Is the Brain Really Necessary?

(Or What and Where Is Consciousness)

This was the question asked by British neurologist John Lorber when

he addressed a conference of pediatricians in 1980. Such a

frivolous sounding question was sparked by case studies Lorber had

been involved in since the mid sixties.

The case studies involve victims of an ailment known as

hydrocephalus, more commonly known as water on the brain. The

condition results from an abnormal build up of cerebrospinal fluid

and can cause severe retardation and death if not treated.

Two young children with hydrocephalus referred to Lorber presented

with normal mental development for their age. In both children,

there was no evidence of a cerebral cortex. One of the children

died at age three months, the second at twelve months was still

following a normal development profile with the exception of the

apparent lack of cerebral tissue shown by repeated medical testing.

An account of the children was published in Developmental Medicine

and Child Neurology.

Later, a colleague at Sheffield University became aware of a young

man with a larger than normal head. He was referred to Lorber even

though it had not caused him any difficulty. Although the boy had

an IQ of 126 and had a first class honors degree in mathematics, he

had “virtually no brain”.

A noninvasive measurement of radio density known as CAT scan showed

the boy’s skull was lined with a thin layer of brain cells to a

millimeter in thickness. The rest of his skull was filled with

cerebrospinal fluid. The young man continues a normal life with the

exception of his knowledge that he has no brain.

Although anecdotal accounts may be found in medical literature,

Lorber is the first to provide a systematic study of such cases. He

has documented over 600 scans of people with hydrocephalus and has

broken them into four groups:

those with nearly normal brains.

those with 50-70% of the cranium filled with CSF

those with 70-90% of the cranium filled with CSF

and the most severe group with 95% of the cranial cavity

filled with cerebrospinal fluid.

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Of the last group, which comprised less than ten percent of the

study, half were profoundly retarded. The remaining half had IQs

greater than 100.

Skeptics have claimed that it was an error of interpretation of the

scans themselves. Lorber himself admits that reading a CAT scan can

be tricky. He also has said that one would not make such a claim

without evidence.

In answer to attacks that he has not precisely quantified the amount

of brain tissue missing, he adds, “I can’t say whether the

mathematics student has a brain weighing 50 grams or 150 grams, but

it is clear that it is nowhere near the normal 1.5 kilograms.”

Many neurologists feel that this is a tribute to the brains

redundancy and it’s ability to reassign functions. Others, however,

are not so sure. Patrick Wall, professor of anatomy at University

College, London states “To talk of redundancy is a copout to get

around something you don’t understand.”

Norman Geschwind, a neurologist at Bostons Beth Israel Hospital

agrees: “Certainly the brain has a remarkable capacity for

reassigning functions following trauma, but you can usually pick up

some kind of deficit with the right tests, even after apparently

full recovery.”

Anthony Smith “The Mind” New York

Viking Press, 1984, p.230

Roger Lewin “Is Your Brain Really Necessary?”

Science 210 December 1980, p. 1232