Dr Caroline Leaf and the Mixed Message Memes

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If you were talking to your doctor, and she said, “Smoking is bad for you”, while lighting a cigarette for herself, would you be confused? Bit of a mixed message, don’t you think?

When I got back to Facebook last night, I found this interesting post from Dr Leaf: “If you have just spoken or done something … It means you have the physical root thought in your brain.” Perhaps not interesting in an I-never-knew-that sort of way … more interesting in a yet-another-mixed-message sort of way.

Dr Caroline Leaf is a Communication Pathologist and a self-titled Cognitive Neuroscientist. She has a habit of posting fluffy pseudoscientific memes to her social media feeds, which sound plausible at face value, but look a little closer, and they crumble like a sand castle at high tide.

Her current post is actually a bit sturdier than usual. We do use information we’ve learned to guide our ultimate behaviour, which include our words and our actions. But that’s not the whole story.

Our brain is an amazing organ. It processes a torrent of incoming information, compares it to previous experience stored in memory, and then delivers real-time instructions to the rest of the body, whilst updating the memory systems with the new information received. However, the brain also has a limited amount of energy that it can utilise – the brain only runs on about 40 watts of power [1: p7] (the same as a low power light bulb). In order to use this limited energy efficiently, the brain automates certain actions, like skills or habits, while retaining the flexibility to handle situations or to perform different actions than the skills or habits that we have developed.

The brain achieves this feat of brilliance by having a number of different types of memory [2] – procedural memory, priming, classical conditioning and non-associative learning make up implicit memory (memory not available to conscious awareness). Declarative memory is the fifth type of memory, which has two sub-components: episodic memory, which is the recallable memory of specific events (that you had coffee and eggs for breakfast), which itself is heavily dependent on semantic memory, the recallable memory for concepts (the abstract concepts of coffee, eggs, and breakfast) [3].

The storage of memories within declarative memory is also done piecemeal, by breaking down the information stored into chunks. Byrne notes, “We like to think that memory is similar to taking a photograph and placing that photograph into a filing cabinet drawer to be withdrawn later (recalled) as the ‘memory’ exactly the way it was placed there originally (stored). But memory is more like taking a picture and tearing it up into small pieces and putting the pieces in different drawers. The memory is then recalled by reconstructing the memory from the individual fragments of the memory.” [4] Retrieving the original memory is an inaccurate process, because sometimes pieces of the memory are lost, faded or mixed up with another [5]. What the memory systems lose in accuracy of recall is more than made up for by the flexibility of the information stored in memory to plan current action, and to imagine possible future scenarios.

Each time the brain decides on an action, it subconsciously performs five different steps to determine the best action to take, although the best way to consider the process is simply to say that “voluntary” action is a flexible and intelligent interaction with the subject’s current and historical context (present situation and past experience) [6].

In a new situation, the brain takes the information from the senses (sight, hearing etc) and compares it with the necessary pieces of information recalled from memory, including previous actions taken in similar situations and their outcome. It then decides on the best course of action, plans what to move, when to move, how to move, and then performs one more final check before proceeding. If the situation is familiar, and the brain has a previous script to follow, like a skill or a habit, it will perform those actions preferentially because it’s more efficient in terms of brain energy used, but if there is no previous script, the brain will plan a novel set of actions appropriate to the situation.

The best example of this is driving a car. I learnt to drive in my parents’ 1970-something, 4-to-the-floor Chrysler Galant. The skills required to handle a manual transmission car with an old clutch was challenging to learn, but once those skills were mastered and road rules learnt, I could drive successfully. But I didn’t need to learn evasive maneuvers. When confronted with an emergency situation for the first time, my brain moved my body very quickly to control the car in ways I’d not practiced, before my conscious mind had a chance to process the incident. So my brain used skills I had learnt in ways that I had not learnt, independent of my conscious will.

