Dec 12 2008
Dr. Michael Egnor has written two more posts reiterating his neuroscience denial over at the Discovery institute. This reinforces the impression that neuroscience denial is the “new creationism” – the new battleground against materialism as a basis for modern science. It is important to keep an eye on the arguments and tactics being developed by the DI to deny the core claim of neuroscience, that the mind is what the brain does. This is likely to be an increasing area of attention for the DI and others with an anti-scientific agenda.
Creationists are intellectually dishonest because they are not engaged in a genuine search for understanding, but rather have staked out an ideological position that they will defend at all costs. This applies as well to Dr. Egnor, who is ideologically dedicated to denying the obvious conclusion from the last century of neuroscience – that the brain causes mind.
Specifically, Dr. Egnor repeats points that I have already countered, without addressing my counter points. We are undeniably engaged in a blog discourse – he responds specifically to my blog posts and I reply to his. There is no excuse for not responding to major points that I make against his position. In honest discourse, when one’s point is countered there are three valid responses: acknowledge the counter as valid and revise your position; show that the counter is not valid; or show that the conflict cannot be resolved with currently available information (agree to disagree). The intellectually dishonest or sloppy thing to do is to repeat your original claim without even acknowledging that it has been countered. Creationists have been doing this for decades.
I also have to point out his reference to “his pet theory” when referring to modern materialist neuroscience. This is the same rhetorical tactic as referring to evolutionary theory as “Darwinism” but with extra added absurdity. Neuroscience is no ones “pet theory,” and I certainly do not own it. I do not even claim any originality to the positions I am defending against his denialist attack. I am simply stating my synthesis of the current findings and theories of neuroscience. If I choose to defend plate tectonics from pseudoscientific nonsense, that does not make it “my pet theory.”
The Brain-Mind Hypothesis
In his most recent post Egnor writes:
In the recent past, the Yale neurologist has been so confident of the truth of his materialistic ideology on the mind-brain problem that he has asserted that
“The materialist hypothesis- that the brain causes consciousness- has made a number of predictions, and every single prediction has been validated.”
Leaving aside the hubris (has any reputable scientist ever claimed that ‘every single prediction’ of his pet theory has been validated?), one of Dr. Novella’s implicit predictions seems to have frustratingly failed to materialize.
Egnor is borrowing a tactic of the creationists – deliberately misinterpret scientific confidence as hubris and arrogance. This is a cheap shot, but one that is easy to make to a lay audience. Egnor ignores the fact that I have already countered this claim of his (actually more than once), but I will do it again. He ignores the fact that I spelled out exactly what I meant by “every single prediction” – by actually listing every single prediction and showing that they have in fact been validated. Here they are again.
If the brain causes mind, then:
1- Brain states will correlate to mental and behavioral states.
2- Brain maturity will correlate with mental and emotional maturity.
3- Changing the brain’s function (with drugs, electrical or magnetic stimulation, or other methods) will change mental function.
4- Damaging the brain with damage the mind – producing specific deficits that correlate to the area of the brain damaged.
5- There will be no documentable mental phenomena in the absence of brain function.
6- When the brain dies, mental function ends.
It is my position that all of these specific predictions have been validated over the last century of neuroscience research. It is a cheap debating trick to dismiss my position as “hubris” rather than simply address my points. In fact I would add another prediction to the list, one that I have discussed but have not previously added explicity to the list – if brain causes mind then brain activity and changes will precede the corresponding mental activity and changes. Causes come before their effects. This too has been validated.
Egnor has made several attempts to counter this position, and I have already pointed out that they are all invalid. Egnor has failed to address any of my counterpoints, however. His points are essentially that: 1- correlation is not causation; 2- the brain-mind correlation is not perfect because the brain only mostly causes the mind; 3- materialism has not solved the “hard problem” of consciousness.
Dualism of the Gaps
The second point is easy to deal with – as I have stated, the correlation of brain to mind holds up to within the resolution that we are currently able to measure brain states. Egnor can only point to the fact that when we try to correlate EEG’s (electroencephalogram), for example, to conscious states the fit is not perfect. He has so far ignored my counter that EEG’s are a very low resolution way to look at brain function. As our instruments improve the correlation continues to hold up within the higher resolution. But we are still a long way away from mapping the brain at the resolution of its actual function – the level of neuronal connections.
Also, we have not yet mapped all brain connections -we do not yet fully understand brain function as a system. So we cannot yet fully explain all brain behavior. In essence Egnor makes a “dualism of the gaps” argument, but fails to show positive evidence for a lack of correlation between brain and mind.
Correlation and Causation
Regarding correlation he most recently writes:
No one doubts that there are quantifiable law-like correlates between behavioral states and brain states, and between some brain states and other brain states. But behavior and brain states are objective third person phenomena, the sort science deals with routinely. And behavior is not the same thing as the mind.
What he is saying is that neuroscience can correlate everything it can measure (behavior) to brain function and brain states, but that neuroscience cannot measure subjective experience, therefore it cannot explain it. This is the old creationist tactic of denying the legitimacy of scientific inference. We cannot measure subjective experience, but we can infer it to a reliable enough degree to do science. For example, one of those behaviors that Egnor is referring to is the reporting of subjective states. We cannot measure how much pain a person is feeling, but they can report how much pain they are feeling, and we can make reasonable inferences from those reports.
