Science Set Free by Rupert Sheldrake

Author:Rupert Sheldrake [Sheldrake, Rupert]
Language: eng
Format: epub
ISBN: 978-0-7704-3671-1
Publisher: Crown Publishing Group
Published: 2012-09-03T16:00:00+00:00

Currently, in the Connectome Project researchers at the Massachusetts Institute of Technology and elsewhere are trying to map some of the trillions of connections between nerve cells in mammalian brains, using thin slices of brain tissue and sophisticated computer analyses of the images. There are about 100 billion neurons in the human brain. As Sebastian Seung, the leader of the MIT team, pointed out, “In the cerebral cortex, it’s believed that one neuron is connected to 10,000 others.” This is a vastly ambitious project, but it seems unlikely to shed light on memory storage. First of all, a person has to be dead before his brain can be cut up, so changes before and after learning cannot be studied in this way. Second, there are great differences between the brains of different people; we do not have identical “wiring.”

The same is true of small animals like mice. A pilot project in the Max Planck Institute in Germany looked at the wiring diagrams for just fifteen neurons that control two small muscles in mouse ears. Even though this work was a technical tour de force, it revealed no unique wiring diagram. Even for the right and left ears of the same animal the patterns of connection were different.14

The most striking deviations from normal brain structure occur in people who suffered from hydrocephalus when they were babies. In this condition, also called “water on the brain,” much of the skull is filled with cerebrospinal fluid. The British neurologist John Lorber found that some people with extreme hydrocephalus were surprisingly normal, which led him to ask the provocative question: “Is the brain really necessary?” He scanned the brains of more than six hundred people with hydrocephalus, and found that about sixty had more than 95 percent of the cranial cavity filled with cerebrospinal fluid. Some were seriously retarded, but others were more or less normal, and some had IQs of well over 100. One young man who had an IQ of 126 and a first-class degree in mathematics, a student from Sheffield University, had “virtually no brain.” His skull was lined with a thin layer of brain cells about a millimeter thick, and the rest of the space was filled with fluid.15 Any attempt to explain his brain in terms of a standard “connectome” would be doomed to failure. His mental activity and his memory were still able to function more or less normally even though he had a brain only 5 percent of the normal size.

The available evidence shows that memories cannot be explained in terms of localized changes in synapses. Brain activity involves rhythmic patterns of electrical activity extended over thousands or millions of nerve cells, rather than simple reflex arcs like wires in a telephone exchange or wiring diagrams of computers. These patterns of nervous activity set up—and respond to—changes in the electromagnetic fields in the brain.16 The oscillating fields of entire brains are routinely measured in hospitals with electroencephalographs (EEG), and within these overall rhythms there are many subsidiary patterns of electrical activity in different regions of the brain.

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