Dr Leaf’s underlying assumption is that we are in full control of our thoughts and actions. Unfortunately for Dr Leaf, neuroscience proves that predictable brain activity occurs several seconds before a person is aware of their intention to act [7, 8], which runs counter to her presupposition. To try and patch the enormous hole in her argument, she contends that the brain activity that occurs before we are consciously aware of our intentions is just our non-conscious brain accessing our stored, previously conscious thoughts (see also [9], page 42). The implication is that anything you do is still a choice that you made in either the present, or your past. As she said in the Facebook post, “Everything you say and do is first a thought that you have built in your brain.”

Unfortunately for Dr Leaf, cognitive neuroscience disproves her folk-science. It’s way oversimplified to suggest that everything we do is based on our thought life. There are many chunks of our memory that don’t come from a willful, conscious input of information (acquired fear is one example). And the brain can use chunks of memory, often from memory systems not accessible by our conscious awareness, to produce complex actions that are completely new, without needing our conscious input.

Even though cognitive neuroscience disproves her meme, which is embarrassing enough for a woman who calls herself a cognitive neuroscientist, the bigger problem for this meme is that Dr Leaf is again contradicting herself.

About a month ago, Dr Leaf published on her social media feeds, “Don’t blame your physical brain for your decisions and actions. You control your brain!” Now she says that your words and actions are the result of a hardwired “physical root thought”, so your decisions and actions ARE the result of your physical brain. Which is it Dr Leaf? For the sake of her followers, her clarification would be welcome. After all, the more she contradicts herself, the more doubt she casts over the validity of the rest of her writing and teaching. Is she accurately interpreting research, and drawing valid conclusions? Dr Leaf is welcome to comment.

But one thing’s for sure; her mixed message memes are certainly not doing her any favours.

References

  1. Berns, G., Iconoclast : a neuroscientist reveals how to think differently. 2008, Harvard Business School Press, Boston:
  2. Squire, L.R. and Zola, S.M., Structure and function of declarative and nondeclarative memory systems. Proceedings of the National Academy of Sciences, 1996. 93(24): 13515-22 http://www.pnas.org/content/93/24/13515.abstract
  3. Binder, J.R. and Desai, R.H., The neurobiology of semantic memory. Trends Cogn Sci, 2011. 15(11): 527-36 doi: 10.1016/j.tics.2011.10.001
  4. Byrne, J.H. Learning and Memory (Section 4, Chapter 7). Neuroscience Online – an electronic textbook for the neurosciences 2013 [cited 2014, Jan 3]; Available from: http://neuroscience.uth.tmc.edu/s4/chapter07.html.
  5. Bonn, G.B., Re-conceptualizing free will for the 21st century: acting independently with a limited role for consciousness. Front Psychol, 2013. 4: 920 doi: 10.3389/fpsyg.2013.00920
  6. Haggard, P., Human volition: towards a neuroscience of will. Nat Rev Neurosci, 2008. 9(12): 934-46 doi: 10.1038/nrn2497
  7. Libet, B., et al., Time of conscious intention to act in relation to onset of cerebral activity (readiness-potential). The unconscious initiation of a freely voluntary act. Brain, 1983. 106 (Pt 3): 623-42 http://www.ncbi.nlm.nih.gov/pubmed/6640273
  8. Soon, C.S., et al., Unconscious determinants of free decisions in the human brain. Nat Neurosci, 2008. 11(5): 543-5 doi: 10.1038/nn.2112
  9. Leaf, C.M., Switch On Your Brain : The Key to Peak Happiness, Thinking, and Health. 2013, Baker Books, Grand Rapids, Michigan:

(PS: And happy Independence Day, USA! #4thofjuly )

Dr Caroline Leaf and the Myth of the Blameless Brain

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When I came back to Facebook this morning, I found this from Dr Leaf on my feed,

“Don’t blame your physical brain for your decisions and actions. You control your brain!”