Here is just one of countless potential examples. Neuroscientists have recently been mapping those parts of the brain that are responsible for the subjective experience that we occupy our bodies – that our “self” is located in the same space as our physical body. We take this for granted, but it is actually a function of the brain, and it can be disrupted.
It is now possible to reliably induce an out of body experience (OBE) by electrically stimulating the left temporal parietal junction (TPJ). (Here is a good recent summary of the research.) The TPJ seems to be involved with bringing together visual, vestibular (sensing gravity and acceleration), and proprioceptive (feeling where one’s limbs are in 3-dimensional space) information to create the sense that we are inside our bodies. It has been shown that having a seizure in the TPJ correlates with an OBE, that stimulating the TPJ can cause an OBE, that imagining onself as floating above the body (in a typical OBE position) correlated with activity in the TPJ, and that inhibiting the function of the TPJ with transcranial magnetic stimulation can block this effect.
Egnor would have you believe that this growing body of scientific evidence only shows that brain states correlate with the behavior of subjects reporting their experience, and not with the experiences themselves. He would have you believe that even if turning on and off a light switch reliably precedes and correlates with a light turning on and off, the switch does not actually control the light – not even that, he would have you believe that the scientific inference that the switch controls the light (absent any other plausible hypothesis) is materialist pseudoscience.
To beat this dead horse a bit – neuroscientists can stimulate the motor cortex (electrically or magnetically) and this will cause the appropriate muscle to contract on the opposite side of the body. If I stimulate the motor cortex that corresponds to the left hand, then the left hand will twitch. Does anyone deny that this bit of brain matter controls the muscles of the hand? If I then destroy that bit of gray matter, the left hand becomes paralyzed. Now – If I do the exact same thing to a part of the brain that controls a specific subjective experience or aspect of personality, such as an emotion or the subjective sense that one is inside the physical body, the resulting correlation is the same. There is no basis to conclude that the motor cortex controls movement but that other parts of the brain do not control subjective experience, unless one denies modern neuroscience.
The Hard Problem of Consciousness
Dr. Egnor has been hitting this theme quite frequently, and yet has not seemed to notice that I have already demolished it. His premise is that neuroscience cannot explain how the brain causes subjective experience, therefore we should conclude that it does not cause (or entirely cause) subjective experience. His premise is dubious and his logic fallacious.
Regarding the premise, I will grant that this is a legitimate point of controversy. In my opinion, Daniel Dennett is correct in that it is adequate to say that subjective experience is an emergent property of brain function. We do not need an explanation beyond that.
But even if I grant to Dr. Egnor that this is controversial (meaning I am not depending upon the emergent property explanation as a premise), his argument is logically not valid. And again, I have already pointed this out and Egnor has failed to respond to my counter.
Interestingly, Dr. Egnor did take notice when the philosopher David Chalmers pointed out his fallacy, although he still doesnt get it. Egnor’s fallacy is this – the ability to explain how A causes B is independent of evidence for the fact that A does cause B. In other words, we can (and do) know with a high degree of scientific confidence that the brain causes mind, even if we cannot explain exactly how the brain causes mind. The lines of evidence I outlined above all establish quite clearly that brain causes mind. Alternate hypotheses, such as the brain as receiver of the mind, do not fit the data, or add completely unecessary phenomena. (It’s possible there is a little invisible elf who turns the light on and off every time I flip the switch, but I don’t think I need to hypothesize one.)
Egnor could not ignore Chalmers because he has cited him so many times as such a wonderful philosophy (I’m not saying he isn’t) because Egnor falsely believed that Chalmers supported Egnor’s Cartesian dualism. I pointed out that Chalmers, in fact, specifically rejects Cartesian dualism (that the mind is made of stuff other than matter) as ridiculous. Chalmers, rather, thinks that there is a higher order physical process at work that cannot be reduced to brain function (and as I said, Dennett disagrees). Chalmers now writes:
The simplest way to see this is to note that the “hard problem” does nothing to suggest that consciousness doesn’t lawfully depend on physical processes, at least in the sense that certain physical states are reliably associated with certain states of consciousness in our world. Even if materialism is rejected, there is still good reason to believe that there is such a dependence, via laws of nature that connect physical processes and consciousness.
Chalmers felt it necessary to specifically state that his philosophical position cannot be used to support intelligent design. Egnor tried to repond to this, but he merely restated his position and did not seem to understand his fallacy, and therefore could not put forward an effective rebuttal. Chalmers states that consciousness is dependent upon natural physical processes, meaning brain function (even if we do not understand how), he just doesn’t think that these physical processes reduce to brain function, while I do.
In other words, Chalmers is recognizing that we can establish that the brain causes mind even if we do not understand how.
All of Egnor’s writing about subjectivity and intention, therefore, is off point. It is irrelevant (a non sequitur) because it does not address the evidence by which we can confidently state that the brain causes mind.
Dr. Egnor’s three pillars of neuroscience denial – dualism of the gaps; denying the inferences from brain-mind correlation; and confusing the question of how the brain causes mind with the question of does the brain cause mind – have all been shattered. He has not acknowledged, let alone countered, these points against his position. He simply restates them over and over.
It’s clear why he is blogging for the Discovery Institute.