He applied the “Page 99 Test” to his new book on mirror neurons, Mirroring People: The New Science of How We Connect with Others (Farrar, Straus, & Giroux, 2008), and reported the following:
On page 99, the book tells the story of the deaf children in Nicaragua. They spontaneously developed a sign language under rather extraordinary circumstances. The children were socially isolated and communicated with few friends and family using simple gestures or a rudimentary, home-made language of signs. The Sandinista revolution opened two special schools in Managua for these deaf children. By doing so, the Sandinistas triggered a real-life experiment of sort. There were hundreds of children enrolled in the schools and they had many opportunities to interact socially, in the classrooms, in the school yard, and on the buses used for transportation. At the beginning, each child used her or his own simple sign language to communicate with other children. Progressively, these simpler languages of signs merged in a more complex system of signs. Eventually, the signs of the deaf Nicaraguan children became more sophisticated, a full blown spontaneously developed sign language. Ironically, the adults that were working at the school did not understand what was going on: the children were signing to each other in a complex, mysterious way, but since nobody had taught them those signs, the school staff was at a loss: what was all that signing about? After some time, with the help of linguists specialized in sign language, they realized that the children had invented a new sign language.Read an excerpt from Mirroring People, and learn more about the book at the publisher's website.
The page 99 test reveals one of the many aspects of the research on mirror neurons. These brain cells are especially famous because they enable empathy, reading the minds of other people, and help us connect with others. However, they are also implicated in the evolution of language, and they seem especially important in those aspects of language that have to do with gestures and signs.
But how do mirror neurons do all this? These cells are located in the regions of the brain that control our movements. They obviously become active when we make actions, when we grasp a cup of coffee and bring it to the mouth, when we reach for a pen to jot down a short note to ourselves. Amazingly, mirror neurons become also active when we are completely still, and we are simply watching those same actions performed by other people. By watching the actions of others, we see ourselves as reflected by a mirror. With mirror neurons, we simulate in our own brain what is going on in the brain of others. These cells help us understanding the mental states of other people, which is something we do naturally and effortlessly every day, many times. We take it for granted, but it is indeed an extraordinary feat. Mirror neurons also help us understanding all the gestures we make when we speak and when we see (and hear) other people gesturing and speaking. Those gestures seem so intrinsically tied to language that we make them even when we speak on the phone, or to blind people.
The page 99 test captures a fundamental aspect of the book, the association between gestures and language that is enabled by mirror neurons. However, it also misses several other important aspects of the research on mirror neurons, from imitation to empathy, from developing a sense of self to autism, which may be due to a dysfunction of mirror neurons. Not to worry though: they are all discussed in the rest of the book.