"Determined" by Robert Sapolsky

 Robert Sapolsky is a great scientist with deep wisdom to share about humanity.  His recent book, Determined, is another must-read.  

The first half or so of the book details the many factors causing a given behaviour which are outside of what could be called "free will."  For example, hereditary factors, evolved traits, endocrine factors, social and cultural factors, childhood adversity, abuse, poverty, neglect, or discrimination, or on the other hand extreme enrichment through wealth and having good parents, home, and family; and the environmental conditions of the day or the hour.   Sapolsky reminds us, with evidence to back it up, how influential these factors are.  One chapter is dedicated to the Libet experiments, which demonstrate some degree of neural evidence of a decision before a person is subjectively aware of having decided, therefore calling into question whether our sense of making a decision is something like an illusion.  Other chapters are devoted to physics, such as about quantum mechanics and chaos theory; he argues that free will is not to be found in these areas.  

His strongest thesis, which he states a few times in the book, is that even if free will does exist, it is less influential than we believe it is -- that is, we underestimate the impact of other factors.  But often he strays from this strong thesis, into a state of denying the existence of any free will whatsoever, and then reflecting about the moral consequences of this.  

I think in many areas he is overconfident about findings that are quite debatable.  While the many genetic and environmental factors mentioned above are all indisputable, there could be a lot of debate (which he does not engage in) about the magnitude of some of these particular factors, or about the soundness or biases of the existing studies on these matters.  Just as in his previous book (also a great book), Behave, he quotes study data that really ought to be debated vigorously rather than accepted as the final truth on a matter.  In the current book, he even acknowledges these issues with Behave, but then he proceeds to do the same thing again anyways.  I'm not saying he's wrong about these claims, only that he overstates, at least through insinuation, the certainty of the evidence supporting them.  

 In quantum mechanics, for example, the most common view is that events in the quantum realm take place in a truly random fashion; such randomness eliminates the possibility of deterministic precision.   At the very least, there may be certain deterministic statements that are almost undeniably true (such as that you or I will die in less than 100 years; or that the sun will enter a red giant phase in several billion years), but there will always be a shadow of uncertainty around the specifics, or even the tiniest flicker of uncertainty about the event itself; some of this uncertainty is not due just to incomplete information to make a prediction, it is fundamental to physics itself.     Such quantum events I think are relevant to human events, as for example they could determine whether a particular DNA mutation takes place at a particular time, with very important consequences regarding an individual's survival, disease state, or passage of genes to the next generation.    Mind you, I discovered one group of physicists espousing an idea called "superdeterminism," which accounts for some of the peculiarities of quantum experiments (such as those dealing with Bell's inequality) by positing that apparently random quantum events are all completely determined, thus one cannot actually modify an experiment in a truly arbitrary manner, since the decision about the supposedly randomized experimental manipulation was already completely determined in advance.  Yet, I think we would have to agree that this is far from a settled matter in physics, and we would need to step back from making strong claims about this area.  

The strongest conclusion Sapolsky makes based on his thesis about determinism is that we therefore need to be more empathic and gently understanding about all human behaviour (of course, his thesis really takes away the possibility that we could somehow "choose" to be more understanding, since if this empathy occurred it all would have been determined in advance).  The best we could do to analyze this moral issue, while accepting his thesis of an absence of free will, is to consider an ideal moral code (in some kind of Platonic "realm of forms") which would have optimal fairness and justice.  This is in fact what moral codes, including those in the legal system, strive to do.  But in the light of our knowledge about free will, what changes if any would be best in terms of modifying moral or legal rules?  

He argues that dealing with criminal behaviour in a blaming or punitive manner is not rational, since the causes for crime have been determined not by the individual's "free will" but by genetic and environmental factors outside that person's control.  He similarly argues that praising people or celebrating great accomplishments is irrational, since the accomplishments, or capacity for hard work, etc. were also determined by factors outisde the individual's control.  So basically when we congratulate someone for a great accomplishment,  we are granting the person credit for factors that were really the product of millions of years of prior good luck.  

But of course, is this how we would really want to live?  To stop congratulating people after they do good things?  Or to always be meekly understanding when people do terrible things?  I agree with Sapolsky that improved scientific understanding about causality should prompt us to be more humble, and to be less inclined to reflexively blame or punish bad behaviour while motivated by reflexive emotions.   

But part of normal life involves congratulating people.  Admiring accomplishment is like admiring beauty in nature.   Maybe there should be a little bit of humble acknowledgement of those factors that contributed to the accomplishment outside of one's own "free will."  But this is part of the etiquette in almost any awards ceremony, though most people don't go into remote evolutionary causes for their good fortune--they tend to stop at family, friends, and teachers.  

