Abstract
Without relevant visual cues, the subjective visual vertical (SVV) is biased in roll-tilted subjects toward the body axis (Aubert or A-effect). This study focused on the role of the somatosensory system with respect to the SVV and on whether somesthetic cues act through the estimated body tilt. The body cast technology was used to obtain a diffuse tactile stimulation. An increased A-effect was expected because of a greater underestimation of the body position in the body cast. Sixteen subjects placed in a tilt chair were rolled sideways from 0 degrees to 105 degrees. They were asked to verbally indicate their subjective body position and then to adjust a luminous line to the vertical under strapped and body cast conditions. Results showed a greater A-effect (p < .001) but an overestimation of the body orientation (p < .01) in the body cast condition for the higher tilt values (beyond 60 degrees). Since the otolith organs produced the same gravity response in both conditions, errors were due to a change in somesthetic cues. Visual and postural errors were not directly related (no correlation). However, the angular distance between the apparent body position and the SW remained stable, suggesting that the change in somatosensory pattern inputs has a similar impact on the cognitive processes involved in assessing the perception of external space and the sense of self-position.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.