Abstract
Concurrent body movements have been shown to enhance the accuracy of spatial judgment, but it remains unclear whether they also contribute to perceptual estimates of gravitational space not involving body movements. To address this, we evaluated the effects of static or dynamic arm movements during prolonged whole-body tilt on the subsequent perceptual estimates of visual or postural vertical. In Experiment 1, participants were asked to continuously perform static or dynamic arm movements during prolonged tilt, and we assessed their effects on the prolonged tilt-induced shifts of subjective visual vertical (SVV) at a tilted position (during-tilt session) or near upright (post-tilt session). In Experiment 2, we evaluated how static or dynamic arm movements during prolonged tilt subsequently affected the subjective postural vertical (SPV). In Experiment 1, we observed that the SVV was significantly shifted toward the direction of prolonged tilt in both sessions. The SVV shifts decreased when performing dynamic arm movements in the during-tilt session, but not in the post-tilt session. In Experiment 2, as well as SVV, the SPV was shifted toward the direction of prolonged tilt, but it was not significantly attenuated by the performance of static or dynamic arm movements. The results of the during-tilt session suggest that the central nervous system utilizes additional information generated by dynamic body movements for perceptual estimates of visual vertical.
Highlights
Knowledge of the gravitational direction is fundamental to our action and perception of the earth
No significant differences were noted between the Static and No-movement conditions (p = 0.46, effect size r = 0.19). These results indicate that the subjective visual vertical (SVV) shifts that occurred during prolonged tilt were attenuated when performing dynamic arm movements
In Experiment 1, we found that the performance of dynamic arm movements effectively attenuated the SVV shifts that occurred during prolonged tilt, but not after prolonged tilt
Summary
Knowledge of the gravitational direction is fundamental to our action and perception of the earth. Numerous psychophysical studies have demonstrated the involvement of visual [1,2,3], somatosensory [4,5,6], and vestibular sensory signals [3, 7] in estimates of gravitational direction. Recent studies using computational modeling have shown that the central nervous system (CNS) weighs and combines these multisensory signals with prior knowledge and experience about the earth-vertical direction in a statistically optimal manner to resolve sensory ambiguity [7,8,9]. One typical way to evaluate internal estimates of the gravitational direction is the subjective visual vertical (SVV).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: 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.