Sapolsky cites various egregious examples of recklessly excessive violent punishments through history, leading to his own stance of advocating leniency in the justice system.  He has a very admiring tone around Norway's approach to having what most in the world would consider a shockingly lenient prison sentence for a notorious mass murderer.   While there is much to admire in Norway's civilization and justice system, I think this practice of strictly limited sentencing fails to address a massive component of consideration in criminal sentencing, which is the psychological impact of the sentence on victims, and families of victims (who are also victims) of the crime.  A reason to keep a mass murderer in custody permanently is to treat and prevent anxiety and distress among victims or families of victims.  It need not be motivated by our base (but highly evolved) urges to punish, or by irrational overestimation of subsequent criminal risk (scientific estimates of recidivism risk should obviously impact management of criminal offenders, though the accuracy of recidivism risk estimation is way less than 100%). It should definitely be influenced by considerations of the impact of the sentencing on the health and psychological well-being of victims.  

So all in all, a very important and impactful book.  I have to admit I find it disturbing to know that "free will" even if it does exist, is rather less complete in determining behaviour than most of us believe.   But in dealing with scientific findings, we need to be prepared to consider things if the evidence supports them, even if the findings might be disconcerting.

How does this book guide our understanding of mental health, or of therapies for mental health problems?  For one thing, we should be reminded to reflect on our tendency to be reflexively judgmental, or to blame people for what could be seen as failures of will.  If we do engage in judgment or blame, it should be guided by rationality, as to whether this would be helpful to improve the situation for all.  Often such blame or judgment is not actually helpful.  Arguably some forms of blame could be a normal motivational influence in humans, but probably we use this too often and too heavy-handedly.  

Omega-3 deficiency and low dietary omega-3 to omega-6 ratio may exacerbate depression and reduce neuroplasticity

Here's an interesting update on the dietary fatty acid issue, as it pertains to mood disorders and neuroplasticity:
http://www.nature.com/neuro/journal/vaop/ncurrent/full/nn.2736.html

This article, published in Nature Neuroscience (January 30, 2011), is an example of some good research being done by a group at the University of Bordeaux in France.  They demonstrate substantial negative neurophysiological changes in mice as a result of an omega-3 deficient diet.  It is interesting to note that the brain's endocanniboid system is specifically affected by omega-3 deficiency, according to this research.

This is further evidence supporting the importance of attending to a healthy diet, in maintaining optimal mental health.  Omega-3 fatty acids are one element of a healthy diet.  While omega-6 fatty acids are also needed in the diet, these lipids behave to some degree competitively with omega-3.  Therefore,  the ratio of dietary omega-3 to omega-6 is is very important.  Western diets tend to have an unhealthy ratio of these lipids, due to excessive omega-6. 

An ongoing issue of debate has to do with whether plant sources of omega-3 (primarily ALA) are as useful as fish sources (DHA and EPA).  Existing evidence shows that DHA and EPA are more important.  ALA can be converted in the body to DHA and EPA, but the efficiency of this may vary from person to person.

Wikipedia has a nice review of this subject: http://en.wikipedia.org/wiki/Omega-3_fatty_acid
but some of the sources are less than ideal.

It is interesting to consider that the DHA/EPA issue is not a "micronutrient" issue.  They could be considered  "macronutrients."  The solid mass of the brain consists mostly of lipids (60-80 % of the non-aqueous mass); DHA and EPA  make up over 10% of this lipid mass, which is a very high concentration.


Here's a link to a paper which quantifies the  high fractions of omega-3 lipids in brain mass:
http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=921064   --this paper also showed that dietary changes substantially altered the proportion of omega-3 lipids in brain tissue

Doidge (Neuroplasticity) review - part 3 (Schwartz)

Doidge devotes a chapter to discussing obsessive-compulsive disorder. He claims that a treatment developed by Jeffrey M. Schwartz is "plasticity-based". The implication is that other psychological treatments for OCD are NOT "plasticity-based."

Schwartz has published articles in the literature going back into the 1980's looking at OCD patients using PET imaging.

I do not find any good study in the literature about Schwartz's particular technique, as published in his book, in particular no study comparing his technique with CBT.

