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 and the Brain Changes Meme

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I swore on the Bible once.

One of my patients needed my testimony in a court case, and when I went to the lawyer’s offices to supply my statement, before they accepted it as official testimony, they asked me to swear on their Bible.  I’m not sure if the surprise I felt showed on my face.  I wasn’t expecting it, that’s for sure, since the only time I have seen people swear on the Bible was in cheesy American TV courtroom dramas.

It was a simple, but oddly surreal moment.  I placed my hand on the Bible and said, “I solemnly swear that I will tell the truth, the whole truth and nothing but the truth.”

We have heard it said so many times that we become blasé to the importance of those words.  But the truth is only true if it is, ”the whole truth and nothing but the truth”.

When Dr Leaf published her latest meme this morning, she was telling the truth.  She said via social media,

“Your brain changes as a result of your decisions.”

Dr Caroline Leaf is a Communication Pathologist and self-titled Cognitive Neuroscientist.  The on-going theme of her recent social media offerings is the “Mind over matter” meme: essentially our mind leads and our brain follows.  This was a fundamental argument in her most recent book too (see reference [1], pages 33 and 38).

The main problem for Dr Leaf is that real cognitive neuroscientists disagree, like Haggard,

“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]

But didn’t I say in the beginning of this blog that Dr Leaf was telling the truth?  Yes, I did say that.  And she is telling the truth … she’s just not telling the whole truth.

It’s true that our brains change as a result of our decisions.  But the brain changes as a result of hundreds of different inputs and signals.  Our brain is constantly changing – growing new branches and pruning others.  Most of these changes occur subconsciously.  Only the tiniest fraction would be due to our conscious decision-making.  The true limiting factor of our brains ability to change is genetics, specifically the genes that code for the proteins that are integral to the nerve cells ability to grow the branches it needs to make the right connections.

So while it’s not technically untrue, if you take Dr Leaf’s meme at face value, you would get the impression that the mind controls the brain, which was her intention.

In actual fact, our psychology is dependent on our biology, and the brain is in control of the mind, not the other way around.

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

Dr Caroline Leaf on James 1:21 – Redux

So, we’ve all heard the saying, “If at first you don’t succeed, try and try again.”  Dr Leaf has certainly done that.

Dr Caroline Leaf is a Communication Pathologist and self-titled Cognitive Neuroscientist.  Not content to completely misinterpret James 1:21 only once, she posted on social media today, “James 1:21.  Our thoughts and perceptions have a direct and overwhelmingly significant effect on the cells of our body.”

If for nothing else, Dr Leaf at least gets points for persistence.  A week and a half ago, Dr Leaf again used James 1:21 to attempt to justify a meme on perception.  I’d love to know what version of the Bible that she’s using, because it seems that in her Bible, James 1:21 can be interpreted any way that one wants.

Lets recap: 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, so I went through an on-line, widely used Greek lexicon, to look at the meanings of the words.  Then I translated 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.”

Wait … where did James talk about perception, and how our cells react to our thoughts?  Reviewing the scripture and its translation the second time around didn’t change anything, because there is nothing in James 1:21 that is in any way remotely connected to perception, thinking and our cells biological functioning.

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.

Which is why it is so important for Dr Leaf to interpret scripture correctly.  For the second time in two weeks, Dr Leaf has completely misapplied a scripture to one of her memes.  As if that isn’t concerning enough for a woman than regularly interprets scripture to audiences in the thousands every week, there isn’t any scientific evidence to back up her claim either.  As I have written about before, there is no evidence that the mind controls the brain.  Rather, our psychology is dependant on our biology.  More on this in future posts.  But the onus is on Dr Leaf to provide evidence to back up her claim.  I encourage her to publish specific evidence that she believes justifies her claims that our thoughts alter our cellular biology.

Otherwise, I think another popular phrase would better apply: “Quit while you’re ahead”.

UPDATE (17/6/2014)

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I was reviewing Dr Leaf’s posts tonight, and I came across this response that Dr Leaf posted on the 5th of June.  Clearly I wasn’t the only person who wondered exactly how James 1:21 applied to her meme.

Dr Leaf’s explained: “By ‘implanting the word of God your soul will be saved’ (James 1:21) – so by memorizing God’s Word we build healthy thoughts into our brain that improve the health of our cells.”

I’m sure that Dr Leaf thought she was climbing out of a hole, although I think she’s only dug herself deeper.

