Stretching Your Mouth Affects What You Hear

In my chapter INSIDE THE BRAIN I explain how the operation of certain mirror neurons in turning perception of speech in others into your own speech production was, in effect, a demonstration of the so-called motor theory of speech. Here, in this Scientific American piece, is a fascinating bit of support for this theory from David Ostry, a neuroscientist from McGill University, Montreal. Ostry used a robotic device to pull and tug areas around the mouth when volunteers synchronously heard speech sounds. So, for instance, when the volunteer heard a speech sound that could have been "head" or had" he was more likely to interpret that sound as "head" if his mouth was stretched upwards slightly toward the position he would use if he were saying the word "head". Ostry's work not only supports the idea that we use mirror neurons to learn how to speak by monitoring others' speech and reproducing those sounds for ourselves, it supports the idea that speech and language and speech production use the same motor circuits in the brain. This might help us to understand why the speech impediments in the KE family, which I report in Chapter 2 of NOT A CHIMP, are also associated with certain grammar deficits.