Also the theory is presented that OCD is caused by a failure for the caudate nucleus in the brain to "shift gears automatically", and that the therapy described is a means of "shifting gears manually." While there are a variety of brain metabolism changes in OCD, I think it is an overly strong statement to believe that this is literally true. One could use the idea of the "caudate gear box" as a metaphor, but it may be quite inaccurate, or at least poorly supported by clear evidence, to be taken literally.

So it concerns me that the chapter in Doidge's book about the "brain lock" approach is more of a book plug than something founded on solid evidence. Doidge could well have made the case that CBT is a type of "neuroplasticity-based treatment". In fact, there is good data to support such a case--including numerous imaging studies--and including a recent paper which Schwartz himself co-authored, which shows various regional changes in brain metabolism associated with improvement in OCD symptoms from intensive CBT:
http://www.ncbi.nlm.nih.gov/pubmed/18180761

Yet, I think it is important to be open about any new therapeutic idea--it may be that the "brain lock" therapy for OCD could be helpful to many people. It's just that Schwartz's book has been given an endorsement by Doidge without a convincing amount of good evidence, while minimizing the robust evidence favouring CBT.

Doidge (Neuroplasticity) review - part 2 (Taub)

Doidge devotes a chapter to the work of Edward Taub. I think Taub's ideas are simple but brilliant. He developed a treatment called "constraint-induced movement therapy" which appears to be remarkably effective to help with recovery from strokes and other injuries.

The simple idea is to restrain the normal limb, almost continuously, for at least weeks at a time, after a neurological injury. Otherwise, the normal limb will compensate for the affected limb. If the normal limb is constrained, the brain itself will develop new pathways to improve the function of the affected limb.

This treatment has good evidence-based support:

http://www.ncbi.nlm.nih.gov/pubmed/18077218

{this 2008 study is from Lancet Neurology, one of the top journals in neurology}

http://www.ncbi.nlm.nih.gov/pubmed/17077374

{another very important study from 2006 in JAMA}

I'm curious about the applications of this sort of therapeutic idea to psychiatry. Psychiatric symptoms can be like other neurological impairments, and the psychoanalytic phenomenon of "defences" may be analogous to the tendency for a neurologically-injured person to favour the non-affected limb, while the affected limb loses more and more function. A psychological therapy which challenges defences may be something like a Taubian "constraint-induced movement therapy" for the mind.

Importantly, in order for Taub's therapy to work, the constraint has to be applied almost continuously during waking hours, for at least weeks at a time. It is an immersive experience. It is an interesting challenge to find more psychological therapies that can be "immersive" in this way.

Doidge (Neuroplasticity) review - part 1 (Merzenich)

This post begins my review of Doidge's references from his book on neuroplasticity.

The first references I have looked through pertain to the work of Michael Merzenich. He has done very interesting research, dating back 4 decades, a lot of it having to do with studying the auditory cortex, and how it changes in response to stimulation of various sorts during different phases of development. Also he done major work researching and developing cochlear implants for treating hearing loss.

His 2006 article about using a "brain plasticity based training program" to improve memory in older adults (http://www.ncbi.nlm.nih.gov/pubmed/16888038) is interesting and encouraging, yet it warrants a close look at the actual results: the memory improvements from this technique were very modest (though significant), also the control groups were both quite passive (one group just looked at DVD videos, the other had no "intervention" at all). It would have been much more interesting to me to see an active control group in which the individuals would be doing simple memory exercises or other active intellectual stimulation for the same length of time. Because this type of active control was absent, the results may aggrandize the specific form of skill training described in the study; this skill training regimen is now being marketed, and money is surely disappearing from the pockets of many people, including many elderly people who may not have an abundant financial reserve. This makes me especially less enthusiastic about the results. I have no doubt that active mental exercise changes the brain through "plasticity" but I have to wonder if we have to sign up for the deal ("save 20% and get free ground shipping!") with this specific technique to achieve this. Perhaps signing up for a book club, memorizing poetry, and playing chess daily, would accomplish similar results. I would like to see what the evidence has to say about this. His website is interesting to look at, has a few mental exercises to check out, the style of which I think really is quite positive and imaginative. I will be curious to see if his approach--and variations of it-- could be specifically helpful in treating disorders such as autism. But I don't see good clinical data out there yet.

As an amateur musician, I have found that "ear training" is probably the most important, but often least taught or practiced, form of mental development for improving musicianship. Merzenich's exercises clearly focus on "ear training" as a significant component. Here's his website for you to check it out yourself: http://bfc.positscience.com/

Here's a link to a program you can acquire, designed for music students, which develops musical ear-training ability much more thoroughly, in my opinion (I recommend this to all musicians): http://www.earmaster.com/

Neuroplasticity

This is an important book which I highly recommend:
The Brain that Changes Itself, by Norman Doidge (Penguin, 2007).

