More than twenty years ago, a team of scientists discovered special brain cells, called mirror neurons - cells in the brain that fire not only when we perform a particular action but also when we watch someone else perform that same action - in monkeys.
Since then there has been an intense debate as to whether the mirror neuron system is involved in such diverse processes as understanding speech, understanding the meaning of other people's actions, and understanding other people's minds.
Now, a new study has suggested that the mirror neuron system plays some role in how we understand other people's speech, but it's likely that this role is much smaller than has been previously claimed.
In fact, the role is small enough that it's unlikely that mirror neurons would be causal factors in our ability to understand speech.
Mirror neuron-related processes may only contribute to understanding what another person is trying to say if the room is very noisy or there are other complications to normal speech perception conditions.
One of the most powerful roles suggested for the mirror neuron system in humans is that of understanding not just other people's physical actions or speech, but their minds and their intentions.
It has also been suggested that some persons, such as persons with autism, have difficulty understanding other people's minds and, therefore, might lack mirror neurons.
The study has been published in Perspectives on Psychological Science.