Firstly, while I’m not a trained theologian, I can read.  Dr Leaf reinterprets this long-suffering scripture again, “By ‘implanting the word of God your soul will be saved’.”  But that’s not what it says at all.  From the KJV which I originally quoted: ” … receive with meekness the engrafted word, which is able to save your souls.” (Emphasis added)  It’s a subtle but important difference.  My understanding is that salvation comes confession and repentance (Romans 10:9-10, 2 Corinthians 7:10).  The word of God is able to save souls, but as the Parable of the Sower (Luke 8:4-15) shows, it doesn’t always bear fruit.  Satan himself knows the Bible inside out, but he certainly isn’t saved.  Perhaps someone who is theologically trained can confirm the points here.  I’d certainly appreciate it.  But for now, I propose that Dr Leaf has misinterpreted this scripture again.

Dr Leaf goes on to claim that by memorizing scripture, “we build healthy thoughts in our brain that improve the health of our cells.”  Dr Leaf is really grasping at straws here.  The “soul” that James is referring to is psyche in the Greek, translated as “the seat of the feelings, desires, affections, aversions (our heart, soul etc.); the (human) soul in so far as it is constituted that by the right use of the aids offered it by God it can attain its highest end and secure eternal blessedness, the soul regarded as a moral being designed for everlasting life; the soul as an essence which differs from the body and is not dissolved by death (distinguished from other parts of the body)”. (http://www.blueletterbible.org/lang/lexicon/lexicon.cfm?Strongs=G5590&t=KJV)  So the word that James used has nothing to do with the body.

Dr Leaf has to apply her own set of assumptions to the scripture, that a saved soul must be healthy thoughts, and that healthy thoughts leads to healthy cells.  Its a myth that healthy thoughts lead to healthy cells (more on this in a future post).  To suggest that salvation and healthy thoughts are one and the same is also an assumption on Dr Leaf’s part, which I don’t think the scripture supports in any way.

So in short, Dr Leaf’s explanation really hasn’t helped her cause.  Her meme is still scripturally and scientifically baseless.

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 Myth of Mind Domination

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“You control your brain … your brain does not control you!”

So says Dr Caroline Leaf, Communication Pathologist and self-titled Cognitive Neuroscientist.

You’d hope that Dr Leaf would know. She says on her website that “Since the early 1980‘s she has studied and researched the Mind-Brain connection.” And if you take what she says at face value, it sure sounds right. Of course we’re in control. My brain does what I tell it to do. Except that it actually doesn’t. Our brain has a lot more control over us than we realize.

First of all, our “free” will isn’t actually free at all, but constrained by a number of unseen, subconscious processes that are entirely dependent on our brain. It may seem like we’re in complete control of our choices, but our subconscious brain has already done most of the work for us. Even if we had complete freedom over our choices, our “free” will would still require an intact brain in order to carry out its wishes.

The “control” of our brain is very similar to our “control” when we drive a car. When we say that we’re “controlling” the car, what we actually mean is that we are controlling the speed and direction of the car. But there are thousands of electrical and mechanical actions that take place each second that are vital for the running of the car, and that we have absolutely no direct control over. It just takes one loose nut or faulty fuse to make the car steer wildly out of control, or stop functioning entirely, and then we’re not in control at all.

In the same way, various diseases or lesions in the brain show that brain is really in control. The fact we don’t see all of the underlying processes in a fully functional brain simply provides the illusion of control.

For example, there are a number of lesions of the parietal lobes within the brain that give rise to some unusual but intriguing conditions. One of which is a condition called “Alien Hand Syndrome”. Wegner describes two patients with Alien Hand Syndrome, a lady whose “left hand would tenaciously grope for and grasp any nearby object, pick and pull at her clothes, and even grasp her throat during sleep … She slept with the arm tied to prevent nocturnal misbehavior”, and a man who, “While playing checkers on one occasion, the left hand made a move he did not wish to make, and he corrected the move with the right hand; however, the left hand, to the patient’s frustration, repeated the false move. On other occasions, he turned the pages of the book with one hand while the other tried to close it; he shaved with the right hand while the left one unzipped his jacket” [1]. Alien Hand Syndrome demonstrates that our decision-making and our action sequences are controlled by two separate systems in our brains.