Doidge is a psychoanalyst who has done a fine job compiling evidence from recent neuroscience research, and from some older but neglected neuroscience research, that the brain has a tremendous capacity--a capacity which is arguably its most basic, core, innate quality-- for change and adaptation.

The idea of the brain as permanently "hard-wired" is refuted, with solid evidence.

Many of these ideas I have always felt to be obvious truths. For example, it seems an obvious necessity that the brain would have to build new connections in order to form any new thought, experience any new feeling, store any new memory, learn any new skill. But the degree to which whole areas of the brain can "re-wire" themselves is extremely interesting, and the evidence Doidge presents is very convincing.

Also, it has always been an obvious truth to me that any kind of sensitive neuroimaging device would of course demonstrate changes following a successful course of therapy (or of any other sort of learning or substantive life change).

The therapeutic applications based on this book are numerous, here are a few I can think of:

1) structured, intensive practice could lead to far greater effects than what has previously been assumed. The brain itself, as well as people in society, informed by culturally-based attitudes, tend to "work around" problems if the situation allows, whereas it can be the case that the problems themselves can be solved directly under the right conditions. For example, if an English-speaking person moves to a small town in a foreign country, that person will quickly learn that new foreign language, if it is necessary in order to survive. But if there are numerous English speakers in that small town, that person may not learn much of the new language at all.
We may need a type of immersive, constrained experience in order to compel our brain to develop a new faculty.

2) structured, intensive activities that have become part of a cultural norm (e.g. internet use, TV watching, etc.) could substantially alter the brain's connectivity and functionality, to optimally adapt to these new media. This could serve us well, culturally--but it may come at a cost of reduced functionality in media away from the TV or internet, particularly with respect to sustained attention, other intellectual and emotional faculties, and various types of social interaction.

3) Addictive processes are fed by the brain's capacity to adapt, to "re-wire" itself to expect a frequently reinforced behavioural pathway. "Un-learning" addictive behaviour once again may require a massive amount of work, akin to learning a new language.

--I have yet to review all of the references cited in this book. I think the primary source data will be important to go through in detail. There are some areas and claims that I think may possibly be overstated, in my opinion. But first I would like to review the evidence directly. I actually find the term "neuroplasticity" somewhat annoying, especially when therapeutic ideas are labeled "neuroplasticity-based treatments", etc. --I would say in response that ALL therapy, of ANY sort, is of course "neuroplasticity-based", so such lingo is unnecessary, and rings of salesmanship to me (indeed, there are several corporate ventures mentioned in the book). What matters most is the new types of therapeutic ideas that have been conceived by some of the researchers cited in the book, and how well they can work for very entrenched problems.


In the meantime, I do recommend Doidge's book highly.

Brainstem Stimulation - cranial nerves

There are some novel therapies such as vagal nerve stimulation or deep brain stimulation, which can improve symptoms of depression. These treatments may be increasingly important sources of relief for chronically suffering depressed patients-- particularly as the technology advances, becomes safer and more refined.

Here are a few links to references about these treatments:

http://www.ncbi.nlm.nih.gov/pubmed/16641939

http://www.ncbi.nlm.nih.gov/pubmed/19137233

Of greater interest to me in an outpatient office psychiatry practice, is an idea based on looking at trivially available techniques to accomplish "deep brain stimulation" or "vagal nerve stimulation", etc. All parts of the brain -- even the "deep brain", and even the vagal nerve -- are connected to all other parts of the body! Specific life events can obviously affect deep brain or vagal nerve stimulation, without requiring an implanted electrical device or neurosurgery! Some of these life events could be deliberately sought out as therapeutic strategies.

Something I've noted about some of these new, radical techniques, is that they involve stimulation of brainstem structures, often involving the cranial nerves. It seems to me that the cranial nerves are an extremely visceral set of portals through which stimuli are exchanged between the environment and the deep structures of the brain which regulate mood and consciousness. Here's a summary of all the cranial nerves, with speculations about techniques to "stimulate" them in a way that might be therapeutic:

