Monday, August 8, 2011

Dr. Novella (inadvertently) highlights evidence for Thomistic dualism

Dr. Novella takes me to task:

Next [Egnor] addresses my argument that damaging parts of the brain cause predictable changes in mental function:

[Egnor] I see damaged brains on a daily basis– trauma, tumors, stroke, etc. Sometimes I cause the damage myself (by placing a catheter in the brain to drain fluid). The specific mental deficits are highly variable, not the least predictable and very often there are no deficits at all. I’ve personally inserted at least 3000 catheters into patients’ brains, and I’ve not once seen a change in a mental state from a catheter insertion that passes deep through brain tissue.

[Novella] Wow – this is just stunning coming from a neurosurgeon. Deficits are “not the least bit predictable” from the location of trauma? 
Mental deficits -- specific defects in reasoning, judgement, planning, memory-- are highly variable. One cannot look at a CT scan done after a head injury and predict with any certainty that 'this person will have an inability to remember numbers'. High level mental function localizes very poorly to specific brain regions. This is odd, if, as Novella claims, the material brain is entirely the cause of all mental function.

Other deficits-- paralysis, aphasia, blindness-- are more predictable.

In fact, there is a high correlation between the nature of the neurological function and the extent to which it correlates in a 1:1 relationship to brain tissue:

High-level mental functions correlate very poorly with brain anatomy.

Middle-level functions-- sensory perception, motor function, localization in space, ability to speak-- correlate reasonably well with brain anatomy.

Lowest-level functions, such as nuclei of specific nerves in the brainstem that innervate the head and neck, correlate very closely with brain anatomy.

The rule is this: the higher the level of mental function, the worse the correlation with brain anatomy. Thinking correlates poorly with brain anatomy. Reflexes correlate very well.

As I'll show, this is evidence for a particular version of dualism. It is not evidence for materialism.

... We have now mapped the brain quite extensively. There is a vast experience and literature documenting the close correlation between location of brain injury and specific neurological deficits. It’s hard to emphasize how at odds with reality this assertion by Egnor is.
None of those maps provides any clear pattern of cognitive loss-- meaning loss of specific memories, thoughts, etc-- associated with discrete brain lesions that can be used clinically to predict that loss. There is no 'long division' area or 'enjoy Beethoven' area in the brain that can be mapped with anything resembling precision.

For example, "silent strokes" are strokes that occur without any symptomatic change in neurological functioning. Silent strokes are much more common than symptomatic strokes. 93% of strokes (death of brain tissue) are silent. Only 7% of strokes manifest symptoms. I see these patients on a daily basis in my office and in the hospital. They have multiple (usually small) strokes on CT or MRI and no symptoms that correlate with the loss of brain tissue.

Novella asserts:

           There is a vast experience and literature documenting the close correlation between location of brain injury and specific neurological deficits. 

He grossly misrepresents the correlation, which is not close at all.

...Further – the fact that there is no obvious effect does not mean there is no effect. Unfortunately, there isn’t much research looking at the cognitive effects of catheter placement, but the one study I could find showed, “The present study revealed persistent cognitive inefficiencies in memory and executive domains in patients post-ETV intervention. ”
I've performed ETV's (endoscopic third ventriculocisternostomies) for 20 years, and I've never encountered a patient with a discernible deficit caused by the operation, which entails making two holes in the brain (one in the frontal lobe, one in the hypothalamus). In fact, most patients are better after the surgery (it treats hydrocephalus). And for verification of his crazy assertion-- 'every single prediction of materialism has been verified by neuroscience' Novella quotes one study-- one study! When it comes to materialism, Novella is an easy man to please.

