if I only had no brain

Update: A hearty welcome to readers of The Loom.


This meme shows up in the weirdest places. And I quote:

Or consider a still more striking example. The December 12, 1980, issue of Science contained an article by Roger Lewin titled “Is Your Brain Really Necessary?” In the article Lewin reported a case study by John Lorber, a British neurologist and professor at Sheffield University:

There’s a young student at this university,” says Lorber, “who has an IQ of 126, has gained a first-class honors degree in mathematics, and is socially completely normal. And yet the boy has virtually no brain.” The student’s physician at the university noticed that the youth had a slightly larger than normal head, and so referred him to Lorber, simply out of interest. “When we did a brain scan on him,” Lorber recalls, “we saw that instead of the normal 4.5-centimeter thickness of brain tissue between the ventricles and the cortical surface, there was just a thin layer of mantle measuring a millimeter or so. His cranium is filled mainly with cerebrospinal fluid.

Is it really possible for someone with nearly no brain to magically maintain cognitive function? Is this the killer dualist anecdote, proving the mind-body gap not only unbridgeable, but a complete red herring?

Skepticism is in order. John McCrone writes,

Lorber's claims were never publicly refuted. And Lorber – who died in 1996 – stuck firmly to his story, claiming that in 500 CT scans he had found many hydrocephalics with hardly any brain left above the level of the brainstem and yet living ordinary lives (Lorber, 1981). So a little detective work was needed to get to the bottom of this one.

Talking to colleagues and contemporaries of Lorber, it was revealed he was probably greatly exaggerating the extent of brain loss in his cases. Said one source: "If the cortical mantle actually had been compressed to a couple of millimetres, it wouldn't even have shown up on his X-rays." Another agreed, adding that brain scans with modern techniques such as MRI (magnetic resonance imaging) show stretching, but not much real loss of brain weight with slow-onset hydrocephalus. He says the brain structure adapts to the space it is allowed: "The cortex and its connections are still there, even if grossly distorted."

Sufferers with hydrocephalus also report many subtle symptoms that don't show up in standard tests of cognition. They do well on basic reading and arithmetic or IQ-type questions, but struggle with focused attention, spatial imagination, general motor co-ordination, and other skills that rely on longer-range integrative links across the brain. This fits a picture of a brain in which all the cortical processing regions are in place but where the white matter - the wealth of insulated connections that actually occupies much of the centre of the cerebral hemispheres - has been pulled out of shape.

So Lorber's results were striking but overplayed. And certainly the rise of neuroimaging over the past decade ought finally to have put paid to this long-running myth about the 10 percent brain. One of the most important lessons from the first scanning studies of brains actually caught in the act of thinking - with areas lighting up with increased metabolic activity – was just how widespread were the patterns of activation for the most minor mental responses. No areas were silent, just relatively active or inactive in forming the reaction to the moment.

We need our brains. It's that simple.