There are other conditions that also show that our brains control us more than we control them. A more common example are the tic disorders, such as simple motor tics (sudden involuntary movements) and complex tic disorders, such as Tourette’s (best known for the involuntary tendencies to utter obscenities). Even more common are parasomnias – a group of disorders in which people perform complex behaviours during their sleep – sleep talking, sleep walking, sleep eating. One of my patients once drove her car while asleep (Honestly, that’s no exaggeration!).

So at best, we only have partial control of our brain. Our brain is driving, our mind just steers it a little, but it doesn’t take much for that veneer of control that we think we possess.

The other way in which we appear to have control over our brain is through free will. Free will has been debated for years on philosophical grounds, but over three decades ago, Libet performed an experiment that demonstrated measurable and predictable brain activity occurring up to a full second before a test subject was consciously aware of the intention to act [2]. More recently, a study by Soon et al showed that predictable brain activity occurred up to eight seconds before a person was aware of their intention to act [3]. As Bonn says, “the gist of these findings is that our feeling of having consciously willed an act is illusory in many ways. It seems that the conscious awareness of intention that we place so much weight upon, that we naively think of as causal, is, in fact, a narrative construction that is formed well after the train of causation has been set in motion.” [4]

The Oracle explained it to Neo, “… you didn’t come here to make the choice. You’ve already made it. You’re here to try to understand why you made it.” (Matrix Reloaded, 2003)

Haggard concludes, “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.” [5]

This does not eliminate our capacity to choose, but frames it in a more realistic fashion. As Bonn points out, “Although we are not consciously aware of what is going on at every stage of the chain of neural events leading to action, there is room for a degree of conscious involvement if only to pull the emergency brake before it is too late. Thus, although it may not be the initial source of motivations and behavioral impulses, the part of the mind that is self-reflective; that can envision the self in causal and narrative contexts, may serve important monitoring and control functions.” [4]

Again, we have less control over our brain than we realize. We feel like we have made a choice, but more often than not, our brain already made the choice for us up to eight seconds beforehand, and the feeling of intention that we have is simply our conscious mind catching up – not making the choice, but finding a reason for why we made the choice.

It’s always nice when people who call themselves neuroscientists tell us what feels intuitively correct. In the cold, hard light of day, actual neuroscientists don’t tell us what’s intuitively correct, but what’s actually correct. It may seem like our mind is in control of our brain, but modern neuroscience confirms that our brain is the dominant force, while our mind just helps to steer a little.

References

  1. Wegner, D.M., Precis of the illusion of conscious will. Behavioral and Brain Sciences, 2004. 27(5): 649-59
  2. 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
  3. 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
  4. 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
  5. Haggard, P., Human volition: towards a neuroscience of will. Nat Rev Neurosci, 2008. 9(12): 934-46 doi: 10.1038/nrn2497

 

The Discovery of Aspie

The Discovery of Aspie

Carol Gray and Tony Attwood

Some of this century’s best discoveries were creative and determined efforts to answer “What if…?” questions. What if people could fly? What if electrical energy could be harnessed to produce light? What if there was an easily accessible, international communication and information network? The answers have resulted in permanent changes: air travel, light bulbs, the Internet. These discoveries have rendered their less effective counterparts to relative extinction from use: gone is the stagecoach, gas lighting, and multi-volume hardbound encyclopedias. These improvements remind us of our option and ability to experiment, re-mold, re-think, and imagine. In that spirit, this article submits a new question: What if Asperger’s Syndrome was defined by its strengths? What changes might occur?

Moving from diagnosis to discovery
Making any diagnosis requires attention to weaknesses, the observation and interpretation of signs and symptoms that vary from typical development or health. Certainly it would be a little disarming to visit a doctor for a diagnosis, only to have her inquire, “So, what feels absolutely great?” The DSM 5 (American Psychiatric Association, 2013) assists in the identification of a variety of disorders. It is used by psychiatrists and psychologists to match observed weaknesses, symptoms and behaviors to text. In DSM 5 Autism Spectrum Disorder, which includes Asperger’s Syndrome, is identified by specific diagnostic criteria, a constellation of observed social and communication characteristics. Once diagnosed, a child or adult with the diagnosis is referred to with politically correct “people first” terminology, i.e. a person with Autistic Spectrum Disorder.