And, as it turns out, he misrepresents the study. The abstract:

Lacy M, Oliveira M, Austria E, Frim MD.
Department of Psychiatry, University of Chicago Medical Center, Chicago, Illinois 60637, USA.
Obstructive hydrocephalus can be treated with an extracranial shunting system or, when the obstruction is between the posterior third ventricle and the fourth ventricular outflow tracts, by an endoscopic third ventriculocisternostomy (ETV). The placement of an extracranial shunting device entails significant long-term risk of infection and malfunction. This risk has led to the concept that ETV is preferable to shunting. While the long-term cognitive performance of shunted hydrocephalus patients has been extensively examined, the outcome of patients undergoing ETV has been studied only sparsely. Ten adults who had undergone ETV were entered into the study under institutional review board approval. Each patient underwent a neuropsychological testing battery that included testing within the domains of basic attention, verbal memory, visual memory, language, and executive functioning. Aggregate test scores showed a decrease in performance in the domains of memory and executive functioning when compared to normative data. The present study revealed persistent cognitive inefficiencies in memory and executive domains in patients post-ETV intervention. A larger longitudinal study considering the impact of prior shunting, presence of headaches, emotional status, and surgical complications will assist in elucidating the etiology and eventual treatment of these deficits.
The study does not demonstrate nor claim to demonstrate cognitive loss caused by the passage of the endoscope through the brain. The authors say so explicitly: "A larger longitudinal study considering the impact of prior shunting, presence of headaches, emotional status, and surgical complications will assist in elucidating the etiology and eventual treatment of these deficits." These patients have hydrocephalus, which causes cognitive deficits, and often have a very complex surgical history. The study does not link cognitive defects in these complex patients to the passage of the endoscope, and in fact they make no mention of it (the passage of the endoscope is not a surgical "complication").

Novella grossly misrepresents the findings of this study, which he admits is "the one study I could find".

[Egnor] further gives the example that he has placed many catheters deep into the brain without causing noticeable changes to the patient’s mental function. What he is not telling you is that surgeons will typically place these catheters through the non-dominant (right side in most people) frontal lobe. There is a reason for this – this is the most redundant part of the cortex. You need to cause damage to both sides of the frontal lobes to cause deficits. The location is chosen specifically to minimize the deficits that result from the procedure. Does Egnor stick his catheters willy-nilly through any part of the brain? I bet not – I bet he follows the standard of care and is very specific about where he places the catheter – because brain anatomy does correlate with function.

Although we do not intentionally pass catheters through areas of the brain known to have unique function (and wisely so), there is evidence that passing a catheter through these unique areas may not cause functional damage in most cases. My experience (5000 brain operations), and the experience of neurosurgeons with whom I have discussed this,  has been that the correlation between brain injury and functional impairment is much less than what has been traditionally believed.

The 'safe' areas of the brain , in which damage does not cause specific functional loss, are called 'non-eloquent' areas of the brain. The dangerous areas of the brain, in which damage causes functional loss, are called 'eloquent' areas of the brain.

In the following diagram:

the non-eloquent areas (where brain anatomy does not correlate with specific function) are in tan, and the eloquent areas (where brain anatomy does correlate with specific function) are the named colored areas.
As you can see, most of the brain mass is non-eloquent and does not anatomically correlate with specific brain function in any precise way.

In fact, one can surgically remove much of the non-eloquent brain without significant discrete neurological deficit. Major portions of the frontal lobes, temporal lobes, parietal lobes, occipital lobes, and cerebellar hemispheres can be removed (and are removed, in operating rooms every day) without substantial specific loss of function.

The materialist assertion that all of the mind is caused completely by the material brain is difficult to square with the routine neuroscientific evidence that many higher mental functions do not correlate well with brain anatomy and often continue to function quite well despite removal of large areas of the brain that 'mediate' them.

The relationship between higher mental functions and brain anatomy remains surprisingly weak, despite a century of neuroscience. Perhaps such a precise relationship will be found, perhaps not. But the fact remains that major regions of the brain that are thought to mediate higher mental function are quite dispensable.

Novella's 'every single prediction of materialism have been verified by neuroscience' is wildly wrong.

