Running of the Elephants – Why thought suppression doesn’t work

Have you ever found yourself about to give a speech or sit an exam, and one of your friends tries to calm you down by saying, “Stop worrying … just don’t think about it!”  Does that ever work?  Not usually!  The more you try to intentionally block it from your mind, the more it wants to pop up again.

Why is that?  It seems intuitive that if you don’t want to think about something, all you need to do is to take control and block it out of your mind, right?

One of Hollywood’s better movies in recent times was “Inception”.  In one of the key early scenes, Arthur is explaining to Saito why inception is impossible,

Saito: If you can steal an idea, why can’t you plant one there instead?
Arthur: Okay, this is me, planting an idea in your mind. I say: don’t think about elephants. What are you thinking about?
Saito: Elephants?”

This is a great little dialogue about thought suppression.  Thought suppression is the process of consciously trying to avoid certain thoughts, either by trying to replace the unwanted thought with another thought, or simply trying to repress the unwanted thought.

Our minds tend to focus on the content of a subject.  If the subject is elephants, no matter what words I put in front of it, your mind will think about elephants.  Like if I say, “I love elephants, or I say “Don’t think about elephants”, your brain hears, “blah blah blah elephants.”  And having been sensitized to the idea of not thinking about elephants, when your mind inevitably brings it up again, you’re primed to pay even more attention to it, “D’oh, I’ve just thought about elephants again … stop thinking about elephants …”.

This phenomenon is even more pronounced if your mind has already been focusing on the subject.  If you’re mind is going over and over a speech you have to give and I say, “Oh, don’t worry about that speech”, all your mind registers is, “blah blah blah SPEECH”.

Although it’s been discussed in the psychological sciences for decades, it’s only been since the late 1980’s that considerable attention has been given to the concept of thought suppression.  Despite our natural tendencies to try it or recommend it to people, the conclusion of nearly all the research is the same: thought suppression doesn’t work.

Wenzlaff and Wegner, two American psychology researchers, looked at all of the different research on thought suppression and came to the following conclusion,

“What has compelled the interest of the scientific and clinical communities is that suppression is not simply an ineffective tactic of mental control; it is counterproductive, helping assure the very state of mind one had hoped to avoid. The problem of thought suppression is aggravated by its intuitive appeal and apparent simplicity, which help mask its false promises.” [1]

I’m not really sure why we naturally gravitate to thought suppression.  Perhaps it’s part of our natural delusion of control.  Perhaps it’s a throwback from the pop-psychology assumptions that we can control our destiny, or the common myth that our mind is in control of our brain.

Whatever the reason, as time has passed, researchers are coming to understand why thought suppression is so unhelpful.  This quote from Magee and his colleagues helps to explain why:

“This shift in focus parallels advances in cognitive theories of intrusive thoughts, which suggest that having intrusive thoughts is a normative phenomenon; instead, the way an individual interprets those thoughts is expected to lead to benign versus serious outcomes … Similarly, having difficulties with thought suppression is a common experience … it is the way an individual interprets that experience that may be key. Previous discussions of thought suppression have frequently implied that people having difficulties with thought suppression often ascribe negative meaning to their difficulties.” [2]

We naturally struggle to suppress intrusive thoughts because intrusive thoughts are normal.  Trying to suppress them is like trying to suppress any other normal biological process.  Try to stop breathing for any length of time and you’ll see what I mean – it’s impossible, and trying is simply counterproductive.

The key is how we react to or feel about our thoughts.  If we feel like our thoughts might be somehow causing us harm, then our failure to stop them from bubbling up to the surface of our consciousness is going to cause us distress.  It’s a double whammy – we’re stressed because we’re expecting the negative consequences of our thoughts, and we’re distressed by our ‘failure’ to stop them.

Since it first started more than a century ago, the death toll from the famous Pamplona event, “Running of the Bulls” currently stands at 13.  Countless others have been gored and trampled.  Who are the people who get injured during the event?  Certainly not the smart ones standing behind the barriers on the edge of the streets, or the ones watching it broadcast on TV?  Only the morons who try to outrun the pack of foot-long bony skewers attached to the half-ton lumps of very cranky steak.

Similarly, the best way to manage our thoughts is to learn not to fight with them in the first place.  By non-judgmentally observing them, we can simply observe our thoughts for what they are … just thoughts.  By stepping back from our thoughts and giving them room, we find that they don’t have any real power over us.  Stepping back away from our thoughts and letting them be is the skill of defusion, one part of the process of psychological acceptance.  It’s the first step in living a life abundant in meaning and significance.

So just remember: don’t try to suppress an unwelcome thought.  Having intrusive thoughts is actually a normal process, not a sign of disease or mental weakness.  They’re not toxic or harmful, they’re just thoughts.  Give them space, like you would a charging angry bull (or elephant!)