Dr Caroline Leaf is a Communication Pathologist and a self-titled Cognitive Neuroscientist. Her post follows her theme of the last couple of weeks, the premise that the mind is the dominant cognitive force, controlling the physical brain, and indeed, all matter. I have written about the Myth of Mind Domination in a previous blog. But Dr Leaf’s latest offering here deserves special attention.

Lets think about her statement in more detail:

“Don’t blame your physical brain for your decisions and actions.”

What Dr Leaf is really saying is that the physical brain has no role in your choices or behaviour whatsoever, because if your physical brain had a role in the decisions and actions you make, it would also carry some blame for your poor decisions and actions.

“You control your brain.”

The question to ask here is, “Which part of ‘you’ controls your brain?” Her answer would be, “Your mind”, although she never says where the mind is. Certainly not in the physical brain or even in our physical body, since “Our mind is designed to control the body, of which the brain is a part, not the other way around.” [1: p33].

So an ethereal, disembodied force is in full control of our physical body, such that our brain has no role in the decisions we make or actions we take. Even at this stage of analysis, Dr Leaf’s statement is ludicrous. But wait, there’s more.

Dr Leaf’s statement puts her at odds with real Cognitive Neuroscientists. Professor Patrick Haggard is the Deputy Director of the Institute of Cognitive Neuroscience at the University College London. He has authored or co-authored over 350 peer-reviewed articles on the neuroscience of making choices. He writes, “Modern neuroscience rejects the traditional dualist view of volition as a causal chain from the conscious mind or ‘soul’ to the brain and body. Rather, volition involves brain networks making a series of complex, open decisions between alternative actions.” [2] Strike one for Dr Leaf.

Dr Leaf’s statement puts her at odds with herself. Two weeks ago when misinterpreting James 1:21, Dr Leaf wrote, “How you react to events and circumstances of your life is based upon your perceptions.” Perception is classically defined in neurobiology as conscious sensory experience [3: p8] although the work of cognitive neuroscientists has shown that perception can also be non-conscious [4, 5]. Either way, perception is based entirely on processing within the brain [3: p6-11]. So one week, Dr Leaf is saying that our brain determines how we behave, and then ten days later, she is telling us that our brain does not determine how we behave. Which is it? Strike two for Dr Leaf.

Finally, Dr Leaf’s statement is borderline insulting to the sufferers of congenital or acquired brain disorders. Would you tell a stroke patient that they shouldn’t blame their physical brain for their immobility, because they’re mind is in control of their brain? What about a child with Cerebral Palsy? Would you tell a mother of a child with Downs Syndrome that their child is having recurrent seizures because they aren’t using their mind properly to control their brain? Dr Leaf is doing exactly that. I find it incredible that she could be so insensitive, given her background as a speech pathologist working with patients with Acquired Brain Injury.

I imagine that her defence would be something along the lines of, “What I meant was, ‘don’t blame your normal physical brain for your decisions and actions. You control your functional brain.’” That sort of explanation would be less insulting to people with strokes or brain injuries, but it then undermines her whole premise. The hierarchy of the brain and the mind doesn’t change just because a part of the brain is damaged.

Besides, changes to brain function at any level can change the way a person thinks and behaves. The classic example was Phineas Gage, who in 1848, accidentally blasted an iron rod through his skull, damaging his left frontal lobe. History records that Gage’s well-mannered, pleasant demeanour changed suddenly into a fitful, irreverent, obstinate and capricious man whose workmates could no longer stand him [6]. Medical science has documented numerous cases of damage to the right ventromedial prefrontal cortex causing acquired sociopathy [7]. How can the mind be in control of the brain when an injury to the brain causes a sudden change in thought pattern and behaviour? Clearly one CAN blame the physical brain for one’s decisions and actions. Strike three. You’re out.

Dr Leaf is welcome to comment here. Perhaps she meant something completely different by her post, although there’s only so many ways that such a statement can be interpreted.

