14 DAY TRIAL // Why do you associate a "changed" voice in your partner in a possible sex party?
Not to mention you recognize him/her or your buddy without seeing them?
A new research indicates that when we pass through a new situation with associated sounds, the brain quickly makes connections between regions responsible for performing the action and those linked with the sound.
"The findings may contribute to understanding how we acquire language and how we think of actions if we only hear their sounds," said authors Amir Lahav, ScD, and Dr. Gottfried Schlaug, MD, of the neurology department at Beth Israel Deaconess Medical Center and Harvard Medical School.
"The findings have implications for understanding many complex processes, such as speech and music performance and they could encourage research into rehabilitative strategies using sound-movement tasks", said Dr. Robert Zatorre, head of the auditory cognitive neuroscience laboratory at McGill University.
The new discoveries also enhance the hypothesis about the existence of a mirror neuron system in the human brain. Mirror neurons were found in monkeys and are activated not only when the monkey performs an action, but also when it watches the same action realized by others or only hears the sound associated with the action.
In their experiment, the scientists taught nine volunteers with no previous musical training to play a five-note, 24-second song on a keyboard. After that, the subjects were put to listen to the song they had just learned, a different song using the same five notes, and a third song made up of additional notes. Functional magnetic resonance imaging (fMRI) scanning revealed that the familiar music induced activation in brain areas in the frontal and parietal lobes involved in locomotion control.
Broca's area, which in monkeys harbors the mirror neurons, was the most active when subjects listened to music they knew how to play compared to other music. "Mirror-neuron circuits appear to encode and reflect templates for specific actions," the authors say.
"This may allow us to comprehend motor acts when they are observed or heard, without the need for explicit reasoning about them."
The sound-related functions of a mirror-neuron system "might have developed for survival reasons, allowing us to understand actions even when they cannot be observed, but can only be heard, as when we hear footsteps in the dark."