Unlike diagnosis, the term discovery often refers to the identification of a persons strengths or talents. Actors are discovered. Artists and musicians are discovered. A great friend is discovered. These people are identified by an informal combination of evaluation and awe that ultimately concludes that this person – more than most others – possesses admirable qualities, abilities, and/or talents. It’s an acknowledgment that, “… you know, he’s better than me at …”. In referring to people with respect to their talents or abilities, politically correct “people first” terminology is not required; labels like musician, artist, or poet are welcomed and considered complimentary.

If Asperger’s syndrome was identified by observation of strengths and talents, it would no longer be in the DSM 5, nor would it be referred to as a syndrome. After all, a reference to someones special strengths or talents does not use terms with negative connotations (it’s artist and poet, not Artistically Arrogant or Poetically Preoccupied), nor does it attach someones proper name to the word syndrome (it’s vocalist or soloist, not Sinatra’s Syndrome).

New ways of thinking of thinking often lead to discoveries that consequently discard their outdated predecessors. It could result in typical people rethinking their responses and rescuing a missed opportunity to take advantage of the contributions of those with autism to culture and knowledge.

Discovery Criteria for Aspergers Syndrome, by Attwood and Gray

A. A qualitative advantage in social interaction, as manifested by a majority of the following:

1. peer relationships characterised by an absolute loyalty and impeccable dependability
2. free of sexist, “age-ist”, or cultural biases; ability to regard others at “face value”
3. speaking one’s mind irrespective of social context or adherence to personal beliefs
4. ability to personal theory or perspective despite conflicting evidence
5. seeking an audience or friends capable of: enthusiasm for unique interests and topics; consideration of details; spending time discussing a topic that may not be of primary interest to others
6. listening without continual judgement or assumption
7. Interested primarily in significant contributions to conversation; preferring to avoid “ritualistic small talk” or socially trivial statements and superficial conversation
8. seeking sincere, positive, genuine friends with an unassuming sense of humour.

B. Fluent in autism, a social language characterised by at least three of the following:

1. a determination to seek the truth
2. conversation free of hidden meaning or agenda
3. advanced vocabulary and interest in words
4, fascination with word-based humour, such as puns
5. advanced use of pictorial metaphor

C. Cognitive skills characterised by at least four of the following:

1. strong preference for detail
2. original, often unique perspective in problem solving
3. exceptional memory and/or recall of details often forgotten or disregarded by others, for example: names, dates, schedules, routines
4. avid perseverance in gathering and cataloguing information on a topic of interest
5. persistence of thought
6. encyclopaedic or digital knowledge of one or more topics
7. knowledge of routines and a focused desire to maintain order, consistency and accuracy
8. clarity of values/decision making unaltered by political or financial factors

D. Additional possible features

1. acute sensitivity to specific sensory experiences and stimuli, for example: hearing, touch, vision, and/or smell
2. strength in individual sports and games, particularly those involving endurance, visual accuracy or intellect, including rowing, swimming, bowling or chess
3. “social unsung hero” with trusting optimism: frequent victim of social weakness and prejudices other others, while steadfast in the belief of the possibility of genuine friendship
4. increased probability over general population of attending university after high school
5. often take care of others outside the range of typical development

Perhaps we have discovered the next stage of human evolution?

(c) Tony Attwood and Carol Gray 2014 All Rights Reserved
Republished with permission from the author (TA)

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

Bad choices cause brain damage?

“To err is human; to forgive, divine.”  Alexander Pope.

I’m not perfect.  At least, not the last time I checked.  And we’re all the same, aren’t we.  We all know through experience that we all stuff things up on a fairly regular basis.  We make bad choices.  We’re human!

Dr Caroline Leaf, Communication Pathologist and self-titled Cognitive Neuroscientist, believes that these bad choices literally cause brain damage.  Her fundamental assumption is that our thoughts control our brain [1: p33].  These thoughts can be healthy or they can be toxic.  Toxic thoughts “are thoughts that trigger negative and anxious emotions, which produce biochemicals that cause the body stress.” [2: p19]

Dr Leaf’s assumption is that thoughts and bad choices cause our brain cells to shrivel or die. “Once your body is truly in stress mode and the cortisol is flowing, dendrites start shrinking and even ‘falling off’” [2: p32].  She also says that, “We have two choices, we can let our thoughts become toxic and poisonous or we can detox our negative thoughts which will improve our emotional wholeness and even recover our physical health.” [2: p21]

It sounds a little extreme.  We all make bad choices, and we all experience stress.  When we’re stressed, do our memories really go missing, or the dendrites of nerve cells shake and fall like tree branches in a storm?  If we make a bad choice, do we really get brain damage?  Lets see what the scientific literature has to say.