Cranial Nerve I (olfactory): Stimulation of this nerve requires exposure to different scents. Aromatherapy is a familiar component of alternative health strategies. Here is some evidence from the mainstream medical literature, showing that aromatherapy can be helpful:
http://www.ncbi.nlm.nih.gov/pubmed/19125379
(a review article)
http://www.ncbi.nlm.nih.gov/pubmed/18178322
(a randomized study showing that the scent from lemon oil improves mood, compared to water or lavender, and regardless of expectancies or past experience with aromatherapy)
http://www.ncbi.nlm.nih.gov/pubmed/18713168
(a study showing improvement with lavender oil aromatherapy vs. controls in neuropsychiatric symptoms of elderly dementia patients)
http://www.ncbi.nlm.nih.gov/pubmed/17342790
(another study showing improvements in dementia patients with lavender)

Given the fact that there is virtually no risk to aromatherapy treatments, why not give it a try? It could help with sleep, relaxation, studying, or as a conditioning device (e.g. associating a particular odor with sleep, or with studying a particular subject, etc.)

Cranial Nerve II (Optic): Bright light therapy has a considerable evidence base. Probably looking at beautiful things in nature is good for your mood (I'll need to find a reference to prove this!). These images would have to pass through Cranial Nerve II, on their way to your brain.

Cranial Nerves III, IV, and VI: these innervate the muscles which move the eyes. There is a type of therapy called "EMDR" which calls upon patients to move their eyes back and forth as an essential part of the therapeutic technique. I suspect this acts as a conditioning phenomenon, which at once distracts the person, while perhaps permitting exposure therapy regarding uncomfortable thoughts or PTSD symptoms to take place in a more relaxed state, or in a state associated with therapeutic benefit. But maybe the "brainstem stimulation" from eye movements is an integral part of EMDR's therapeutic effect.

Here are some links to review papers or meta-analyses looking at EMDR:
http://www.ncbi.nlm.nih.gov/pubmed/16740177
(here, EMDR and CBT are both shown to be substantially and similarly effective in the treatment of post-traumatic stress disorder)

http://www.ncbi.nlm.nih.gov/pubmed/17636720
(a Cochrane review also showing EMDR and CBT to be the psychological treatments of choice in post-traumatic stress disorder)


Cranial Nerve V (trigeminal): this nerve transmits tactile sensations from the face into the brainstem. I do not know of any deliberate psychiatric therapy involving this nerve. But there is acupuncture. Also, there is massage, and in particular "facial treatments" (involving massage, aromatherapy, moisturizing creams, etc.) available in health spas--these seem to have a positive effect on overall well-being. I'd be curious to see a controlled study on this: in the meantime, though, it seems another risk-free thing to try.
http://www.ncbi.nlm.nih.gov/pubmed/19129675
(well, this is a pretty weak study -- but it's a start, and it involves a totally harmless treatment -- it shows reduction of anxiety in women receiving facial massage)

Cranial Nerve VII (facial): this nerve innervates the muscles of the face. As noted in a previous post, actions which affect facial musculature can affect emotion, just as emotion changes facial muscle tone (it's always interesting how these phenomena can work both ways). A branch of Nerve VII also conducts information about taste (gustatory sensation) from the tongue to the brain. I have no doubt that enriching one's culinary sensations in life has a positive impact on mood. But I'll have to look for a study to prove it.

Cranial Nerve VIII: the cochlear branch of this nerve transmits information about sounds from the ears to the brain. Hearing music, soothing sounds, and speech clearly affect mood and cognition. Noise, as I claimed in an earlier post, has a negative impact on mental health. Silence itself "rests" the cochlear nerve, which could itself be therapeutic (in moderation).
The vestibular branch of nerve VIII seems interesting to me as a prospective therapeutic target. This nerve transmits signals about balance, head position, and head movement to the brain. Sometimes individuals in an autistic or highly agitated psychotic state will stimulate their vestibular nerve by rocking repetitively. The action of a parent rocking a baby to sleep, or calming an agitated, crying baby, involves stimulating the baby's nerve VIII. It would be interesting to see if various stimulations of the vestibular nerve could be useful in adults, to treat anxiety, agitation, insomnia, or mood disorder. Balance exercises could be a start (perhaps some of yoga's therapeutic effects come from this). Maybe something like sleeping in a hammock, which would rock slowly, could be more soothing on this level, compared to a regular bed. Some people might find a boat to be very soothing (for others it would just cause nausea). If there are any engineers out there, reading this, it would be an interesting project to design a device which could be programmed to gently rock an adult back and forth (with different waveforms and frequencies).

