'Miming' brain helps humans to learn how to speak
RESEARCHERS have discovered that parts of the brain that are involved in controlling our mouths when we speak are also activated when we listen.
The findings are now helping to shed light on how young children learn to speak and why humans have evolved complex speech while other animals have not.
Dr Joe Devlin, from the division of psychology and language sciences at University College London, said: “There is a really critical interaction between the parts of the brain processing sound and those parts that are used to produce the same sound.
“Even though they are centimetres apart from each other there is obviously communication going on between those brain cells.
“That kind of thing is critical for any kind of verbal learning and is important for how children learn to speak and requires those interactions.
“However, chimps or many songbirds learn their speech almost intrinsically without listening to others.”
Using a technique known as transcranial magnetic stimulation, Dr Devlin and his team have been able to explore how the brain reacts when listening to speech.
This uses a strong magnetic pulse to increase the activity of the brain cells involved in controlling the mouth muscles when speaking, helping to amplify any signals they produce.
They found that when listening to speech from a programme on Radio 4, these muscle were far more active compared to when listening to white noise.
Dr Devlin said: “This is an indication that the motor part of the brain is involved even though I was just sitting passively listening.
“The question becomes what is it doing, why does it help and what are the limits and that is the research we are now doing.
“Our hypothesis is that the wiring patterns in our brains have changed a little bit over the seven million years since we diverged from our ape cousins.
“That can have big implications as different parts of the brain start interacting in new ways and that allows us to do new things.
“Animals do not have the subtleties that are critical to recognise the differences between two words, so it is possible this interaction with the motor part of the brain may be the reason why.”