Ultimately, Dr Leaf’s love of posting pithy memes of dubious quality is now getting embarrassing. Being so far behind the knowledge of a subject in which she claims expertise is ignominious. Undermining her own premise and contradicting herself is just plain embarrassing. But to be so insensitive to some of the most vulnerable is poor form. I think she’d be well served by re-examining her facts and adjusting her teaching.

References

  1. Leaf, C.M., Switch On Your Brain : The Key to Peak Happiness, Thinking, and Health. 2013, Baker Books, Grand Rapids, Michigan:
  2. Haggard, P., Human volition: towards a neuroscience of will. Nat Rev Neurosci, 2008. 9(12): 934-46 doi: 10.1038/nrn2497
  3. Goldstein, E.B., Sensation and perception. 8th ed. 2010, Wadsworth, Cengage Learning, Belmont, CA:
  4. Kouider, S. and Dehaene, S., Levels of processing during non-conscious perception: a critical review of visual masking. Philos Trans R Soc Lond B Biol Sci, 2007. 362(1481): 857-75 doi: 10.1098/rstb.2007.2093
  5. Tamietto, M. and de Gelder, B., Neural bases of the non-conscious perception of emotional signals. Nat Rev Neurosci, 2010. 11(10): 697-709 doi: 10.1038/nrn2889
  6. Fumagalli, M. and Priori, A., Functional and clinical neuroanatomy of morality. Brain, 2012. 135(Pt 7): 2006-21 doi: 10.1093/brain/awr334
  7. Mendez, M.F., The neurobiology of moral behavior: review and neuropsychiatric implications. CNS Spectr, 2009. 14(11): 608-20 http://www.ncbi.nlm.nih.gov/pubmed/20173686

 

Dr Caroline Leaf on James 1:21

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What causes you to react to things the way you do? According to Dr Leaf, we react to things because of our perceptions, because James 1:21 says so.

Dr Caroline Leaf is a Communication Pathologist and self-titled Cognitive Neuroscientist. She posted on social media today that,

“James 1:21. How you react to events and circumstances of your life is based upon your perceptions.”

Just like her other social media memes, we’re supposed to smile and nod, and accept that it must be right on face value alone. Remember, “Trust me, I’m a cognitive neuroscientist”.

Ironically, Dr Leaf is on the right track with her meme. Perception is very important to how our brains process incoming information, although it is only one small part in a much larger picture. But that is for a future post.

What made me scratch my head about her post was the scripture reference that she tags onto the meme, as if it gives her factoid some automatic level of credibility. I never knew that James made any reference to reacting to life circumstances, so I looked up the scripture.

James 1:21 says, “Wherefore lay apart all filthiness and superfluity of naughtiness, and receive with meekness the engrafted word, which is able to save your souls.” (KJV)

There are too many big words there for my liking. But I also thought it would be a useful exercise to look at the meanings of the words to translate them into something more understandable, to make sure that I didn’t miss the bit about perception.

Using the Strong’s dictionary and concordance built in to the Blue Letter Bible site (http://www.blueletterbible.org/Bible.cfm?b=Jas&c=1&v=21&t=KJV#s=1147021) I was able to translate the original Greek into something more manageable.

“Therefore shed all the morally defiling wickedness and excess malice, and, with meekness, embrace the teaching that is implanted by your mentors, which has the power to rescue your eternal soul.”

Hmmm … perhaps I mistranslated, but I missed the part where James talked about perception, and how we react to circumstances.

Or more likely, it wasn’t in this scripture at all.

Scripture is the inspired word of God, and “is useful for teaching, rebuking, correcting and training in righteousness, so that the servant of God may be thoroughly equipped for every good work.” (2 Tim 3:16-17, NIV) What James is writing about is essential, and Christians need to embrace what he was teaching.

