Jaw stretch reflexes in children.
The substantial morphological transformations that occur during human development present the nervous system with a considerable challenge in terms of motor control. Variability of skilled motor performance is a hallmark of a developing system. In adults, the jaw stretch reflex contributes to the functional stability of the jaw. We have investigated the response properties of the jaw stretch reflex in two groups of young children and a group of young adults. Response latencies increased with development, and all age groups produced stimulus-magnitude-dependent increases in reflex gain and resulting biting force. Reflex gain was largest for the older children (9-10 years), yet net increases in resulting biting force were comparable across age groups. These data and earlier experiments suggest that oral sensorimotor pathways mature throughout childhood in concert with the continued acquisition of complex motor skills.
Finan
Donald S
DS
Speech, Language, and Hearing Sciences and the Center for Neuroscience, University of Colorado, Boulder, CO 80309, USA. Don.Finan@colorado.edu
Smith
Anne
A
D000328:Adult; D000375:Aging / Q000502:physiology*; D001732:Bite Force; D002648:Child; D002675:Child, Preschool; D004576:Electromyography; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology; D008297:Male; D008334:Mandible / Q000502:physiology*; D008409:Mastication / Q000502:physiology; D008410:Masticatory Muscles / Q000294:innervation / Q000502:physiology*; D009048:Motor Skills / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology; D009470:Muscle Spindles / Q000502:physiology*; D009434:Neural Pathways / Q000254:growth & development; D011930:Reaction Time / Q000502:physiology; D012026:Reflex, Stretch / Q000502:physiology*; D013704:Temporomandibular Joint / Q000294:innervation / Q000502:physiology*; D014276:Trigeminal Nerve / Q000254:growth & development