraying herself as an expert in the area of food and nutrition, she needs to move away from her personal biases and start promoting proper science.

References

Flegal, K. M., Kit, B. K., Orpana, H., & Graubard, B. I. (2013). Association of all-cause mortality with overweight and obesity using standard body mass index categories: a systematic review and meta-analysis. JAMA, 309(1), 71-82. doi: 10.1001/jama.2012.113905

Kramer, C. K., Zinman, B., & Retnakaran, R. (2013). Are metabolically healthy overweight and obesity benign conditions?: A systematic review and meta-analysis. Ann Intern Med, 159(11), 758-769. doi: 10.7326/0003-4819-159-11-201312030-00008

Shavelle, R. M., Paculdo, D. R., Strauss, D. J., & Kush, S. J. (2008). Smoking habit and mortality: a meta-analysis. J Insur Med, 40(3-4), 170-178.

Graph data: Institute for Health Metrics and Evaluation (IHME). GBD Database. Seattle, WA: IHME, University of Washington, 2014. Available from http://www.healthdata.org/search-gbd-data. Accessed 15/1/2015

** This means that a smoker is more than twice as likely to die compared to a non-smoker, but an obese person’s risk is only about one fifth more likely to die compared to a person with a normal body mass index.

Dr Caroline Leaf: All scare and no science?

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On her social media feed today, Dr Leaf posted a meme implying that conventionally farmed food was toxic.

Dr Caroline Leaf is a communication pathologist and self-titled cognitive neuroscientist. Anyone who’s been following Dr Leaf will know from her frequent food selfies that she is an organic convert.

Dr Leaf is welcome to eat whatever she chooses, though not content to simply push her personal belief in organic foods, Dr Leaf is now actively criticising conventional food, publishing memes on her social media posts which imply that conventional produce is poisonous.

As I’ve written before, despite Dr Leaf’s blinding passion and quasi-religious zeal for organic foods, there is no evidence that organic food is any more beneficial than conventional food (Dangour et al, 2009; Bradbury et al, 2014). Indeed, there’s no magic to a healthy food lifestyle. Eat more vegetables. Drink more water. Conventional veggies and conventional water do just fine. Sage advice, even if it doesn’t lend itself to food selfies.

While organic zealots believe they have the high ground on the topic of food safety, the published science cuts through the hype. As noted by Smith-Spangler et al (2012), there is some evidence that there may be less pesticide residue on organically grown foods, but there is no significant difference in the risk of each group exceeding the overcautious Maximum Residue Limit.

Two points on the Maximum Residue Limit that are particularly important:

  1. The Maximum Residue Limit is extremely cautious, and most food tested is well below this already overcautious limit. The Maximum Residue Limit is set to about 1% of the amount of the pesticide that has no effect on test animals.   According to a recent survey of grapes done by Choice Australia, the amount of residue was well below the Maximum Residue Limit (about 1% of the Maximum Residue Limit on average) (Choice Australia, 2014). So on the average bunch of grapes in Australia, the pesticide residue is about one ten thousandth of the level that is safe in animals, and this pattern is the same across all conventional produce. Thinking in more practical terms, “a 68 kg man would have to eat 3,000 heads of lettuce every day of his life to exceed the level of a residue that has been proven to have no effect on laboratory animals … an 18 kg boy would have to eat 534 apples every day of his life to exceed a residue level that is not dangerous to laboratory animals. And an 18 kg girl would have to eat 13,636 kg of carrots every day of her life to exceed such a level.” (ecpa.eu, 2014)

    2. Organic foods have pesticides too. Granted, this is at lower levels than their conventional counterparts, but it’s there all the same (Smith-Spangler et al, 2012). I once had a lively discussion with an organic food zealot about the pesticides in organic farming. Her argument was that organic pesticides are safe because they’re “natural” poisons. So are arsenic, cyanide, belladonna and digitalis (foxglove), but why let the truth get in the way of ones opinion. Poisons are poisons whether they’re “natural” or not. The Maximum Residue Limit applies to organic foods just the same as conventionally farmed produce for that reason.

Another interesting thing … in the Choice survey, the organic grapes had no detectable pesticides, but so did conventionally farmed grapes bought at a local green grocer. So organic food zealots can’t claim that they have a monopoly on low pesticides in their foods.

Not that having lower pesticide residues means that organic foods are necessarily safer. Organically farmed produce has a higher risk of contamination from E. coli and other potentially toxic bacteria, depending on the farming method used (Mukherjee et al, 2007; Sample, 2011).

So to bring it all together, conventional produce has levels of pesticide residues so low that it would take an extra-ordinary feat of vegetarian gluttony to exceed a level that was still found to be non-toxic in animals. The risk to human health from conventional farming with pesticides is nanoscopic. Organic foods may have less pesticide, but they have a higher risk from enterotoxigenic bacteria.

Since there is nothing to fear from conventional foods, it seems irresponsible for Dr Leaf to promote the unscientific idea that conventional foods are poisonous. One wonders why Dr Leaf would engage in a campaign of fear against healthy, nutritious foods? Personal bias perhaps, although that doesn’t bode well for her credibility as an objective scientist. Another plausible reason could be marketing. Fear sells things, that’s Marketing 101. Gardner (2008) wrote, “Fear sells. Fear makes money. The countless companies and consultants in the business of protecting the fearful from whatever they may fear know it only too well. The more fear, the better the sales.”