Unfortunately for Dr Leaf, her imprecise application of scripture doesn’t help anyone. It confuses her readers who look more deeply into either the scripture or the science, and are lost as to why they don’t meet up. Or it damages her reputation as a scientist or a teacher, since it isn’t clear exactly what she is trying to say or how she arrived at her conclusions.

I have not doubt that if Dr Leaf has something to share on social media many people that would like to hear it. But it has to be referenced properly if it is going to carry any weight.

Dr Caroline Leaf and the Sound Mind Meme

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Caroline Leaf is a brave woman.

Dr Caroline Leaf is a Communication Pathologist and self-titled Cognitive Neuroscientist.  She regularly publishes memes on her social media sites like FaceBook and Instagram that are supposed to reinforce her main teaching.

Her recent post declared:

“Your mind is all-powerful.  Your brain simply captures what your mind dictates. 2 Timothy 1:7”

We’re supposed to smile and nod, and accept that it must be right on face value alone.  Like, “Trust me, I’m a cognitive neuroscientist”.

But if we peel away the thin veneer of trust that covers the surface of this meme, we see that there isn’t much in the way of substance that supports it.

For a start, the only reference that Dr Leaf supplies is the scripture from 2 Timothy 1:7. She’s used this scripture in her work before, stating in her 2013 book, “For now, rest in the assurance that what God has empowered you to do with your mind is more powerful and effective than any medication, any threat, any sickness, or any neurological challenge.  The scripture is clear on this: You do not have a spirit of fear but of love, power and a sound mind (2 Tim 1:7).” [1]

So, first things first: the scripture 2 Timothy 1:7 says: “For God hath not given us the spirit of fear; but of power, and of love, and of a sound mind.”  (KJV)  But what does it actually mean?

Studying the full context and the original Greek reveals that this verse is not a reference to our mental health, but to the courage to perform the work that God has given us.

The Greek word for “fear” in this scripture refers to “timidity, fearfulness, cowardice”, not to anxiety or terror.  The Greek word that was translated “of a sound mind” refers to “self-control, moderation”, not to serenity.  So Paul is telling Timothy that God doesn’t make him timid, but full of power, love and self-control.  Paul teaches that through the Holy Spirit, we have all the tools: power, love and the control to use them, so we don’t have to be afraid.

In addition, looking at the verse in its context, and in a different translation, shows it in a completely different light to the way Dr Leaf promotes it.  From the NIV, “I am reminded of your sincere faith, which first lived in your grandmother Lois and in your mother Eunice and, I am persuaded, now lives in you also.  For this reason I remind you to fan into flame the gift of God, which is in you through the laying on of my hands. For the Spirit God gave us does not make us timid, but gives us power, love and self-discipline. So do not be ashamed of the testimony about our Lord or of me his prisoner. Rather, join with me in suffering for the gospel, by the power of God.” (2 Timothy 1:5-8)

The scripture doesn’t say that our minds are more powerful than medication, sickness or “neurological challenge”.  It clearly doesn’t say that our mind is all-powerful, and that our brains simply capture what our minds dictate.  This scripture doesn’t have anything to do with our mental health (nor is there any scientific evidence to suggest that our mind is all-powerful or that the brain captures what our mind dictates, although that is another blog entirely (see also: Dr Caroline Leaf and the Myth of Mind Domination)).

Scripture is the inspired word of God.  It’s poor form to knowingly misquote someone to support your position, but it’s a very brave person that would misquote scripture for the sake of their argument.  And the inaccuracy of Dr Leaf’s use of both scripture and science surely calls into question the accuracy of all of her other memes.  Perhaps those who follow Dr Leaf’s social media feeds should also start taking them with more than a pinch of salt.

References

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

(New Testament Greek lexicon used for the word search was the Blue Letter Bible Strongs Lexicon, Reference: Greek Lexicon: G1167 (KJV). Retrieved from http://www.blueletterbible.org/lang/lexicon/lexicon.cfm?Strongs=G1167&t=KJV and Greek Lexicon: G4995 (KJV). Retrieved from http://www.blueletterbible.org/lang/lexicon/lexicon.cfm?Strongs=G4995&t=KJV)

Dr Caroline Leaf and the 98 Percent Myth

Dr Caroline Leaf believes that nearly all our diseases come from our thoughts.

