Mu-rhythm in the brain: The neural mechanism of speech as an audio-vocal perception-action system

December 5th, 2012 in Neuroscience /
Mu-rhythm in the brain: The neural mechanism of speech as an audio-vocal perception-action system

The cortical mechanisms governing speech are not well understood because it is extremely challenging to measure the activity of the brain in action, that is, during speech production. Researchers in Japan have found modulation of mu-rhythms in the cortex related to speech production.

Speech production is one of the most important components in human communication. However, the cortical mechanisms governing speech are not well understood because it is extremely challenging to measure the activity of the brain in action, that is, during speech production.

Now, Takeshi Tamura and Michiteru Kitazaki at Toyohashi University of Technology, Atsuko Gunji and her colleagues at National Institute of Mental Health, Hiroshige Takeichi at RIKEN, and Hiroaki Shigemasu at Kochi University of Technology have found modulation of mu-rhythms in the cortex related to speech production.

Mu-rhythm in the brain: The neural mechanism of speech as an audio-vocal perception-action system
Credit: Michiteru Kitazaki

The researchers measured EEG (electroencephalogram) with pre-amplified electrodes during simulated , simulated vocalization with delayed auditory feedback, simulated vocalization under loud noise, and . The authors define 'mu-rhythm' as a decrease of power in 8-16Hz EEG during the task period.

The mu-rhythm at the sensory-motor cortical area was not only observed under all simulated vocalization conditions, but was also found to be boosted by the delayed feedback and attenuated by loud noises. Since these auditory interferences influence speech production, it supports the premise that audio-vocal monitoring systems play an important role in speech production. The motor-related mu-rhythm is a critical index to clarify of as an audio-vocal perception-action system.

In the future, a neurofeedback method based on monitoring mu-rhythm at the sensory- may facilitate rehabilitation of speech-related deficits.

Provided by Toyohashi University of Technology

"Mu-rhythm in the brain: The neural mechanism of speech as an audio-vocal perception-action system." December 5th, 2012. http://medicalxpress.com/news/2012-12-mu-rhythm-brain-neural-mechanism-speech.html