Great Myths of the Brain

1Defunct Myths

The consensus used to be that the earth is flat. Combustible materials, eminent scientists once proposed, all contain the nonexistent substance phlogiston. Mars, they told us, is crisscrossed with canals. All these once-influential ideas have been consigned to the scrap heap of obsolete theories. Brain science too has its share of defunct notions. This chapter is about those brain myths that no one (or very few people) believes any more. We'll start with the ancient idea that the mind is located, not in the brain, but in the heart. As the importance of the brain was eventually accepted, other myths to emerge or persist were that the nerves are filled with animal spirits and the main mental functions are located in the fluid-filled hollows of the brain: the ventricles.

Myth #1 Thought Resides in the Heart

It seems obvious to us today that thoughts and reason are located in the brain. That's because we've grown up knowing this universally accepted fact. But from a subjective point of view, there's little, other than the position of our eyes, to tell us that our mental life is housed in our heads. So perhaps we shouldn't be too surprised that many ancient civilizations from the Greeks to the Egyptians believed that the seat of mental function was located not in the brain but in the heart.

It is not that these cultures were necessarily unaware of the functional significance of the brain. Extracts from the Edwin Smith Surgical Papyrus (bought by the American archaeologist ...