Imagine walking along a path in a forest and you see a snake, only inches in front of you on the path.  What do you do? When faced with a high level of acute stress, the brain switches into a binary mode – fight/flight or freeze. Self-preservation has to kick in.  The only decision you have to make then and there is whether to run, to try and kill the snake before it kills you, or stop dead still and hope that the snake ignores you and slithers away.

At that point, most memory is redundant, as is a high-level analysis of snake species, or any other cognitive pursuit.  The brain doesn’t need them at that precise moment.  If they did engage, they would just get in the way.  Switching the thinking parts of your brain off focuses your attention on the immediate danger.  It’s an adaptive survival response.  Meantime, your memories and your theoretical knowledge about snakes don’t disappear.  They are still there, unchanged.  It is false to suggest that the memories “shrink”.

We’ve all experienced “mental block”.  Sometimes when we get into a situation, like an exam or a business meeting, our stress levels are high, and binary mode kicks in again, although this time it can be a hindrance.  This phenomenon of mental block under high stress was first proposed in 1908 and is currently known as the Yerkes-Dodson Law, a fundamental principle of the behavioural sciences [3].  Similar to the stress-productivity curve, Yerkes and Dodson proposed a U-shaped curve to represent the relationship between arousal (which could be either level of consciousness or stress) and behavioural performance.  At low arousal, there is poor performance.  At the mid-point of arousal, there is peak performance, and at high arousal, performance diminishes.

But again, our memories don’t shrink, and our nerve cell branches don’t fall off.  Once we reduce our level of arousal, we move away from the fight/flight/freeze mode, and everything is still there (and we perform better, according to Yerkes-Dodson).

Dr Leaf has a favourite analogy of “neurons as trees”.  And if neurons are trees, then the branches can “fall off”.  But neurons are not trees and dendrites are not tree branches.  The dendrites do not ‘fall off’ the neuron.  The neurons in the brain have mechanisms for ongoing brain plasticity – the ability of the brain to adapt to the challenges and changes in its internal and external environment that are constantly occurring.  If the brain needs to build a new circuit to encode a new piece of information, then it grows new dendrites and creates new synapses.  But the brain is limited by the amount of energy it can consume, and therefore the number of synapses it can maintain.  So the brain trims unnecessary dendrites, a process called “synaptic pruning”.

Synaptic pruning is a normal process. Chechik and Meilijson confirm that, “Human and animal studies show that mammalian brains undergoes massive synaptic pruning during childhood, removing about half of the synapses until puberty.” [4]

Synaptic pruning is not deleterious, but beneficial.  Chechik and Meilijson also note that, “synaptic overgrowth followed by judicial pruning along development improves the performance of an associative memory network with limited synaptic resources.” [4] So synaptic pruning is a normal physiological process, and occurs in all of us for many reasons, predominantly to improve the efficiency of our neural networks.  Perhaps synaptic pruning associated with the stress response is also an adaptive process?

Synaptic pruning also occurs in other physiological states that have nothing to do with stress or thought, such as the effects of oestrogen during the menstrual cycle and at menopause [5, 6].

A link between stress and dendrite loss has been discovered, but it is not consistent.  Some authors like Kopp and Rethelyi suggest that “severe stress for a prolonged period causes damage in hippocampal pyramidal neurons, especially in the CA3 and CA4 region and reductions in the length and arborization of their dendrites.” [7] However, Chen et al writes, “Whereas hippocampus-mediated memory deficits commonly were associated with—and perhaps result from—loss of synapse-bearing dendrites and dendritic spines, this association has not been universal so that the structure–function relationship underlying the effects of stress on hippocampal neurons has not been resolved.” [8]

It’s more accurate to think that chronic stress causes dendritic remodeling in animals [9], in which some nerve cells prune their synapses, which others grow them, and energy is diverted away from new nerve cell formation to the new synapses that are needed to cope with the stress.

A number of scientists have pointed out that patients with depression or anxiety, who normally have high levels of stress, have a smaller hippocampus and larger amygdala, so stress and depression must cause the smaller brain regions [9].  There may be some reduction in the number of synapses within the hippocampus and the frontal lobes of the brain, which may account for the change in size observed by a number of researchers.  But the modern thinking on these changes is that they are associated with depression, not caused by depression [10] (Correlation does not equal causation).