Dr Caroline Leaf believes that nearly all our diseases come from our thoughts.

In the hustle and bustle of daily life, most people wouldn’t stop to consider what makes people sick.  In my profession, I get a front row seat.

In the average week, I get to see a number of different things.  Mostly “coughs, colds and sore holes” as the saying goes, although there are some rarer things too.  And sometimes, people present with problems that aren’t for the faint of heart (or stomach – beware of nail guns is all I can say).

Normally, the statistics of who comes in with what doesn’t make it beyond the desk of the academic or health bureaucrat.  The numbers aren’t as important as the people they represent.

But to Dr Caroline Leaf, Communication Pathologist and self-titled Cognitive Neuroscientist, the numbers are all important.  To support her theory of toxic thoughts, Dr Leaf has stated that “75 to 98% of mental and physical (and behavioural) illness comes from one’s thought life” [1: p37-38].  She has repeated that statement on her website, on Facebook, and at seminars.

As someone with a front row seat to the illnesses people have, I found such a statement perplexing.  In the average week, I don’t see anywhere near that number.  In general practices around Australia, the number of presentations for psychological illnesses is only about eight percent [2].

But Australian general practice is a small portion of medicine compared to the world’s total health burden.  Perhaps the global picture might be different?  The World Health Organization, the global authority on global health, published statistics in November 2013 on the global DALY statistics [3] (a DALY is a Disability Adjusted Life Year).  According to the WHO, all Mental and Behavioural Disorders accounted for only 7.2% of the global disease burden.

You don’t need a statistics degree to know that seven percent is a long way from seventy-five percent (and even further from 98%).

Perhaps a large portion of the other ninety-three percent of disease that was classified as physical disease was really caused by toxic thoughts?  Is that possible?  In short: No.

When considered in the global and historical context, the vast majority of illness is related to preventable diseases that are so rare in the modern western world because of generations of high quality public health and medical care.

In a recent peer-reviewed publication, Mara et al state, “At any given time close to half of the urban populations of Africa, Asia, and Latin America have a disease associated with poor sanitation, hygiene, and water.” [4] Bartram and Cairncross write that “While rarely discussed alongside the ‘big three’ attention-seekers of the international public health community—HIV/AIDS, tuberculosis, and malaria—one disease alone kills more young children each year than all three combined. It is diarrhoea, and the key to its control is hygiene, sanitation, and water.” [5] Hunter et al state that, “diarrhoeal disease is the second most common contributor to the disease burden in developing countries (as measured by disability-adjusted life years (DALYs)), and poor-quality drinking water is an important risk factor for diarrhoea.” [6]

Diarrhoeal disease in the developing world – the second most common contributor to disease in these countries, afflicting half of their population – has nothing to do with thought.  It’s related to the provision of toilets and clean running water.

We live in a society that prevents half of our illnesses because of internal plumbing.  Thoughts seem to significantly contribute to disease because most of our potential illness is prevented by our clean water and sewerage systems.  Remove those factors and thought would no longer appear to be so significant.

In the same manner, modern medicine has become so good at preventing diseases that thought may seem to be a major contributor, when in actual fact, most of the work in keeping us all alive has nothing to do with our own thought processes.  Like sanitation and clean water, the population wide practices of vaccination, and health screening such as pap smears, have also significantly reduced the impact of preventable disease.

Around the world, “Recent estimates of the global incidence of disease suggest that communicable diseases account for approximately 19% of global deaths” and that “2.5 million deaths of children annually (are) from vaccine-preventable diseases.” [7] Again, that’s a lot of deaths that are not related to thought life.

