Cases of High Mental Function Despite Large Brain Damage

It has been known for decades that mental function can operate at a high level even though large portions of a brain are destroyed. This was proven by the memory experiments of Karl Lashley. Over many years, Lashley did extensive research in which he tested how memory and learning is affected when you take out various parts of an animal's brain. Lashley tested using three types of mazes of varying difficulty. Astonishingly, Lashley found that you could remove half of a rat's brain, and it had very little effect on the rats ability to remember either of the two simpler types of mazes.

Here are some startling results listed by Lashley:

1. Rats, trained to have a differential reaction to light, showed no reduction in accuracy of performance when the entire motor cortex of the brain, along with the frontal poles of the brain, was removed.
2. Monkeys were trained to open various latch boxes. The entire motor areas of the monkeys' brains were removed. After 8 to 12 weeks of paralysis, during which they had no access to the latch boxes, the monkeys were then able to open the boxes “promptly” and “without random exploratory movements.”
3. 13 rats were trained to solve mazes, and we read here "only one animal did not show evidence of the maze habit after removal of the frontal portions of the brain." 
4. Rats were trained to solve mazes, and the rats then had incisions made separating different parts of their brains. This produced no effect in memory retention.
5. Monkeys were trained to unlatch latch boxes.  After having their prefrontal cortex removed, there was “perfect retention of the manipulative habits.”
6. Lashley said, “A number of experiments with rats have shown that habits of visual discrimination survive the destruction of any part of the cerebral cortex except the primary visual projection area.”
   

Details on these experiments can be found online in Karl Lashley's paper, “In Search of the Engram,” and in the book here giving all of Lashley's main papers (a good that can be read online by registered users of www.archive.org). 

Recently there was published a superb scientific paper describing cases of very high mental activity despite very great brain damage.

Entitled "Discrepancy Between Cerebral Structure and Cognitive Functioning," the paper (authored by Nahm, Rousseau and Greyson, two PhD's and an MD) will be read by some who are merely interested in reading about weird curiosities. But a better way to read the paper is to examine its examples and ask: is the standard “mind from brain” dogma taught by neuroscientists (the dogma that minds are generated by brains) consistent with these examples? Together the examples seem to provide a very strong challenge to such a dogma.

On page 1 we learn of a case reported by Martel in 1823 of a boy who after age five lost all of his senses except hearing, and became bed-confined. Until death he “seemed mentally unimpaired.” But after he died, an autopsy was done which found that apart from “residues of meninges" there was "no trace of a brain" found inside the skull. How could the boy have seemed “mentally unimpaired” with almost no brain?

The paper then discusses a case examined by physician John Lorber, who studied many patients with hydrocephalus, in which healthy brain tissue is gradually replaced by a watery fluid. A mathematics student with an IQ of 130 and a verbal IQ of 140 was found to have “virtually no brain.” His vision was apparently perfect except for a refraction error, even though he had no visual cortex (the part of the brain involved in sight perception).

We are told that of about 16 patients Lorber classified as having extreme hydrocephalus (with 90% of the area inside the cranium replaced with spinal fluid), half of them had an IQ of 100 or more. The article mentions 16 patients, but the number with extreme hydrocephalus was actually 60, as this article states, using information from this original source that mentions about 10 percent of a group of 600. So the actual number of these people with tiny brains and above-average intelligence was about 30. The article states:

[Lorber] described a woman with an extreme degree of hydrocephalus showing “virtually no cerebral mantle” who had an IQ of 118, a girl aged 5 who had an IQ of 123 despite extreme hydrocephalus, a 7-year-old boy with gross hydrocephalus and an IQ of 128, another young adult with gross hydrocephalus and a verbal IQ of 144, and a nurse and an English teacher who both led normal lives despite gross hydrocephalus.

