- May 11th, 2020, 5:53 pm
#357711
The Rolls quote below contains a reference to a paper published by Lorber:
* Lorber, John. "Is your brain really necessary?" Nursing Mirror 152 (1981): 29–30.
However, strangely, Lorber's two-page paper was published one year after Lewin's three-page report:
* Lewin, Roger. "Is your brain really necessary?" Science 210/4475 (1980): 1232-1234.
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"A major obstacle in this work is the difficulty of obtaining the kind of quantitative data that would be expected in a scientific investigation of, say, rat brains. "I can't say whether the mathematics student has a brain weighing 50 grams or 150 grams, but it's clear that it is nowhere near the normal 1.5 kilograms," asserts Lorber, "and much of the brain he does have is in the more primitIve deep structures that are relatively spared in hydrocephalus."
Lorber concludes from these observations that "there must be a tremendous amount of redundancy or spare capacity in the brain, just as there is with kidney and liver." He also contends that "the cortex probably is responsible for a great deal less than most people imagine."
(Lewin 1980, pp. 1232-3)
"As to the question "Is your brain really necessary?" Lorber admits that it is only half serious. "You have to be dramatic in order to make people listen," concedes the tactician. Bower's answer to the tongue-in-cheek question is this: "Although Lorber's work doesn't demonstrate that we don't need a brain, it does show that the brain can work in conditions we would have thought impossible." Bower occasionally complains that Lorber's style is less scientific than it might be. He concedes, however, that "there are still many questions to be answered about the human brain, and it has to be admitted that Lorber's provocative approach does make you think about them.""
(Lewin 1980, p. 1234)
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"The man with no brain?
Prof John Lorber looked at the brain scan of the student in front of him. The student was studying for a Maths degree and had a recorded IQ of 126 (100 is the average). The student had been referred to Lorber by the university campus doctor who noticed that his head was slightly larger than normal. Knowing Lorber’s research interests into hydrocephalus he thought that the student might be worthy of further investigation. The brain scan showed that the student had practically no brain at all. It was estimated that his brain would have weighed no more than 150 grams, the normal size for a man of his age would be 10 times this at 1.5 kilograms. This, combined with further very rare cases, led Lorber and others to pose the question ‘Is your brain really necessary?’ (1981). Such evidence has questioned our understanding of the workings of the human brain and been cited as evidence to perpetuate the widely held belief that we only use 10 per cent of our brains."
(p. 268)
"John Lorber, a paediatrician and acknowledged expert on Spina Bifida was thrust into this debate after examining a patient referred to him by a GP working on the campus of Sheffield University. Lorber was a surgeon who specialised in the treatment of hydrocephalus. Hydrocephalus comes from the Greek ]hydro, meaning ‘water’, and ‘cephalus’, which means ‘head’. Hydrocephalus involves an abnormally large accumulation of cerebrospinal fluid (CSF) within the cavities (ventricles) inside the brain. If the CSF is not absorbed quickly enough, it builds up pressure in the ventricles and this causes the cerebral cortex to be crushed outwards against the skull. Lorber was performing surgery on people with hydrocephalus by inserting valves called ‘shunts’ in order to relieve the pressure caused by the build-up of CSF (Lorber, 1981). Lorber was surprised by a few patients who seemed to have little or no mental deficits but whose brain scans showed extremely enlarged ventricles, such that there was virtually no discernible cerebral cortex at all. His best known case involved a maths undergraduate with an IQ of 126 and who subsequently went on to gain a first class honours degree. Lorber claimed that his cerebral cortex on the scan was a mere millimetre or so thick (crushed by the effects of hydrocephalus) compared to the usual four or five centimetres. Lorber reckoned that his whole brain weighed a mere 150 grams compared to the typical 1.5 kilograms. Lorber subsequently published a paper with the provocative title of ‘Is your brain really necessary?’ questioning the need for areas of the cerebral cortex. On a subsequent television documentary he stated: ‘My hunch is that we all have a substantial reserve of neurons and brain cells . . . that we don’t need and don’t use’ (Beyerstein, 1998). Lorber claimed to have documented about 600 such cases and categorised them into four groups. There were:
(1) those cases with near normal brains;
(2) those with 50–70 per cent normal function;
(3) those with 70–90 per cent normal function; and
(4) those with 95 per cent of the cranium filled with CSF.
