Shout now! How nerve cells initiate voluntary calls

"Should I say something or not?" Human beings are not alone in pondering this dilemma – animals also face decisions when they communicate by voice. University of Tübingen neurobiologists Dr. Steffen Hage and Professor Andreas Nieder have now demonstrated that nerve cells in the brain signal the targeted initiation of calls – forming the basis of voluntary vocal expression. Their results are published in Nature Communications.

When we speak, we use the sounds we make for a specific purpose – we intentionally say what we think, or consciously withhold information. Animals, however, usually make sounds according to what they feel at that moment. Even our closest relations among the primates make sounds as a reflex based on their mood. Now, Tübingen neuroscientists have shown that are able to call (or be silent) on command. They can instrumentalize the sounds they make in a targeted way, an important behavioral ability which we also use to put language to a purpose.

To find out how the in the brain catalyse the production of controled vocal noises, the researchers taught rhesus monkeys to call out quickly when a spot appeared on a computer screen. While the monkeys solved puzzles, measurements taken in their revealed astonishing reactions in the cells there. The became active whenever the monkey saw the spot of light which was the instruction to call out. But if the monkey simply called out spontaneously, these nerve cells were not activated. The cells therefore did not signaled for just any vocalisation – only for calls that the monkey actively decided to make.

The results published in Nature Communications provide valuable insights into the neurobiological foundations of . "We want to understand the in the brain which lead to the voluntary production of calls," says Dr. Steffen Hage of the Institute for Neurobiology, "because it played a key role in the evolution of human ability to use speech." The study offers important indicators of the function of part of the brain which in humans has developed into one of the central locations for controlling speech. "Disorders in this part of the human brain lead to severe speech disorders or even complete loss of speech in the patient," Professor Andreas Nieder explains. The results – giving insights into how the production of sound is initiated – may help us better understand speech disorders.

More information: Steffen, R., Nieder, H., and Nieder, A. Single neurons in monkey prefrontal cortex encode volitional initiation of vocalizations, Nature Communications. DOI: 10.1038/ncomms3409, 2013doi:10.1038/ncomms3409, 2013

Related Stories

Why do we gesticulate?

date Jul 02, 2013

If you rely on hand gestures to get your point across, you can thank fish for that! Scientists have found that the evolution of the control of speech and hand movements can be traced back to the same place in the brain, which ...

Recommended for you

Men and women could use different cells to process pain

date 4 hours ago

We have known for some time that there are sex differences when it comes to experiencing pain, with women showing a higher sensitivity to painful events compared to men. While we don't really understand w ...

Pupillary reflex enhanced by light inside blind spot

date 6 hours ago

University of Tokyo researchers have found that the light reflex of the pupil is modulated by light stimulation inside the blind spot in normal human observers, even though that light is not perceived.

How your brain knows it's summer

date 21 hours ago

Researchers led by Toru Takumi at the RIKEN Brain Science Institute in Japan have discovered a key mechanism underlying how animals keep track of the seasons. The study, published in Proceedings of the Na ...

His and her pain circuitry in the spinal cord

date Jun 29, 2015

New research released today in Nature Neuroscience reveals for the first time that pain is processed in male and female mice using different cells. These findings have far-reaching implications for our ba ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.