Schiller: ‘Another researcher, a postdoc, put candidates in an MRI scanner and asked them to name pictures while they were exposed to sound, so that they couldn't hear themselves speak. Here, too, we saw different areas of the brain being activated than when they could hear themselves talk. This is a first step to resolving the question of which structures are important for monitoring. I intended to apply this test to stutterers. One of the theories about people who stutter is that their internal monitoring system doesn't function properly. Their brain keeps giving signals that they have said something wrong, which means that they keep on starting over again. I haven't got around to this yet, but I still intend to carry out these tests.'