Lorber's cases date from several decades ago, but more recent cases have been reported of people with good mental functioning despite having almost all of their brains replaced by a watery fluid due to hydrocephalus. The scientific paper cites the cases below:

Another interesting case is that of a 44-year-old woman with very

gross hydrocephalus described by Masdeu (2008) and Masdeu et al.(2009). She had a global IQ of 98, worked as an administrator for a government agency, and spoke seven languages. In Leipzig, Germany, staff members of the Max Planck Institute for Human Cognitive and Brain Sciences recorded a similar case. A man was examined because of his headache, and to his physicians' surprise, he had an “incredibly large hydrocephalus.” Villinger, the director of the Cognitive Neurology Department, stated that this man had “almost no brain,” only “a very thin layer of cortical tissue.” This man led an unremarkable life, and his hydrocephalus was only discovered by chance (Hasler, 2016, p. 18)

The paper informs us of cases of people who functioned well despite losing half of their brains. We are told of a 36-year-old man whose “intellect and language abilities were unimpaired” despite the fact that the left hemisphere of his brain was “almost completely lacking.” We are told of a boy who was an average student at a regular school, even though he had a “nearly complete absence” of the right hemisphere of his brain. The paper also cites cases of people who had large portions of their brain missing, but who did not notice any problem until they had seizures or headaches. The paper states this:

For example, Baudoin (1996) described the case of a 30-year-

old woman who had a large lesion on her right cerebral hemisphere. The right occipital and parietal lobes were entirely missing, as well as the inferior part of the right temporal lobe. The brain lesion was discovered only because of the patient's first seizures at the age of 30. Similarly, Duyff et al. (1996) presented the case of a 32-year-old lawyer whose brain showed a large arachnoid cyst in the right frontotemporal region that had displaced (or replaced) the temporal lobe and parts of the frontal and parietal lobes. His development had been completely normal, and no abnormalities were discovered upon neurological examination. His condition was discovered only because he had a persistent headache after a skiing accident in which he had fallen on his head.

Hemispherectomy is a surgical procedure in which half of the brain is removed. I knew that the procedure can be performed on young children suffering from seizures, with surprisingly little negative impact. But the paper also tells us on page 3 that “Although most hemispherectomies are performed on young children, adults are also operated on with remarkable success.”
 

 Schematic diagram of a hemispherectomy

Very interestingly, we are told that when half of their brains are removed in these operations, “most patients, even adults, do not seem to lose their long-term memory such as episodic (autobiographic) memories.” The paper tells us that Dandy, Bell and Karnosh “stated that their patient's memory seemed unimpaired after hemispherectomy,” the removal of half of their brains. We are also told that Vining and others “were surprised by the apparent retention of memory after the removal of the left or the right hemisphere of their patients.”

The paper then tells the case of Kim Peek, an autistic savant who had no corpus callosum (the “bridge” connecting the two brain hemispheres). Much of Peek's brain consisted of empty areas filled with cerebrospinal fluid. But still “he memorized more than 12,000 books, apparently verbatim.”

On page 59 of the book The Biological Mind, the author states the following:

A group of surgeons at Johns Hopkins Medical School performed fifty-eight hemispherectomy operations on children over a thirty-year period. "We were awed," they wrote later of their experiences, "by the apparent retention of memory after removal of half of the brain, either half, and by the retention of the child's personality and sense of humor." 

In the paper "Neurocognitive outcome after pediatric epilepsy surgery" by Elisabeth M. S. Sherman, we have some discussion of the effects on children of temporal lobectomy (removal of the temporal lobe of the brain) and hemispherectomy, surgically removing half of their brains to stop seizures. We are told this:

After temporal lobectomy, children show few changes in verbal or nonverbal intelligence....Cognitive levels in many children do not appear to be altered significantly by hemispherectomy. Several researchers have also noted increases in the intellectual functioning of some children following this procedure....Explanations for the lack of decline in intellectual function following hemispherectomy have not been well elucidated. 

Referring to a study by Gilliam, the paper states that of 21 children who had parts of their brains removed to treat epilepsy, including 10 who had surgery to remove part of the frontal lobe, "none of the patients with extra-temporal resections had reductions in IQ post-operatively," and that two of the children with frontal lobe resections had "an increase in IQ greater than 10 points following surgery." 

