Affiliations: [a] Life Sciences Research Laboratories, NASA Johnson Space Center, Houston, TX, USA | [b] Wyle Life Sciences, Houston, TX, USA | [c] Dept. Of Biological Sciences, Mount Holyoke College, South Hadley, MA, USA | [d] Bobby R. Alford Department of Otorhinolaryngology and Communicative Sciences, Baylor College of Medicine, Houston, TX, USA
Note: [*] Address correspondence to: Jacob J. Bloomberg, PhD, Life Sciences Research Laboratories, NASA-Johnson Space Center, Mail Code: SD3, Houston, TX 77058, USA. Tel.: +1 281 483 0436; Fax: +1 281 244 5734; E-mail: jbloombe@ems.jsc.nasa.gov
Abstract: The goal of the present study was to determine if adaptive modulation of vestibulo-ocular reflex (VOR) function is associated with commensurate alterations in manual target localization. To measure the effects of adapted VOR on manual responses we developed the Vestibular-Contingent Pointing Test (VCP). In the VCP test, subjects pointed to a remembered target following passive whole body rotation in the dark. In the first experiment, subjects performed VCP before and after wearing 0.5X minifying lenses that adaptively attenuate horizontal VOR gain. Results showed that adaptive reduction in horizontal VOR gain was accompanied by a commensurate change in VCP performance. In the second experiment, bilaterally labyrinthine deficient (LD) subjects were tested to confirm that vestibular cues were central to the spatial coding of both eye and hand movements during VCP. LD subjects performed significantly worse than normal subjects. These results demonstrate that adaptive change in VOR can lead to alterations in manual target localization.
