Ignoring the voices in your head

By Casey Frye, CCNN Writer

Neurons in the motor cortex of the brain, colored in bright orange, connect to the region responsible for sound!

Our brains are constantly ignoring our own speaking voice while amplifying the sound of other people talking. This ability is not only good for listening to juicy gossip and sharing the latest drama with your pals, it’s also helpful for complex activities such as learning a language or playing an instrument.

Researchers have always speculated that the region of the brain that’s responsible for movement – like talking out loud or strumming a guitar chord – is related to the regions responsible for listening to sounds, but they could never find the link between the two. That is, until neurologists from Duke University School of Medicine found the brain pathway that allows this to happen!

According to their research, the part of the brain responsible for movement gives the region responsible for sounds a heads up that it’s going to make some noise. So, say someone wanted to move their vocal cords in order to talk. The motor center in the brains tells the area responsible for sound, “Hey, I’m about to start speaking right now, so if you hear any noise, don’t mind me, just go about your business and listen for other people!” The Duke researchers claim this communication inside the brain is important for gaining in-depth knowledge of the brain. In fact, they believe that if there is a problem with this connection, it could cause brain and mood disorders like schizophrenia that leads to people hearing voices no one else can.

“Our finding is important because it provides the blueprint for understanding how the brain communicates with itself, and how that communication can break down to cause disease,” said Richard Mooney, Ph.D., senior author of the study and professor of neurobiology at Duke University School of Medicine. “Normally, motor regions would warn auditory regions that they are making a command to speak, so be prepared for a sound. But in psychosis, you can no longer distinguish between the activity in your motor system and somebody else’s, and you think the sounds coming from within your own brain are external.”

The neurobiologists are planning to use their understanding of the connection to experiment with schizophrenic brains, and maybe even find a cure!

Featured image courtesy of Capn Madd Matt on Flickr. Image of neurons courtesy of Duke University.