There were only about 60 cases of this last group and approximately half of these were profoundly retarded. The other half, which included the aforementioned maths graduate, had IQs above 100. In the past, in children where the skull had not yet calcified, the cranium would often balloon outwards due to the internal pressure. Before the modern technique of a shunt was used, such an affliction was likely to lead to death. So do such case studies suggest that much of the cerebral cortex is redundant or are there alternative explanations?
Conflicting evidence
The first point to be made is that in many of these cases there may have been some exaggeration of the extent of brain loss. Lorber used a CAT (computerized axial tomography) scan technique to view the internal structure of the brain. This is an x-ray procedure that, when combined with a computer, can generate cross-sectional views of the internal organs and structures of the body. It is suggested that a cerebral cortex of only a millimetre or so thick would probably not have shown up clearly on such a scan, suggesting that, in reality, the cortex might have been somewhat larger. Lorber conceded that the reading of CAT scans is difficult but remained convinced that his interpretation of the evidence was correct. More advanced brain scanning techniques have shown that the cerebral cortex is not ‘lost’ or destroyed but compacted into the smaller space available. If anything, this demonstrates the remarkable ability of the brain to adapt to circumstances. This is also supported by studies of neural damage in infants. It is well documented that children can more readily adapt to serious head injuries than adults because of the plasticity and adaptability of the human brain. There are cases of children who have one brain hemisphere surgically removed who have regained, after a period of some adjustment, most of their former abilities including language. This suggests that the remaining areas of the brain have taken over the functions of the removed hemisphere. This ‘crowding’ procedure may have also occurred with the maths graduate case study reported by Lorber.
There have also been question marks over the lack of deficit reported in some of Lorber’s patients, most notably, the maths graduate. Some of the effects of hydrocephalus are quite subtle and are not readily detectable on standard cognition tests such as IQ.
How necessary is our brain?
Despite the Lorber case study, it appears that the cerebral cortex is essential. There are well-documented cases of people suffering extreme cognitive deficits after fairly minor neurological damage. If much of our grey matter was redundant then it would be expected that people could cope quite easily after such brain trauma. In addition, it seems unlikely that natural selection would have resulted in an organ that consumes so much energy for so little return. Other costs of having a large brain (and subsequent large head) concern the greater likelihood of dangerous complications during childbirth. A smaller, more efficient brain that could cope with the same cognitive functions would surely have been advantageous and therefore naturally selected. The fact that we do have a large brain suggests some sort of selective advantage. Redundancy is fine if there are no costs but here the costs of a large brain seem to outweigh the benefits of a small, but more efficient brain.
Modern brain scanning techniques have also shown how much of the brain is used in different activities. They demonstrate that large areas of the brain are used in almost all activities. Even during sleep, that seemingly most passive of activities, the brain is surprisingly active particularly when dreaming. So much so that dream sleep is often referred to as ‘active sleep’.
Before his death in 1996, Lorber, who had a reputation for being deliberately controversial, conceded that he had perhaps over dramatised his evidence, arguing that this needed to be done in order to get people to listen. He believed that far too often results that don’t fit existing explanations are marginalised as ‘anomalous’ results (Lewin, 1980). Lorber continued to argue that there must be some redundancy or spare capacity in the brain in much the same way that there is in the kidney or liver. There is some further experimental evidence from trials on rats to support Lorber’s claims. Rats who have large areas of the cerebral cortex removed in one go seem to suffer from gross dysfunction, but rats who have the same amount of cortex removed in a series of stages can cope remarkably well and show little sign of impairment. This appears to mirror the gradual step-by-step effects of hydrocephalus seen in some of Lorber’s patients. To this day, the idea of spare capacity in the brain remains a controversial and contentious argument, but it seems most likely that reallocation of function is possible, particularly in the developing child’s brain.
Given the evidence, it is certain that the cerebral cortex is necessary and that the claim that we only use 10 per cent of our brain is nothing more than a myth or ‘urban legend’. We can be fairly certain that we use our entire brain all the time. The Lorber case study provides a fascinating peek into the workings of the brain, but rather than providing evidence of its redundancy it provides further evidence of its amazing adaptability and complexity. A complexity that we are only just beginning to comprehend."
(pp. 270-4)
(Rolls, Geoff. Classic Case Studies in Psychology. 3rd ed. London: Routledge, 2015.)
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"We may philosophize well or ill, but we must philosophize." – Wilfrid Sellars
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