Naslov
Electrotactile Stimulation of the Tongue: Vestibular Sensory Substitution for Postural Control

Autori
Ivković, Vladimir

Vrsta, podvrsta i kategorija rada
Ocjenski radovi, magistarski rad

Fakultet
International Space University

Mjesto
Strasbourg, Francuska

Datum
28.08

Godina
2006

Stranica
78

Mentor
Mukai, Chiaki

Neposredni voditelj
Forth, Katharine E.

Ključne riječi
Electrotactile; Sensory substitution; Vestibular; Postural control

Sažetak
Loss or impairment of vestibular sensory input causes impaired postural control, ataxias, nausea and disturbed motor performance. Vestibular deficiencies are caused by traumas to inner ear or associated nerves, neurodegenerative processes and changes in baseline gravity environments. Postflight vestibular deconditioning is a significant operational and medical problem encountered by astronauts on long-duration missions. Vestibular deficiencies also present a significant public health issue since they are associated with an increased risk of falling in the elderly. Sensory substitution is a potentially beneficial technique for treatment of vestibular deficiencies. Contemporary research on sensory substitution has yielded significant results demonstrating its effectiveness and potential for a broad range of applications (Bach-y-Rita 2004). Particularly good results have been obtained by electrotactile stimulation through tongue brain-machine interfaces (BMI ; Bach-y-Rita 2004, Bach-y-Rita et al. 1998a, Bach-y-Rita et al 1998b). Vestibular electrotactile sensory substitution was demonstrated to be effective in improving postural control of vestibular-deficient patients (Scinicariello et al. 2001, Tyler et al. 2003) and to cause a transitory postural stabilization after-effect attributable to motor learning (Tyler et al. 2003). However these results have not been replicated in a sample of a normal population. This study was conducted in order to provide empirical data on the effects of vestibular sensory substitution through electrotactile stimulation of the tongue BMI on postural control in a sample of a normal population. Postural control measures were recorded using a Computerized Posturography System (CDP ; NeuroCom International, Clackamas, OR) while vestibular sensory substitution was delivered through electrotactile stimulation of the tongue by the Brainport TM Balance Device (tongue electrotactile display – TED ; Wicab Inc. Middleton, WI). The test protocol consisted of a series of modified sensory organization tests (SOT) performed on the CDP platform with or without the use of TED. The aims of this study were to determine whether sensory substitution improves postural control measures, whether any learning effects develop resulting from usage of TED and whether there are sex differences in the effects of sensory substitution on postural control. The results of the study indicate that the TED usage is beneficial for the postural control in challenging somatosensory conditions where inputs from multiple sensors – including the vestibular inputs – are compromised. This is particularly true for conditions simulated by dynamic SOT4 sensory environments. Obtained results support a novel hypothesis based on several assumptions – that electrotactile vestibular sensory substitution is most beneficial when it is used as a cognitive background sensory input while the cognitive focus is placed on postural control mechanisms aimed at maintaining balance in challenging dynamic environments where proprioceptive sensory inputs are compromised. Statistical analysis on obtained data suggests that the TED effect on postural control is strong enough in dynamic sequences of the compromised proprioceptive sensory environment. These data suggest that a learning process may be a result of TED usage. Additional study of the learning effects needs to be conducted on a larger sample of subjects to confirm or reject the results obtained in this study. No significant differences between male and female subjects were recorded on postural control measures. A tendency for higher scores was observed in female subjects. Additional study of these tendencies is required. The results support continuing research of electrotactile sensory substitution through the tongue BMI.

Izvorni jezik
Engleski

Znanstvena područja
Biologija, Kliničke medicinske znanosti, Biotehnologija

Napomena
Istraživanje provedeno u Neurosciences Laboratory - NASA Johnson Space Center (Houston, TX, SAD) i University of Texas Medical Branch (Galveston, TX, SAD)

POVEZANOST RADA