The Tell-Tale Brain: A Neuroscientist’s Quest for What Makes Us Human
by V. S. Ramachandran. W. W. Norton, 2011
While giving a lecture at a hospital in Chennai, India, Vilayanur S. Ramachandran met a young man with a strange problem.
“What brings you to our hospital?” asked Ramachandran, a professor of psychology and neuroscience at the University of California, San Diego.
“I am a corpse—I can smell the stench of rotting flesh,” the young man replied.
“Are you saying you are dead?” Ramachandran pressed.
“Yes. I don’t exist,” the man confirmed.
After performing an EEG—which measures and records the electrical activity of the brain—Ramachandran concluded the man must be suffering from Cotard syndrome or “walking corpse syndrome,” a rare neuropsychiatric disorder in which people hold the delusional belief that they are dead.
Cotard syndrome is one of many unusual mental afflictions Ramachandran discusses in his new book, The Tell-Tale Brain. He also looks at Capgras syndrome (when a person believes those around him have been replaced by imposters), apraxia (when a person cannot mimic simple gestures), and telephone syndrome (when a person is comatose but can somehow converse on the phone).
Gleaning insights from these rare and intriguing neurological disorders, Ramachandran reveals how the human brain has evolved unique functions that separate us from other primates. He proposes that around 150,000 years ago our brain started to change, allowing us to learn to perform new tasks. “All the same old parts were there,” he writes, “but they started working together in ways that were far more than the sum of their parts,” giving humans distinctive traits, such as language, empathy and morality.
Take mirror neurons, nerve cells that are activated when we perform an action or when we observe someone else performing an action. These neurons appear to help animals and humans imitate the behaviors they observe. Ramachandran theorizes that this sophisticated system of mirror neurons not only evolved to create awareness of others but also brought about self-awareness in humans. He fittingly dubbed these neurons “empathy neurons.” Based on this theory, he suggests that Cotard syndrome may result from damage to mirror neuron circuits, causing a person to lose that self-awareness.
Such bold leaps may make some scientists uneasy, but they are also what make Ramachandran so provocative and his book such an entertaining read.