Cranial Nerve IX: Glossopharyngeal. This nerve innervates your throat. The action of swallowing involves this nerve. People with anxiety states often have uncomfortable throat sensations, or problems with swallowing. It's hard to come up with therapeutic ideas directly relating to this one. Except perhaps the idea of eating really spicy food -- which stimulates not only taste buds but also sensory nerves (partly from Cranial Nerve V) in the mouth and throat. Strong culinary sensations can be a source of pleasure, and perhaps can also teach one to be more open about new things (I remember taking a long time getting used to wasabi on sushi after being introduced to Japanese food upon moving to Vancouver in 1995).

Cranial Nerve X: This is the vagus nerve that is stimulated electronically in an advanced surgical treatment for depression. The vagus nerve innervates the parasympathetic system of the body's viscera (e.g. it slows the heart, speeds up the bowel, etc.). One can train the vagus nerve through activities such as yoga, meditation, biofeedback, and through physical exercise.

Cranial Nerve XI: this nerve allows you to turn your head back and forth. Perhaps this could be an element not to forget in your exercise regime -- do some stretching and gentle exercises involving rotation of your head.

Cranial Nerve XII: this nerve allows you to move your tongue. Speech, singing, eating, and a variety of other pleasurable activities -- all involve your tongue. In anxiety states, people can have an exaggerated awareness of their tongue movements. Taking voice lessons or attending a voice coach can help build confidence, reduce social anxiety, literally help you "strengthen your voice"--a strong and clear voice, both metaphorically and literally, can be part of a healthy emotional life.

In conclusion, perhaps there are a variety of readily available techniques that can accomplish "deep brain stimulation" in ways that benefit your mental health, without actually requiring a neurosurgical procedure!

Neuroimaging Research

I think modern technology is wonderful.

We now have machines which can image the living brain and measure activity in different parts of the brain as events are happening.

Whenever there are interesting new measuring devices, there will be many research scientists who will compete for time on the machines, to conduct experiments.

In psychiatry, brain imaging has been an active area of research. Most every week there is something in newspaper headlines about brain imaging findings pertaining to human emotion, perception, personality, or behaviour.

I think such studies will eventually help guide us to understand and help a greater variety of problems, perhaps in a more proactive and specific way.

But, in my opinion, we are not nearly there yet. Functional imaging has few practical applications. And, in the excitement about seeing something light up on a computer screen, people are suspending common sense at times.

For example, the other day I was reading an article in the paper, which was citing an imaging study apparently showing that people had less empathy for those struggling with addiction, compared to those with other problems.

I would not doubt that many people truly do have less empathy for addicted indididuals. But in the article, the "proof" that people had less empathy was that some area of their brains, when scanned, showed less activity, when contemplating scenes depicting individuals with addiction problems. This imaging finding was used as a rhetorical device in the article.

This reminds me of trying to determine if people outside believe it is daytime or night-time, by making them wear hats that have solar panels on top, and measuring the intensity of light picked up by the solar panels during the day.
--i.e. such measurements are indirect, imperfectly correlated, and absurdly unnecessary--
People may certainly believe it is daytime when the solar panel is picking up the strongest signal. But does that mean that this evidence from the solar panel data is somehow more intellectually superior to simply asking the person what they think? The most direct measure is to ask the person outside "do you think it is day or night"? The solar hat is just silly. However, it might at times pick up a situation in which someone is lying or unaware. Even then, such a finding would merely warrant further investigation, and would hardly constitute proof of anything.
--

It is an obvious truth that changes in thought, emotion, and behaviour, will correlate with, or be the result of, changes in brain activity. Yet it is NOT an obvious truth that a change in regional brain activity--particularly with the relatively crude spacial and temporal resolution permitted by today's technology-- proves that there is a particular change in thought, emotion, or behaviour, or that such measures of brain activity have higher levels of validity than simply having a conversation with someone.

I worry that findings from machine-generated data may so dazzle the audience that it causes unwarranted persuasion to occur, despite the findings being vague or associative. People tend to be impressed by colourful pictures made by expensive machines. We can't let this kind of phenomenon cause us to suspend critical judgment.

A related example of this leaps to mind, in pharmaceutical marketing. There has been a lot of competition out there, in past decades, for companies selling antidepressants and antipsychotics. Typically, in a sales spiel, for a given drug, there would be information given such as:

"most receptor-specific"
or "dual mechanism of action"
or "highest potency"

These facts would certainly be true, and they would have the evidence to prove it. But -- the evidence does not actually exist that these facts are clinically relevant. Whether a drug is "receptor-specific" or not may not really matter at all in terms of how well the drug works. In fact, some drugs such as clozapine, are not "receptor specific" at all, yet work better than the others in its class. "Dual mechanism of action" actually refers to a drug affecting two different receptors (hence, actually it would be less "receptor-specific" yet the phrase is still used as a selling point). Venlafaxine is often marketed this way. Whether or not venlafaxine is a superior antidepressant because of its "duality" is hardly proven, yet the marketing catch-phrase can be compelling to many. And "highest potency" is almost always clinically irrelevant. A drug with smaller "potency" can simply be dosed differently, so that it produces the same effect as a "high potency" drug.

