“
One unexpected hint comes from patients with a strange disorder called anosognosia, a condition in which people seem unaware of or deny their disability. Most patients with a right-hemisphere stroke have complete paralysis of the left side of their body and, as you might expect, complain about it. But about one in twenty of them will vehemently deny their paralysis even though they are mentally otherwise lucid and intelligent. For example, President Woodrow Wilson, whose left side was paralyzed by a stroke in 1919, insisted that he was perfectly fine. Despite the clouding of his thought processes and against all advice, he remained in office, making elaborate travel plans and major decisions pertaining to American involvement in the League of Nations. In 1996 some colleagues and I made our own little investigation of anosognosia and noticed something new and amazing: Some of these patients not only denied their own paralysis, but also denied the paralysis of another patient—and let me assure you, the second patient’s inability to move was as clear as day. Denying one’s own paralysis is odd enough, but why deny another patient’s paralysis? We suggest that this bizarre observation is best understood in terms of damage to Rizzolatti’s mirror neurons. It’s as if anytime you want to make a judgment about someone else’s movements, you have to run a virtual-reality simulation of the corresponding movements in your own brain. And without mirror neurons you cannot do this.
”
”
V.S. Ramachandran (The Tell-Tale Brain: A Neuroscientist's Quest for What Makes Us Human)