Why His Book on Unusual Brains Skips All the Best Cases

The book The Disordered Mind by neuroscientist Eric R. Kandel is a book about unusual brains, as we can tell from the subtitle “What Unusual Brains Tell Us About Ourselves.” But there is a reason the book does not tell us about any of the more interesting cases of unusual human brains.

On page 5 Kandel states his materialist assumptions, and tries to back them up by referring to some experiments he did with some small marine animal called Aplysia. He states the following:

The brain can achieve consciousness of self and perform its remarkably swift and accurate computational feats because its 86 billion nerve cells –its neurons – communicate with one another through very precise connections. During the course of my career, my colleagues and I have been able to show in a simple invertebrate marine animal, Aplysia, that these connections, known as synapses, can be altered by experience. This is what enables us to learn, to adapt to changes in our surroundings.

You do nothing to explain higher human mental abilities by saying that they are the product of neurons, no matter how many connections you may imagine between such brain cells. We should not think that brain cells are capable of generating self-hood or abstract philosophical ideas if we think there are 100 connections between each such neuron; and we would not have the least bit more reason for thinking such a thing if we thought that there were a million connections between each such neuron. As for Aplysia, it is an animal so different from humans that experiments on it prove nothing about humans. And you don't do anything to establish that memories are stored in synapses by showing that synapses can change their state during learning. Our muscles may change their state during a particular month or week, but that does nothing to show that memories are stored in muscles.

There is an extremely strong reason for rejecting Kandel's claim that memories are stored in synapses: the fact that humans can remember things for 50 years, but the proteins in synapses are very short-lived, with an average lifetime of less than 10 days. Synapses are therefore a “shifting sands” type of thing completely unsuitable as a substrate for memories lasting a lifetime.

Kandel does his best to try to explain mental illness as being caused by brain problems. Here he is on weak ground, because in general there is little proven relation between mental illness and brain disorders. Kandel devotes 22 pages to discussing schizophrenia, trying to persuade us that it is caused by “excessive synaptic pruning.” But psychologist Paris Williams has a long post that asks, “Is Schizophrenia Really a Brain Disease?” He says, “We still have no clear evidence that schizophrenia and other psychotic orders are the result of a diseased brain.” He points out that the majority of those with schizophrenia have normal brains. He points out the inconsistency of statements by authorities on this topic, who tend in some places to say that schizophrenia is a brain disease and in other places to say that we don't know what causes schizophrenia.

Similarly, in discussing depression Kandel attempts to convince us there is a neural explanation. He states the following on page 64:

Until quite recently psychiatric difficulties were notoriously difficult to trace to particular regions of the brain. But today's brain imaging technologies, specifically PET and functional MRI, have enabled scientists to identify at least some of the components of the neural circuit responsible for depression.

Ah, “circuit” the favorite vacuous explanation word of the neuroscientist. Time and again, when asked to explain some baffling mental phenomenon, our neuroscientists will say something like, “There is a particular circuit responsible for that,” as if that was an explanation. It isn't. As for brain imaging studies, they do not provide any clear evidence that depression is caused by a brain state. An expert states, “There is no way that one could use a neuroimaging measure to decide whether a single subject is suffering from depression or not or from depression or an other mental disorder.”

Brain imaging studies can easily produce false alarms and false indicators. Let us imagine a scientist comparing the brain scans of 1000 people with depression to the brain scans of 1000 people without depression. There are 1000 different ways in which the data could be compared. But if you were able to show that comparison number 893 showed a higher score with people with depression than people without depression, that would not at all show that depression was caused by something related to comparison number 893. For it is entirely possible that such a difference would show up purely because of random variations. The way to get a more reliable indication is to look for a meta-analysis, a study that compares multiple studies to find how big an effect they found. But if you do a Google search for “meta-analysis neural correlates of depression,” you will find almost nothing along these lines. There is one meta-analysis, but it involves a total of fewer than 300 people, too few to be very reliable.

A few of the statements in the book are dubious neuroscience lore. On page 13 Kandel tries to suggest that Penfield found evidence that spontaneous memory recall could be produced by electrical brain stimulation. Read here on how a review of 80 years of such studies concluded that they provided no clear evidence that actual memories were elicited by such stimulation. On page 110 Kandel tells us that patient HM with a damaged hippocampus “lost the ability to form any new long-term memories.” But a 14-year followup study on patient HM says that long after the damage to his hippocampus (which occurred before 1960), he was shown a Kennedy half-dollar and correctly identified the person on the coin as President Kennedy, and stated that Kennedy had been assassinated. The study also says patient HM was able to learn (although very slowly) how to traverse a maze.

Kandel's subtitle suggests a strategy of studying the most unusual brains to try to get insight about ourselves. That's actually a good strategy, but Kandel doesn't really pursue it, because his book doesn't discuss any of the most interesting cases of unusual brains. These would include cases like the following:

1. The many documented cases of epilepsy patients who had half of their brains removed to stop seizures, and who mostly experienced very little decline in either intelligence or memory.
   
2. The cases examined by physician John Lorber, who documented many cases of people who had lost the great majority of their brains due to disease conditions such as hydroencephalus. Astonishingly, Lorber found that most of these patients with much less than half of their brains had above average intelligence.
   
3. Cases such as that of the Frenchman who was found to have lost 90% of his brain due to disease, who had a fairly normal intelligence, and was actively employed as a civil servant.
   
4. The very many cases of people who suffered little loss to memory or intelligence after having lots of their brain removed to treat brain cancer.
   
5. Karl Lashley's cases of animals who had large parts of their brains deliberately removed (or connections between their brains deliberately severed), but who still managed to remember mazes they had been trained on.
   
6. Cases of very old seniors with extremely good memory, despite having all of the physical “brain tangles” that are often described as a cause of Alzheimer's disease.
   
7. Some extremely interesting cases of savants who had damaged brains but who had astonishing powers of mind and memory beyond that of an average person (Kandel only gives the scantest mention of such cases, avoiding discussing in detail any of the more amazing cases).
   

Kandel has basically no discussion of any such cases, other than the slimmest mention of savant anomalies. Why doesn't he discuss such cases? I suspect that the reason is that such cases would conflict with the “brains produce minds” and “brains store memories” dogmas Kandel tries to push. So Kandel is following the current custom of so many scientists, the custom of keeping readers inside a carefully filtered information bubble, in which the reader is protected from any information that might conflict with the author's dogmas.

The book's final chapter has the revealing title, “Consciousness: The Great Remaining Mystery of the Brain.” What type of writer would create such a title, one that indicated he thought that there was only one major remaining mystery of the brain? Probably only a person who wrongly thought that he had the answers to dozens of deep mysteries of the mind and brain that have not actually been solved – a person who did not know what he did not know.  

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