I wholeheartedly support ongoing imaging research, yet I think we need to be careful about inferring too much from the findings at this point.

Scaled-up Structure of a Neuron

I'm always interested in analogies & thought experiments. One of them last year was to consider the following:

What would a brain cell (neuron) look like on a vastly expanded scale, where the body of the cell (cross-sectionally) would occupy an area about the size of a small urban residential lot (let's say about 10 x 40 metres, or 35 x 120 feet)?

Interestingly, it took a fair bit of effort to get an accurate picture of this (and even now, I'm sure I could get into a lot more detail). Advanced textbooks of neuroscience may be good at describing a lot of fine details, but they tend not to give the reader a good visual picture of what the brain -- or a neuron -- in action -- really looks like. In order to do this research, it involved digging at length into the neuroscience literature (full references are available to the interested reader).

Here are some of my findings:

A typical neuron cell body is about 20 microns in diameter (about 1/50 of a millimeter). If the cell body were made into a giant which occupied a whole city residential lot, we would be scaling upward by a factor of about 1.85 million.

At this scale, a single atom would be about 0.2 mm wide (well within visual resolution). At this scale, your head would be about 340 km in diameter. This is about the size of a U.S. state such as Ohio, Pennsylvania, or Louisiana; or almost as large as the Canadian provinces of New Brunswick and Nova Scotia combined.

Dendrites are arm-like extensions of a neuron's cell body. Dendrites can be up to 600 microns long, and on our scaled-up neuron, this makes the longest dendrites about 1 km long. Each neuron can have about 20 dendrites. Each dendrite in our model would be about 5 meters wide. In our model, dendrites are similar to the width of streets or alleys coming away from the yard (remember this is really in 3 dimensions), and each street or alley would extend to some outer reach of your local neighbourhood. Inside each dendrite are many mitochondria (the "power plants" of the cell), each of which about 4 x 1 meters in size (each about the size of a hippo).

There are fibers holding the whole cell together (and serving other functions), called neurofilaments and microtubules. They are typically about 10 mm in diameter in our model (like a medium-sized rope), and are spaced about 100 mm apart (so the inside of a neuron could get quite tangled up were it not for the fact that these "ropes" guide everything along smoothly, acting as miniature pulleys and motors).

A synapse is an area where two neurons communicate chemically. There are thousands of synapses on each neuron. In our model, each synapse area would be about 1 meter wide. The distance across the synapse (between neurons) in our model is about 180 mm (6 inches). Nerve cells release vesicles into the synapse containing neurotransmitters such as serotonin and norepinephrine. In our model each vesicle would be about the size of a small grapefruit. Each time the neuron is fully activated, about 300 of these grapefruit-sized vesicles would be released. Smaller activations of the neuron would cause only 5-10 vesicles to be released. After release, the vesicles are "recycled" within about a minute.

If there is a drug such as an antidepressant affecting the neuron, its size on our model would be something like a grain of sand. Concentrations of antidepressants in the brain are something like 1 in 6 million. This corresponds to one, or just a few, molecules of antidepressant -- each one the size of a 1 mm grain of sand -- in every cubic foot in our model. This shows us visually that just a tiny amount of something in the brain can have a powerful effect.

In the actual brain, neurons are "packed" with a density of about 100 000 per cubic millimeter. In our model this corresponds to neurons packed roughly equivalent to how the city lots are "packed" in a residential neighbourhood (but in 3 dimensions).

The brain's surface area, scaled up for our model, would occupy an area about the size of Washington state, or of southern British Columbia, all of which occupied by "houses" or "yards" corresponding to individual neurons (but in the real brain, there are 3 dimensions, of course). The "houses" would be locally connected through dendritic connections in areas corresponding to residential "neighbourhoods". And there would be many axonal connections linking these neighbourhoods to the far reaches of the brain's territory.

The total population of neurons in the brain is about 100 billion, which is 15 times the population of humans on the earth.

Consciousness

I should caution the reader that this particular post is less directly related to psychiatry--it's more of what I would call a "philosophical musing". So you may want to skip over this post if you're not in the mood for it. But it's something I've thought about for a long time, and I find themes pertaining to it coming up frequently in my daily work.