Since 1932, vaccinations in Australia have reduced the death rate from vaccine-preventable diseases by 99% [8].  Epidemiological evidence shows that when vaccine rates increase, sickness from communicable diseases decrease [9: Fig 2, p52 & Fig 8, p67].

Population based screening has also lead to a reduction in disease and death, especially in the case of population screening by pap smears for cervical cancer.  Canadian public health has some of the best historical figures on pap smear screening and cervical cancer. In Canada, as the population rate of pap smear screening increased, the death rate of women from cervical cancer decreased.  Overall, pap smear screening decreased the death rate from cervical cancer by 83%, from a peak of 13.5/100,000 in 1952 to only 2.2/100,000 in 2006, despite an increase in the population and at-risk behaviours for HPV infection (the major risk factor for cervical cancer) [10].

And around the world, the other major cause of preventable death is death in childbirth.  The risk of a woman dying in childbirth is a staggering one in six for countries like Afghanistan [11] which is the same as your odds playing Russian Roulette.  That’s compared to a maternal death rate of one in 30,000 in countries like Sweden.  The marked disparity is not related to the thought life of Afghani women in labour.  Countries that have a low maternal death rate all have professional midwifery care at birth.  Further improvements occur because of better access to hospital care, use of antibiotics, better surgical techniques, and universal access to the health system [11].  Again, unless one’s thought life directly changes the odds of a midwife appearing to help you deliver your baby, toxic thoughts are irrelevant as a cause of illness and death.

Unfortunately for Dr Leaf, her statement that “75 to 98 percent of mental, physical and behavioural illnesses come from toxic thoughts” is a myth, a gross exaggeration of the association of stress and illness.

In the global and historical context of human health, the majority of illness is caused by infectious disease, driven by a lack of infrastructure, public health programs and nursing and medical care.  To us in the wealthy, resource-rich western world, it may seem that our thought life has a significant effect on our health.  That’s only because we have midwives, hospitals, public health programs and internal plumbing, which stop the majority of death and disease before they have a chance to start.

Don’t worry about toxic thoughts.  Just be grateful for midwives and toilets.

References

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

2.         FMRC. Public BEACH data. 2010  [cited 16JUL13]; Available from: <http://sydney.edu.au/medicine/fmrc/beach/data-reports/public%3E.

3.         World Health Organization, GLOBAL HEALTH ESTIMATES SUMMARY TABLES: DALYs by cause, age and sex, GHE_DALY_Global_2000_2011.xls, Editor 2013, World Health Organization,: Geneva, Switzerland.

4.         Mara, D., et al., Sanitation and health. PLoS Med, 2010. 7(11): e1000363 doi: 10.1371/journal.pmed.1000363

5.         Bartram, J. and Cairncross, S., Hygiene, sanitation, and water: forgotten foundations of health. PLoS Med, 2010. 7(11): e1000367 doi: 10.1371/journal.pmed.1000367

6.         Hunter, P.R., et al., Water supply and health. PLoS Med, 2010. 7(11): e1000361 doi: 10.1371/journal.pmed.1000361

7.         De Cock, K.M., et al., The new global health. Emerg Infect Dis, 2013. 19(8): 1192-7 doi: 10.3201/eid1908.130121

8.         Burgess, M., Immunisation: A public health success. NSW Public Health Bulletin, 2003. 14(1-2): 1-5

9.         Immunise Australia, Myths and Realities. Responding to arguments against vaccination, A guide for providers. 5th ed. 2013, Commonwealth of Australia, Department of Health and Ageing, Canberra:

10.       Dickinson, J.A., et al., Reduced cervical cancer incidence and mortality in Canada: national data from 1932 to 2006. BMC Public Health, 2012. 12: 992 doi: 10.1186/1471-2458-12-992

11.       Ronsmans, C., et al., Maternal mortality: who, when, where, and why. Lancet, 2006. 368(9542): 1189-200 doi: 10.1016/S0140-6736(06)69380-X