Closing an open-loop control system: vestibular substitution through the tongue

J Integr Neurosci. 2003 Dec;2(2):159-64. doi: 10.1142/s0219635203000263.


The human postural coordination mechanism is an example of a complex closed-loop control system based on multisensory integration [9,10,13,14]. In models of this process, sensory data from vestibular, visual, tactile and proprioceptive systems are integrated as linearly additive inputs that drive multiple sensory-motor loops to provide effective coordination of body movement, posture and alignment [5-8, 10, 11]. In the absence of normal vestibular (such as from a toxic drug reaction) and other inputs, unstable posture occurs. This instability may be the result of noise in a functionally open-loop control system [9]. Nonetheless, after sensory loss the brain can utilize tactile information from a sensory substitution system for functional compensation [1-4, 12]. Here we have demonstrated that head-body postural coordination can be restored by means of vestibular substitution using a head-mounted accelerometer and a brain-machine interface that employs a unique pattern of electrotactile stimulation on the tongue. Moreover, postural stability persists for a period of time after removing the vestibular substitution, after which the open-loop instability reappears.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acceleration
  • Adult
  • Brain / physiopathology
  • Electric Stimulation
  • Female
  • Head / physiopathology*
  • Humans
  • Male
  • Middle Aged
  • Neuronal Plasticity
  • Posture*
  • Sensory Aids*
  • Tongue / physiopathology*
  • Touch*
  • Vestibular Diseases / physiopathology*