Consciousness is miraculous.

It may be (actually this is exactly my view), that from a scientific point of view, consciousness is the product of chemical and electrical signals in the brain, influenced by both internal and external stimuli, forming an integrated network with numerous complex feedback loops. Regardless of the causes of consciousness, it remains miraculous that any physical process could give rise to a subjective experience of awareness.

The issue of free will is related. Even if we claim that free will is an illusion, that all choices are determined by the existing structure of the brain in combination with environmental events, and furthermore that brain structure and environmental events are themselves determined by historical precedents (perhaps with a degree of true randomness at the core of physical phenomena rendering all of these processes imperfectly predictable), the awareness of having -- or seeming to have -- free will is also miraculous.

Clearly there are "degrees" of consciousness. Human awareness can vary--or be changed pharmacologically--from full alertness, or hyper-alertness, to many degrees of sedation, to unconsciousness. Apparently absolute unconscious states may only be relatively so, since some degree of stimulus may produce a response even in people who are sleeping deeply, anesthetized, or comatose. As we agree that there are degrees of consciousness, how sure can we be that there is an "absolute zero" where there is no consciousness at all?

If awareness or consciousness is the product of the brain, and the brain's function is a property of a network of chemical and electrical connections, then it may follow that any system in which there are chemical or electrical connections carries a form of consciousness. It seems grandiose -- on the part of humanity -- to claim that the human brain is the only structure capable of conscious awareness or the perception of will.

Most people would have no difficulty asserting that higher animals are conscious, though most (I included) would say that the consciousness of animals is "lesser" than that of humans. At the most obvious level, we can say that the intellectual and language feedback which enriches our conscious experience is much reduced in animals, such that very little cultural development over different generations is possible in non-humans. Another "thought experiment" type of question would be, who is MORE conscious, a fully alert dog, or a heavily sedated human? I guess many would say that there are "types" of consciousness, and that the "human" type is qualitatively different than "non-human" types, irrespective of the degree of alertness or sedation, etc.

Fewer people would claim that simpler animals are conscious.

Very few people would agree that plants are conscious.

Almost nobody would agree that rocks are conscious.

I claim that all of the above may be "conscious" in a way. I do not mean to sound mystical at all here, just extending the logic that if chemical or electrical connections in a network give rise to consciousness, then perhaps any systems of chemical or electrical connections that form feedback networks are also conscious. Therefore, all of the universe could be considered "conscious". A rock could be considered "conscious" since it is intimately linked -- chemically and electromagnetically -- to its environment, and both disintegrates and incorporates environmental elements continuously during its lifetime (obvious changes in chemistry and magnetism perhaps taking place over thousands or millions of years--an example of how some forms of "consciousness" may involve different time-scales than what we are used to).

A corollary of the above could be that since consciousness is a product of networks of chemical interaction, then all conscious beings are "interconnected", perhaps part of a higher-order consciousness. A simple example of this would be to look at politics. Often times we refer to nations as though they are people. We talk about "what Russia is thinking", or about "U.S. arrogance", etc. While this is figurative language, there is a level of literal truth, I suppose, to consider that a nation itself represents a higher form of consciousness, or could at the very least appear to be a higher form of consciousness to an external observer (i.e. someone who did not realize they were communicating with a nation instead of with a person).

I am not saying that this therefore makes it rational to start singing songs to the rocks to soothe them, or to embrace some kind of animistic belief system where we deify or personify plants, mountains, planets, gemstones, etc.

But I hope this line of thinking may cause us to extend respect and caring to all things. Fellow humans. Fellow animals. Fellow living things. Even inanimate objects. The earth. The air. The soil. Your home. Your room. Your belongings. Other people's belongings. Objects that have been thrown away. And, going inwards, to all the different parts of our body (many of which, ironically, are as inert or "dead" as stones, but still require care -- for example our teeth, hair, epidermis, or nails). Going inwards further, on an even more abstract level, your feelings, your thoughts, and your life history, all deserve respect and caring.

The act of respecting and caring for ourselves is part of healthy living. I think this respect and care can be extended to all aspects of the environment around us.

And, on a slightly mystical note I suppose, I wonder if there is something about respect and care that is always mutual--so I wonder if the universe can, on some level, always perceive, understand, and reciprocate such care. This is sort of a "karma-like" idea.

Stepping back from a mystical note, though, I think there is solid psychological evidence to support the idea that caring and respecting as a way of life is part of staying healthy and happy.