Posts like today’s make Dr Leaf seem like all scare and no science. Publishing images with the skull and cross bones and the word “POISON” is certainly not attempting to allay anyone’s anxiety, and that fact that it‘s directly tied to a reminder of her upcoming book on food only makes shameless promotion all the more likely. I’m sure that a Godly woman of Dr Leaf’s standing wouldn’t stoop so low as to use fear and mistruth just to make better sales, but posts like today’s open her up to legitimate questions from others regarding her credibility and her motivation.

For her sake, I hope that she tightens up her future posts, and reconsiders her stance on the science of organic and conventional foods.

References

Bradbury, K.E., et al., Organic food consumption and the incidence of cancer in a large prospective study of women in the United Kingdom. Br J Cancer, 2014. 110(9): 2321-6 doi: 10.1038/bjc.2014.148

Choice Australia, 2014. <http://www.choice.com.au/reviews-and-tests/food-and-health/food-and-drink/groceries/pesticide-residues-in-fruit-and-vegetables.aspx&gt;

Dangour, A. D., Dodhia, S. K., Hayter, A., Allen, E., Lock, K., & Uauy, R. (2009). Nutritional quality of organic foods: a systematic review. Am J Clin Nutr, 90(3), 680-685. doi: 10.3945/ajcn.2009.28041

European Crop Protection Agency, 2014, <http://www.ecpa.eu/faq/what-maximum-residue-level-mrl-and-how-are-they-set>

Gardner, D., The science of fear: Why we fear the things we shouldn’t – and put ourselves in greater danger; 2008, Dutton / The Penguin Group, New York

Mukherjee, A., et al., Association of farm management practices with risk of Escherichia coli contamination in pre-harvest produce grown in Minnesota and Wisconsin. Int J Food Microbiol, 2007. 120(3): 296-302 doi: 10.1016/j.ijfoodmicro.2007.09.007

Sample, I., E coli outbreak: German organic farm officially identified. The Guardian, London, UK, 11 June 2011 <http://www.theguardian.com/world/2011/jun/10/e-coli-bean-sprouts-blamed>

Smith-Spangler, C., Brandeau, M. L., Hunter, G. E., Bavinger, J. C., Pearson, M., Eschbach, P. J., . . . Stave, C. (2012). Are organic foods safer or healthier than conventional alternatives? A systematic review. Ann Intern Med, 157(5), 348-366.

Dr Caroline Leaf, behaviour and genetic destiny

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Today on her Facebook feed, Caroline Leaf posted a quote which said, “Your behavior can and does dictate your genetic destiny”. Dr Caroline Leaf is a communication pathologist and a self-titled cognitive neuroscientist. In isolation, it sounds like she has found confirmation of her view that our thoughts and behaviour control the physical properties of our DNA (Leaf, 2013, p35).

However, I wanted to look at the quote in a broader context, because in the broader context, the quote still doesn’t confirm Dr Leaf’s teaching.

The quote comes from an American doctor, Sharon Moalem. Dr Moalem is obviously a smart man. According to Wikipedia, “Dr. Moalem is an expert in the fields of rare diseases, neurogenetics, and biotechnology. He is the author of the New York Times bestselling book ‘Survival of the Sickest’ and ‘How Sex Works’. Moalem has cofounded two biotechnology companies and is the recipient of 19 patents for his inventions in biotechnology and human health.” (http://en.wikipedia.org/wiki/Sharon_Moalem)

It’s not that Dr Moalem’s quote is wrong. In the book from which the quote is taken, Dr Moalem discusses the expression of genes (Moalem, 2014). There is no doubt that our behaviour affects the expression of genes. For example, when the body encounters a high level of dietary iron (ie: we eat a big juicy steak), a series of steps activates a gene to promote the production of ferritin, a protein that helps to carry iron in the blood stream (Strachan and Read, 2011, p375-6). These changes in genetic expression are mostly protective (for example, ferritin is used to keep toxic elemental iron from damaging our tissues). There are some behaviours that will override the body’s protection, for example, excessive exposure to UV radiation will eventually lead to skin cancer. But overall, the changes in genetic expression that our behaviour causes are protective, and do not adversely affect our health.

Unlike Dr Leaf, Dr Moalem does not promote the notion that our behaviour changes the genes themselves. Neither does he promote that our behaviour, in isolation, is the only modifier of our genetic expression. The quote that Dr Leaf used came from the second chapter of Dr Moalem’s book, “Inheritance: How Our Genes Change Our Lives, and Our Lives Change Our Genes”. Really, the title says it all. Our behaviour influences our genetic destiny, but our genes influence our behaviour just as much, if not more.

For example, small variations in the genes that code for our smell sensors or the processing of smells can change our preferences for certain foods just as much as cultural exposure. Our appreciation for music is often changed subtly between individuals because of changes in the structure of our ears or the nerves that we use to process the sounds. The genetic structure of the melanin pigment in our skin changes our interaction with our environment because of the amount of exposure to the sun we can handle. Our genetic destiny is also largely influenced by our environment, most of which is also beyond our choice (Lobo and Shaw, 2008).

So your behaviour can and does influence your genetic destiny, but your genetic destiny is more influenced by our genes themselves, and the environment that is beyond our control.

Dr Leaf’s quote doesn’t look quite so supportive after all.

References

Leaf, C.M., (2013) Switch On Your Brain : The Key to Peak Happiness, Thinking, and Health, Baker Books, Grand Rapids, Michigan

Lobo, I. & Shaw, K. (2008) Phenotypic range of gene expression: Environmental influence. Nature Education 1(1):12

Moalem, S., (2014) Inheritance: How our genes change our lives and our lives change our genes, Grand Central Publishing, New York.

Strachan, T. and Read, A., (2011) Human Molecular Genetics. 4th ed. Garland Science, New York.