Someone’s asked you a question, and halfway through it, you already know the answer. While you think you’re politely waiting for your chance to respond, new research shows that you’re actually more impatient than you realize.
In the vocal equivalent of sitting on the edge of your seat, speakers position their vocal organs (tongues, jaw, lips) for the sounds they’re planning to produce in the near future, rather than passively waiting for their turn to speak.
The path to this discovery required real-time magnetic resonance imaging (MRI) of the vocal tract, which is not an easy technique. The researchers worked with graduate student engineers who helped develop algorithms to process data and extract useful images from MRI data.
The structural MRI’s took images of tissue in the vocal tract, much like an X-ray, very quickly—about 200 times a second—providing high “temporal resolution” of what was happening as subjects moved their tongues and jaw. This allowed the researchers to measure rapid changes in the positions of vocal organs before, during, and after the subjects spoke.
“It surprised us how some speakers positioned their vocal tracts to anticipate upcoming responses,” says lead researcher Sam Tilsen, “but also that there was a great variation in which vocal organs speakers used for this positioning. People don’t all behave in a unified, coherent way.”
Questions remain, says Tilsen, assistant professor of linguistics at Cornell University. Why do some people anticipate vocal responses while others do not? Why do people use different vocal organs to anticipate different sounds? Using a structural MRI limits researchers to studying movements and other behavior to understand the relation between cognition and speech, says Tilsen. His goal is to overcome that limitation through neurotechnology.
“We want to develop the ability to simultaneously record brain signals and anatomical detail,” says Tilsen, “which could involve simultaneous MRI and fMRI scanning. It’s possible, but it’s challenging.”