The paper here gives precise before and after IQ scores for more than 50 children who had half of their brains removed in a hemispherectomy operation in the United States.  For one set of 31 patients, the IQ went down by an average of only 5 points. For another set of 15 patients, the IQ went down less than 1 point. For another set of 7 patients the IQ went up by 6 points. 

The paper here (in Figure 4) describes IQ outcomes for 41 children who had half of their brains removed in hemispherectomy operations in Freiburg, Germany. For the vast majority of children, the IQ was about the same after the operation. The number of children who had increased IQs after the operation was greater than the number who had decreased IQs. 

It also should be remembered that brain-damaged patients taking standard IQ tests may have higher intelligence than the test score suggests.  A standard IQ test requires visual perception skill (to read the test book) and finger coordination (to fill in the right answers using a pencil). Brain damage might cause reduced finger coordination and reduced visual perception unrelated to intelligence; and such things might cause a subject to do below-average on a standard IQ test even if his intelligence is normal. 

At this URL there was recently published a case of a man with a 9-centimeter (3 inch) wide "air-filled cavity" in the right frontal lobe of his brain.

Although the paper is entitled "The man that lost (part of) his mind," the paper indicates no sign of mental damage:

An 84-year-old man was referred to the emergency department by his general practitioner having been complaining of recurrent falls and feeling unsteady over several months. He then developed a 3-day history of left-sided arm and leg weakness. There was no confusion, facial weakness, visual or speech disturbance, and he was feeling otherwise well.

The man showed good judgment in declining a risky operation that wasn't vitally necessary. But how could someone have so little damage from a giant hole in a part of the brain that supposedly is involved in language, memory, and judgment? Cases like these are inconsistent with dogmas about minds being generated by brains.

Now for another similar anomaly that is even more amazing. This is a case in which a human managed to function well in society as a French civil servant, even though he had almost no functional brain. The case is discussed here in a story entitled “Man lives normal life with abnormal brain”:

Inside a normal brain are tiny structures called lateral ventricles that hold brain fluid. In this man's case, the ventricles had swollen up like balloons, until they filled almost all of the man's brain. When the 44-year-old man was a child, doctor's had noticed the swelling, and had tried to treat it. Apparently the swelling had progressed since childhood. The man was left with what the Reuters story calls “little more than a sheet of actual brain tissue.”

But this same man, with almost no functioning brain, had been working as a French civil servant, and had his IQ tested to be 75, higher than that of a mentally retarded person. The Reuters story says: “A man with an unusually tiny brain managed to live an entirely normal life despite his condition, caused by a fluid buildup in his skull.” The case was written up in the British medical journal The Lancet in a paper entitled “Brain of a white-collar worker.”

In a later "ScienceAlert" story on this case, a cognitive psychologist states, "Any theory of consciousness has to be able to explain why a person like that, who's missing 90 percent of his neurons, still exhibits normal behavior." 

90 percent of his neurons lost, and normal behavior -- that's radically inconsistent with the "brains make minds" dogma.

In the medical paper “Revisiting Hydrocephalus as a Model to Study Brain Resilience” by de Oliviera and Pinto, we are shown a photo of a patient with almost no brain, because he had hydrocephalus that has replaced almost all of his brain tissue with a watery fluid. But the patient is described in the paper as “normal,” and is contrasted with another patient with a similar condition who had cognitive problems. Apparently this “normal” patient suffered few cognitive effects from having lost almost all of his brain. The paper is at the URL here.

At the URL here you can find a book chapter entitled, “Memory

consolidation, retrograde amnesia, and the temporal lobe.” Tables 4 and 5 of this paper give us detailed information on 16 cases of severe brain damage documented in the medical literature. The patients had damage in between three and ten different parts of their brain, with an average of about four or five different brain areas being damaged. The tables give IQ scores for these 16 patients, and the average score was 99 – just one point less than 100, the average IQ. But how could their average intelligence be so normal, if they had such heavy brain damage?