So, stress is associated with depression, but this is because genetic defects in one or multiple genes reduce the ability for the brain cells to produce synaptic branches.  It’s this decrease in the number of synapses that contributes to the typical changes in the brain seen at autopsy of patients who suffered from depression or anxiety [11].  The reduced ability of the nerve cells to grow synapses means that new branches can’t grow fast enough to process the stress signals properly [11, 12].  The poor signal transmission leads to a predisposition towards mood disorders like anxiety and depression [10, 11, 13-15], and less synaptic branches means both a smaller volume of the hippocampus, and an inability to process stress signals leads to a larger, overactive amygdala.

In summary, synaptic pruning is not due to toxic thinking or bad choices, unless every one of us engages in nothing but toxic thinking from early childhood to puberty, and menopause causes bad choices and toxic thoughts.  Stress doesn’t cause dendrites to fall off, but causes a reorganization of the dendrites to adapt to the new signals. The reduced capacity to form new dendrites makes those prone to mood disorders more vulnerable to stress, and depression or anxiety is the end result.

We are all bound to make bad choices and to have stress.  They don’t cause brain damage.  Which if you’re not perfect like me, is good news.

References

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

2.         Leaf, C., Who Switched Off My Brain? Controlling toxic thoughts and emotions. 2nd ed. 2009, Inprov, Ltd, Southlake, TX, USA:

3.         Cohen, R.A., Yerkes–Dodson Law, in Encyclopedia of Clinical Neuropsychology, Kreutzer, J.S., et al., Editors. 2011, Springer Science+Business Media LLC: New York ; London. p. 2737-8.

4.         Chechik, G., et al., Neuronal regulation: A mechanism for synaptic pruning during brain maturation. Neural Comput, 1999. 11(8): 2061-80  http://www.ncbi.nlm.nih.gov/pubmed/10578044

5.         Chen, J.R., et al., Gonadal hormones modulate the dendritic spine densities of primary cortical pyramidal neurons in adult female rat. Cereb Cortex, 2009. 19(11): 2719-27 doi: 10.1093/cercor/bhp048

6.         Dumitriu, D., et al., Estrogen and the aging brain: an elixir for the weary cortical network. Ann N Y Acad Sci, 2010. 1204: 104-12 doi: 10.1111/j.1749-6632.2010.05529.x

7.         Kopp, M.S. and Rethelyi, J., Where psychology meets physiology: chronic stress and premature mortality–the Central-Eastern European health paradox. Brain Res Bull, 2004. 62(5): 351-67 doi: 10.1016/j.brainresbull.2003.12.001

8.         Chen, Y., et al., Correlated memory defects and hippocampal dendritic spine loss after acute stress involve corticotropin-releasing hormone signaling. Proc Natl Acad Sci U S A, 2010. 107(29): 13123-8 doi: 10.1073/pnas.1003825107

9.         Karatsoreos, I.N. and McEwen, B.S., Psychobiological allostasis: resistance, resilience and vulnerability. Trends Cogn Sci, 2011. 15(12): 576-84 doi: 10.1016/j.tics.2011.10.005

10.       Palazidou, E., The neurobiology of depression. Br Med Bull, 2012. 101: 127-45 doi: 10.1093/bmb/lds004

11.       Karatsoreos, I.N. and McEwen, B.S., Resilience and vulnerability: a neurobiological perspective. F1000Prime Rep, 2013. 5: 13 doi: 10.12703/P5-13

12.       Russo, S.J., et al., Neurobiology of resilience. Nature neuroscience, 2012. 15(11): 1475-84

13.       Felten, A., et al., Genetically determined dopamine availability predicts disposition for depression. Brain Behav, 2011. 1(2): 109-18 doi: 10.1002/brb3.20

14.       Bradley, R.G., et al., Influence of child abuse on adult depression: moderation by the corticotropin-releasing hormone receptor gene. Arch Gen Psychiatry, 2008. 65(2): 190-200 doi: 10.1001/archgenpsychiatry.2007.26

15.       Hauger, R.L., et al., Role of CRF receptor signaling in stress vulnerability, anxiety, and depression. Ann N Y Acad Sci, 2009. 1179: 120-43 doi: 10.1111/j.1749-6632.2009.05011.x