Abstract
Interactions in electromyographic activity of the upper and lower lips during speech were studied by manipulating the magnitude of bursts of activity related to bilabial closure. Four pairs of electrodes were placed in the labial musculature in each of four normal‐speaking young adults. Activity from both the upper and the lower lip was manipulated with the jaw free and then the procedures were repeated with the jaw fixed with a bite block. Manipulation of muscle activity usually resulted in positively correlated changes in activity recorded from the other three electrode pairs. Contrary to expectations, no significant negative correlations were found. The positive correlations may be due to (a) sensitivity of the electrode placements to the same motor units, (b) sensitivity of the electrode placements to motor units participating in common recruitment orders, or (c) functional interactions among muscles or muscle compartments that constrain them to maintain task‐specific proportional relations. [Work supported by NINCDS.]
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