As discussed here, years ago a man named Pat Martino had an operation in which 70 percent of his left temporal lobe was removed. But today he plays virtuoso jazz guitar flawlessly, and you can see his impressive performances and instructional guitar videos on youtube.com, made after his operation. You would never guess there was any problem in his brain.

In his essay “A Map of the Soul,” neuroscientist Michael Egnor states the following:

I have scores of patients who are missing large areas of their brains, yet who have quite good minds. I have a patient born with two-thirds of her brain absent. She’s a normal junior high kid who loves to play soccer. Another patient, missing a similar amount of brain tissue, is an accomplished musician with a master’s degree in English.

The same author tells us here that the patient with two-thirds of her brain absent made the honor roll at school. The paper "Neuropsychological and neurophysiological evaluation of cognitive deficits related to the severity of traumatic brain injury" studied the IQ of 90 patients, dividing them into three categories: mild traumatic brain injury, moderate traumatic brain injury, and severe traumatic brain injury. The mean IQ in each of these groups was about the same, being either 103 or 104. We read that "a surprising finding was that specific intelligence subtests did not show [sensitvity] even for differentiation between severe and mild injury." Such a result is surprising only to those who think your brain makes your mind, not those who reject such an idea.

It is often claimed that certain mental capabilities such as intelligence come from a part of the brain called the prefrontal cortex. But the authors of a scientific paper say “we have studied numerous patients with bilateral lesions of the ventromedial prefrontal (VM) cortex” and that “most of these patients retain normal intellect, memory and problem-solving ability in laboratory settings.”  On page 342 of the book Developmental Neuropsychology we read the following about brain surgery on children: "Removal of benign astrocytic and oligodendrocytic tumors in one of the cortical hemispheres had little effect on personality and intelligence; 72 percent of 42 consecutive cases had no problems in school on follow-up (Hirsch et al. 1989)."

Such cases are powerful evidence against the dogma that our minds are merely a product of our brains. Repeated countless times in mainstream literature, but never proven, such a dogma is also discredited by both the inability of neuroscience to plausibly account for consciousness and very-long-term human memory, and the inability of a "mind from brain" dogma to account for psychic phenomena such as ESP, remote viewing, and near-death experiences. Nature never told us that minds come from brains. It was merely neuroscientists who told us that, without having sufficient evidence to support such a claim. Don't confuse such ideologically-motivated scientist speech customs with facts.

Alternatives to the "mind from brain" dogma include the idea of a human soul and the idea that human consciousness may have some mysterious consciousness infrastructure as its source, possibly something cosmic in scope. When asked "Where do your smartphone games come from," a child may answer with great certainty, "From the smartphone, of course." But such games may actually come from some mysterious information infrastructure involving the Internet and remote servers, something the child knows nothing about. Similarly, our minds may have as their main source some mysterious non-biological consciousness infrastructure we know nothing about.

In this post I have merely listed some of the very many cases showing high mental function despite large brain damage. See this post for many more such cases.  

Postscript:  In the paper "Does brain tumor histology influence cognitive function?" Anne E. Kayl and Christina A. Meyers give us a study of dozens of patients who had very severe brain tumors. Noting a lack of any relation between the size of the brain tumors and mental function (contrary to what you would expect from "brains make minds" dogma), they state this:

"Statistical analyses failed to detect a significant effect of tumor histology or tumor volume on intellectual, memory, language, executive, or motor function. In fact, regression and correlation analyses suggest that patient age is of greater importance than tumor histology or tumor volume for determining neuropsychological test performance. Tumor volume was neither predictive of, nor reliably associated with cognitive performance in this patient sample. While these results affirm age as a marker for a worsened prognosis for the more advanced forms of anaplastic glioma, the statistically nonsignificant relationship of tumor volume to cognitive function was unexpected."

Below is a very notable case of the almost complete destruction of a brain by a brain tumor, but with a high preservation of mental function. It comes from page 71 of the document here (and the newspaper story here repeats the same details).