Novella has no evidence for a 1:1 correlation between brain anatomy and higher mental function. This evidence is required if materialism is to be supported, because materialism asserts that brain matter is the complete cause of the mind, without remainder. Thus far, for higher mental functions, the remainder is huge, and there is no reason to believe based on the science that a 1:1 reduction of mind to brain will ever be found, especially with regard to higher mental functions such as reasoning.

Dr. Novella's hard materialist dogma is not supported by the science.

Now for the interesting part.

As I stated above, Novella's argument actually strengthens the case for a specific form of dualism called Thomistic dualism. Here's how:

(I will be posting in much more detail on Thomistic dualism soon, and this is just a synopsis.)

Thomistic dualism is the traditional understanding of the mind, dating from Aristotle to the early modern period. It was formulated in the greatest detail by Thomas Aquinas, hence 'Thomistic dualism'.

It is based on a hylemorphic understanding of nature, in which things are composites of matter and form.

Living things are also composites of matter and form, but in living things the form is the soul. The soul in Thomistic dualism is not some spooky etherial thing that looks like a ghost (that's a materialist caricature). The soul is just the intelligible principle of the body-- the aspect of a living thing that makes it 'living'.

There are three general types souls of living things:

Plants have vegetative souls, which mediate nutrition, metabolism reproduction, growth, etc.

Animals have sensitive souls, which in addition to the capabilities of vegetative souls, mediate sensation, locomotion, appetite, etc.

Humans have rational souls, which in addition to the capabilities of vegetative and sensitive souls, mediate reason, judgement, will, etc.

The 'mind', in the modern sense, is mostly the rational powers of the soul. But Thomistic dualists see the mind/soul as a fully integrated principle-- the form of the body.

Thomistic dualists point out that the lower capabilities of the soul-- the vegetative and sensory abilities-- have a strong link to matter. They mediate physiology, movement, etc.

The higher capabilities of the soul-- reason, judgement, will-- are intrinsically immaterial, and have a much less intimate link to matter.

Thomistic dualism predicts the distinction between eloquent and non-eloquent regions of the brain. Some regions of the brain (that mediate 'vegetative' and 'sensitive' functions) have a high degree of correlation between mind (soul) and matter because they are intrinsically material.

Other reasons (that mediate 'rational' functions) have a lesser degree of correlation between mind and brain, because rational powers of the soul-- reason, will, judgement,etc-- are immaterial, and bear a much less intimate relation to brain matter than vegetative and sensitive functions.

This is precisely what neuroscience shows us.

Non-eloquent regions of the brain-- regions in which function correlates poorly with brain anatomy-- are associated with reason and higher mental functions. As reason is itself an immaterial act, the poor correlation with brain anatomy is just what Thomistic dualism predicts.

Eloquent regions of the brain-- regions in which function correlates will with brain anatomy-- are associated with lower functions-- functions other than reason-- such as movement, sensation, vision, etc. Lower functions are material.

The most basic regions of the brain-- regions such as the brain stem and diencephalon that mediate physiological functions such as respiration, homeostasis, endocrine function-- have the highest correlation between function and brain anatomy and are entirely material functions.

The non-eloquent, eloquent, and basic regions of the brain correlate rather well with Thomistic dualism's distinction between rational, sensitive, and vegetative capabilities of the soul.

Thomistic dualism, like materialism, predicts that many functions will have a close correlation with brain anatomy. But unlike materialism, Thomistic dualism predicts that higher rational functions will correlate poorly with brain anatomy, because rational capabilities are intrinsically immaterial.

It is Thomistic dualism, not strict materialism, that is supported by modern neuroscience. As I'll show in future posts, Thomistic dualism also solves many of the quite difficult problems in philosophy of the mind, such as intentionality.

As a careful examination of the mind-body problem shows that dogmatic materialism is bad philosophy and bad science. 


