Somatosensory Gating Is Dependent on the Rate of Force Recruitment in the Human Orofacial System PurposeFunctional orofacial behaviors vary in their force endpoint and rate of recruitment. This study assessed the gating of orofacial cutaneous somatosensation during different cyclic lip force recruitment rates. Understanding how differences in the rate of force recruitment influences trigeminal system function is an important step toward furthering the knowledge of ... Article
Article  |   December 01, 2009
Somatosensory Gating Is Dependent on the Rate of Force Recruitment in the Human Orofacial System
 
Author Notes
  • Contact author: Richard D. Andreatta, Department of Rehabilitation Sciences, Divison of Communication Sciences and Disorders, University of Kentucky, 900 South Limestone Street, Wethington 120-F, Lexington, KY 40536. E-mail: richard.andreatta@uky.edu.
Article Information
Research Issues, Methods & Evidence-Based Practice / Speech
Article   |   December 01, 2009
Somatosensory Gating Is Dependent on the Rate of Force Recruitment in the Human Orofacial System
Journal of Speech, Language, and Hearing Research, December 2009, Vol. 52, 1566-1578. doi:10.1044/1092-4388(2009/08-0116)
History: Received June 4, 2008 , Accepted February 6, 2009
 
Journal of Speech, Language, and Hearing Research, December 2009, Vol. 52, 1566-1578. doi:10.1044/1092-4388(2009/08-0116)
History: Received June 4, 2008; Accepted February 6, 2009
Web of Science® Times Cited: 4

PurposeFunctional orofacial behaviors vary in their force endpoint and rate of recruitment. This study assessed the gating of orofacial cutaneous somatosensation during different cyclic lip force recruitment rates. Understanding how differences in the rate of force recruitment influences trigeminal system function is an important step toward furthering the knowledge of orofacial sensorimotor control.

MethodLower lip vibrotactile detection thresholds (LL-VDTs) were sampled in response to sinusoidal inputs delivered to the lip vermilion at 5, 10, 50, and 150 Hz while adult participants engaged in a baseline condition (no force), 2 low-level lip force recruitment tasks differing by rate (0.1 Hz or 2 Hz), and passive displacement of the lip as a control to approximate the mechanosensory consequences of voluntary movement.

ResultsLL-VDTs increased significantly for test frequencies at or below 50 Hz during voluntary lip force recruitment. LL-VDT shifts were positively related to changes in the rate of lip force recruitment, whereas passively imposed displacements of the lip were ineffective in shifting LL-VDTs.

ConclusionsThese findings are considered in relation to published reports of force-related sensory gating in orofacial and limb systems and the potential role of somatosensory gating along the trigeminal system during orofacial behaviors.

Acknowledgments
This project was supported in part by National Institute on Deafness and Other Communication Disorders Grant R01 DC00365-08 and by Neuro-Logic Incorporated (Lawrence, Kansas). We express deep gratitude to Donald Finan and Amitava Biswas for their assistance with signal processing routines and technical issues.
Order a Subscription
Pay Per View
Entire Journal of Speech, Language, and Hearing Research content & archive
24-hour access
This Article
24-hour access