References

[1]        Wenzlaff RM, Wegner DM. Thought suppression. Annual review of psychology 2000;51(1):59-91.
[2]        Magee JC, Harden KP, Teachman BA. Psychopathology and thought suppression: a quantitative review. Clinical psychology review 2012 Apr;32(3):189-201.

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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

Dr Caroline Leaf – Serious questions, few answers (Part 1)

Caroline Leaf. The name is popping up more and more around Christian circles. I was curious to hear her speak, since as a Christian and a (family) physician, I like to know how people integrate science and spirituality. So I took the opportunity to drive down to Kings Christian Church on the Gold Coast to hear what she had to say.

I left with more questions than answers.  And some serious concerns.

The following blog posts are a discussion on some of the points that she raised. I simply don’t have the time to go through all of them, although I’m seriously considering whether to do a formal review and response to her teaching.

I had to divide up the original post into three parts to make it more manageable. Here’s part 1, in which I review her academic qualifications, her link of thoughts and illness, our innate wiring, and the myth of the mini-brain.

Part 2 of this post will look further at the pecking order of the mind and brain, some miscellaneous issues, and her ‘professional’ opinion on ADHD.

Part 3 will examine her claim that “Toxic thoughts are sin” and why such a statement is incongruent with the Christian faith.

IS SHE A COGNITIVE NEUROSCIENTIST?

For a start, she was introduced as a cognitive neuroscientist. Her CV lists her degrees as a Bachelor of Science, Masters in Speech Therapy and Audiology, and a PhD in Communication Pathology. She did not advise where she has tenure or does her research. Her CV lists guest lectures at a few Universities (Wits, University of Pretoria, University of Cape Town, University of Western Cape Annual Education Conference, SASHLA, Rotary Foundation), but no tenure.

Admittedly, the definition of a cognitive neuroscientist is somewhat vague (http://careersinpsychology.org/becoming-a-cognitive-neuroscientist/) but the term ‘cognitive neuroscientist’ confers the idea that one is actively involved in cognitive neuroscientific research, or at least in the recent past.

So the question remains: is she really a cognitive neuroscientist, or is she just a woman with a PhD that reads a lot?

THE CORRELATION OF ILLNESS AND THOUGHT

The next thing to grab my attention was her statement: “75 to 98% of ALL illness is related to our thought life.” Somehow I doubt that. The influence of stress is high.  But I am a GP – I see sick people everyday, on the coal face, before they are collected in subspecialist clinics, or improve spontaneously. It’s a real stretch to ascribe stress to more than 30%. Looking at her book ‘Who Switched Off My Brain’ (Leaf 2009, p15), she says that 80% of all diseases are the result of our thought lives. So her own figures are conflicting. (The other thing is that, for a PhD recipient, she has poorly referenced her book!)

Besides, stress causes illness, but I’m not yet satisfied she’s proven that ‘negative’ thought and stress are the same thing.

THE MINI-BRAIN

She also claimed that the brain and the heart connect to every cell in your body. Again, it’s a bit of a stretch. Every cell needs to be bathed in nutrients from the blood which in turn is connected to the heart, and nerves are every where.  But there are many cells that are not innervated directly.

The only way that the brain or the heart are connected to every cell is simply because, technically, every cell is connected to every other cell. Like if everyone in a church stood up and held hands, the man in the front row would be “connected” to the woman in the back.

But she went further on her theory, by claiming that the heart has a mini-brain that directly influences the real brain – by making moral decisions on its own, and that it is part of our conscience. She justified her statement by saying that the heart has 40,000 interconnected nerve cells, and the heart is directly connected to the brain. But on that same logic, my rectum could be a mini-brain and be part of my conscience.

She alluded to the effect of ANF, atrial natriuretic factor. There are actually three natriuretic peptides. ANF, produced by the top two chambers of the heart, actually regulates blood pressure (http://www.cvphysiology.com/Blood%20Pressure/BP017.htm). If it has an effect on thought, it is secondary, not primary.

WIRED FOR OPTIMISM?

She also states that we are wired for optimism, and that emotions like fear are learned. That doesn’t make sense since I have seen research that shows a newborn baby is wired for pleasure and emotions like disgust. These pathways are developed and refined during childhood, but we are born with built-in templates for basic emotion.

I will have more in the next 24 hours, including her statement on the pecking order of the mind and brain, some miscellaneous issues, and her ‘professional’ opinion on ADHD.

REFERENCES

Leaf, C. (2009). Who Switched Off My Brain? Controlling toxic thoughts and emotions. Southlake, TX, USA, Inprov, Ltd.