  1. Thomistic Dualism... what is the difference between other forms dualism ??? I never actually got to read much about.

  2. Mortal Kombat continues!

    Actually, Mike, there is a loophole through which Novella can escape. Higher mental functions might be distributed in the brain. There are very nice examples of this in computer networks and in optics. You can take out a substantial fraction of routers and the internet will still function, albeit not so fast.

    Similarly, image formation in a lens is distributed. No specific part of a lens is responsible for the formation of any given part of an image. You can cover half of the length with paper and the entire image will still be there. Brightness will reduce slightly.

    This recent paper presents evidence that the analogy between a brain and a distributed network is not far fetched.

    D. A. Fair em et al., Functional Brain Networks Develop from a “Local to Distributed” Organization, PLoS Comput Biol 5(5): e1000381. doi:10.1371/journal.pcbi.1000381.

    "Abstract. The mature human brain is organized into a collection of specialized functional networks that flexibly interact to support various cognitive functions. Studies of development often attempt to identify the organizing principles that guide the maturation of these functional networks. In this report, we combine resting state functional connectivity MRI (rs-fcMRI), graph analysis, community detection, and spring-embedding visualization techniques to analyze four separate networks defined in earlier studies. As we have previously reported, we find, across development, a trend toward ‘segregation’ (a general decrease in correlation strength) between regions close in anatomical space and ‘integration’ (an increased correlation strength) between selected regions distant in space. The generalization of these earlier trends across multiple networks suggests that this is a general developmental principle for changes in functional connectivity that would extend to large-scale graph theoretic analyses of large-scale brain networks. Communities in children are predominantly arranged by anatomical proximity, while communities in adults predominantly reflect functional relationships, as defined from adult fMRI studies. In sum, over development, the organization of multiple functional networks shifts from a local anatomical emphasis in children to a more “distributed” architecture in young adults. We argue that this “local to distributed” developmental characterization has important implications for understanding the development of neural systems underlying cognition. Further, graph metrics (e.g., clustering coefficients and average path lengths) are similar in child and adult graphs, with both showing “small-world”-like properties, while community detection by modularity optimization reveals stable communities within the graphs that are clearly different between young children and young adults. These observations suggest that early school age children and adults both have relatively efficient systems that may solve similar information processing problems in divergent ways."

  3. Typo: "half of the length" should be "half of the lens."

  4. Mike,
    What a nice post to 'get going' with.
    The correlation between Thomistic Dualism, nature of the soul, and functions of the brain is fascinating. Your real/practical experience with the brain lends it MUCH weight.
    If you're correct, would following this line of reasoning not present us with opportunity to discover new and beneficial aspects of neuroscience? Maybe to refocus a bit?
    I look forward to reading more on it.

    @Oleg, I am not sure what straws your grasping at there, friend....but I will assure you there is not enough of them to build your usual straw man.

  5. so let me see if I get this right Oleg. You saying that the brain will try to use other channels in order to keep those functions going ???

    that is an interesting model, but wouldn't increase the chance to disturb other areas of brain. Let's say, Like Video Game are, I suffer a stroke from playing too much game XD yeah it can happen O_O!!! the brain however uses another channels to keep that function "like video game", intact. But wouldn't that interfere with other functions such as "Like blue". you know like some concepts of the brain wouldd slowly interfere other concepts, slowly changing other concepts.

    Wouldn't the model do that Oleg?

  6. I have to give credit to materialists, they are very persistent. They insist on driving a nail with a screwdriver: it may not be very wise or intelligent, but their persistence is noteworthy.

    They also have a tendency to paint themselves in the scientific corner, like their evolutionary explanation of junk DNA and vestigial limbs, which do not exist. The only problem is that they refuse to admit that they are stuck in their corner because they could not have been able to paint the floor with a screwdriver!

  7. Guys,

    Has any of you read the article I linked? At least the abstract and the author's summary? It is all available online for free. None of your responses addresses the issues I raised.

