(verbatim from the application) The long-term goal of this project is to understand how sensorimotor integration of proprioceptive, visual, and vestibular information contributes to postural stability in humans. A complete understanding of postural control requires knowledge of how balance is maintained when the sensory integration process is challenged by conditions that limit and/or alter the available sensory cues, and that alter body dynamics. The principal hypothesis of this proposal is that this integration process is actively regulated. To demonstrate and characterize this active regulation, the focus of the research is on postural responses associated with transitions which suddenly limit or restore orientation cues or suddenly change body dynamics. The proposed experiments are motivated by recently acquired data that demonstrate characteristic transient oscillatory body sway following environmental transitions which suddenly restore accurate orientation cues. Modeling studies suggest that the observed oscillatory behavior is caused by an over generation of corrective leg muscle torque. The rapid restoration of normal, non-oscillatory body sway suggests that a sensorimotor regulatory mechanism exists that is able to quickly reduce corrective torque to an appropriate level. Additionally, preliminary results indicate that this regulatory mechanism is present in subjects with bilaterally absent vestibular function, but that this mechanism is compromised, possibly making vestibular loss subjects more susceptible than normals to instability following environmental transitions which alter the available sensory orientation cues. There are two specific aims of the proposed work.
The first aim i s to characterize the properties of neural mechanisms that actively regulate the human postural control system to achieve optimal dynamic control of balance in changing environments. The second is to characterize nonlinear properties of the vestibular contribution to postural control, and to understand how this nonlinear behavior contributes to the sensorimotor integration process. The proposed research relies on a model-based approach to explain and predict postural behavior determined by sensorimotor regulatory mechanisms involved in the sensory integration process. Abnormalities involving the active regulation of sensorimotor integration and gain control may be an unrecognized source of instability and falls. A better understanding of these active regulatory processes may lead to new rehabilitation methods and improved clinical balance function tests.
|Goodworth, Adam D; Mellodge, Patricia; Peterka, Robert J (2014) Stance width changes how sensory feedback is used for multisegmental balance control. J Neurophysiol 112:525-42|
|Goodworth, Adam D; Peterka, Robert J (2012) Sensorimotor integration for multisegmental frontal plane balance control in humans. J Neurophysiol 107:12-28|
|Dozza, Marco; Chiari, Lorenzo; Peterka, Robert J et al. (2011) What is the most effective type of audio-biofeedback for postural motor learning? Gait Posture 34:313-9|
|van der Kooij, Herman; Peterka, Robert J (2011) Non-linear stimulus-response behavior of the human stance control system is predicted by optimization of a system with sensory and motor noise. J Comput Neurosci 30:759-78|
|Goodworth, Adam D; Peterka, Robert J (2010) Influence of stance width on frontal plane postural dynamics and coordination in human balance control. J Neurophysiol 104:1103-18|
|Goodworth, Adam D; Peterka, Robert J (2010) Influence of bilateral vestibular loss on spinal stabilization in humans. J Neurophysiol 103:1978-87|
|Goodworth, Adam D; Wall 3rd, Conrad; Peterka, Robert J (2009) Influence of feedback parameters on performance of a vibrotactile balance prosthesis. IEEE Trans Neural Syst Rehabil Eng 17:397-408|
|Peterka, Robert J (2009) Comparison of human and humanoid robot control of upright stance. J Physiol Paris 103:149-58|
|Goodworth, Adam D; Peterka, Robert J (2009) Contribution of sensorimotor integration to spinal stabilization in humans. J Neurophysiol 102:496-512|
|Kluzik, Joann; Peterka, Robert J; Horak, Fay B (2007) Adaptation of postural orientation to changes in surface inclination. Exp Brain Res 178:1-17|
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