  8. Oleg,
    I assume you have decided to communicate with me again? This assumption is based on the use of the term 'none', as opposed to neither.
    I am glad.
    Here is my two pennies on your comment:

    I see an argument for design, systems architecture and purpose in that article and Abstract.
    I can see HOW you came to a materialist conclusion of some sort by looking at these recorded observations of researchers in a certain way, but I am not sure exactly what that point is. Is it that the brain more resembles a network of CPU's rather than one? That it more complex that materialists previously thought? you know push back that horizon a bit...
    Maybe I am wrong and you could clarify?
    What I am certain of is that I do not adhere to that monistic view (materialism). I am not limited by it's dogma. The limits of my own dogma are set within the precincts of morality, not reason. I am open minded, and not forbidden any insights by a oracular interpretation of 'science' as so called 'freethinking' Atheists are.
    When I look at what you have there I see the patterns of design, creation, function, and PURPOSE.
    I know you don't see that as I do, and you don't want me to either; but it is there, just as real as you and I.
    That's my thoughts, Oleg.

  9. Also,
    I would pose some questions/challenges to you Oleg (or any materialist) who would care to answer them.
    With specific regards to comments/aticle/abstract above.
    WHY? Not how. That is merely interesting.
    WHY? THAT is important.
    WHY would natural selection prefer higher cognitive function, by allowing it redundancy through back up or networked areas of the brain, and not provide the same or BETTER functions for the essential physical systems like respiration and heart rhythm/function?
    Why would empathy, altruism, taste in music, and the likes get a network of resources when the most basic are easily located and far more easily interrupted with fatal consequence?
    All these questions are important, especially if the above research pans out an proves to be of worth.

  10. PS The link is not working for me.

  11. Here are 2 questions for materialists:

    1) In the future, will computers become conscious and self-aware?
    2) In the future, will computers experience emotions?

  12. Oh damn Oleg XD .... I am too lazy to read the paper now T_T XD.

  13. Oleg,
    Do you care to respond to my points? You asked for our ideas. I have expressed mine and countered with a couple of questions. Do you care to comment on my response or reply to mine questions, or those put forward by Pépé?
    I, for one, would appreciate the academic courtesy.

  14. Here is a web resource to help you understand the funny use of capitals and special characters Edward uses as a matter of fact!

  15. @crusadeREX

    I, for one, would appreciate the academic courtesy.

    I would also appreciate, but I won't bet the farm on it.

    Oleg may be a materialist, but he has an animal survival instinct, provided by evolution, and he obviously sees the danger of venturing an answer in this territory.

    Being painted in the corner holding a screwdriver is very very very uncomfortable!

  16. Dr. Egnor, your blog is in my Favorites.

    If my memory serves me well, you have been a catholic for about 6 years.

    I have been a catholic all my life (i.e. 60y+) and reading your blog as help me more than sunday's mass!

    Thank you and God bless...

  17. Pepe:

    Thank you for your kind words, and your great comments.


  18. I forget you people are not really into Internet talk hhahahah. My bad, I love emoticons, becauseit emulates my reactions in real life n_n.

    * I am still too lazy XD to rea the study Oleg brought hehehhe *

  19. Actually Edward, dropping the XD's and emoticons would make your posts much easier to read.

  20. u_u ohhhh I will try to drop the XD's, but I am gonna be more technical from now on heheh

  21. wow thanks egnor! let me just hop in my delorean and try to explain all of this to phineas gage!

    oh hey phineas, that metal spike had nothing to do with your personality change cuz it was in the non-eloquent part of your brain...maybe god decided you were due for a complete personality makeover and forgot to schedule it for a more convenient time...say, before a major traumatic injury to your cranio-facial areas.

  22. anonymous wrote:
    "maybe god decided you were due for a complete personality makeover and forgot to schedule it for a more convenient time...say, before a major traumatic injury to your cranio-facial areas."
    What is the point of this statement, Anon? I just don't see what you are trying to say. Could you please elaborate?

  23. Just a talking point? Rhetorical device?
    I guess...