Manifestations of Aging in Virtual Reality Implementation of Rod and Frame Test

Senior adults’ reliance on the visual frame of reference for spatial orientation is a manifestation of an age-related shift in cognitive style from field independence to field dependence. We implemented a virtual reality rod and frame test (VR-RFT) to assess visual field dependence (VFD) in n=39 young adults (20-30 years old) and n=43 seniors (60 years old and above). The subjects were asked to determine subjective visual vertical (SVV) for 19 angles of frame tilt (running from -45 degrees to 45 degrees in steps of 5 degrees). The strong VFD of seniors was manifested not only by the increased error in the determination of SVV (SVVE) but also in its distribution. For small and large frame tilt angles, seniors’ SVVE skewness and kurtosis were greater than those of young adults. The SVVE median dependence on frame tilt may be accounted for with a phenomenological model whose two parameters describe the strengths of primary (P) and secondary (S) visual attractors which subjects use to infer SVV: the edges of the frame and its imaginary diagonals. For young adults, these parameters were: PY=14.91 and SY=12.51. For seniors, we observed an over 50% increase in the strength of the primary attractor PS=26.31 while the strength of the secondary one was only weakly affected by aging: SS=13.74. We demonstrate that the asymmetry between the strength of attractors significantly contributes to SVVE made by seniors at large frame tilts. We hypothesize that a variant VR-RFT may be used in rehabilitation to reduce excessive VFD.

Field (In)dependence Flexibility Following a Virtual Immersion Is Associated With Cybersickness and Sense of Presence

Field dependence–independence (FDI) is a psychological construct determining an individual’s approach of the perception–cognition coupling. In virtual reality (VR) context, several studies suggest that an individual’s perceptive style is susceptible to shift toward a more FI mode through down-weighting of conflicting visual cues. The present study proposes to investigate the potential flexible nature of FDI following a virtual immersion and to assess if this flexibility might be associated with the subjective experience of VR. 86 participants explored a real-world–like virtual environment for approximately 10 min. FDI levels were measured before and after the VR exposure using the rod-and-frame test. Their subjective experience of VR was measured a posteriori (cybersickness and sense of presence) and used in order to build two experimental groups via a cluster analysis. The results showed that only participants with a poor subjective experience of VR (i.e., a low level of sense of presence associated with a high level of cybersickness) significantly shifted to a more FI mode, which is discussed as a sensory re-weighting mechanism. Pragmatical applications are discussed, and future studies are outlined, based on the conclusion that FDI might be more flexible than we thought, which could shed light on the psychophysiology of VR.

Visual-vestibular mismatch correlates with headache

BACKGROUND: Dizziness affects 20–30%of the general population. A subgroup of dizzy patients with chronic migraine suffers vertigo implying that the migraine has a vestibular component. Vestibular migraine remains a diagnosis of exclusion based on history. OBJECTIVE: A link between headaches and dizziness suggests that these individuals would demonstrate dizziness and instability in complex, dynamic visual environments as a result of an inability to correctly process conflicting visual and vestibular signals. METHODS: A convenience sample of 74 patients (22 men and 52 women; average age 56.2 years) who presented with complaints of dizziness participated. Effects of Visual-Vestibular Mismatch (VVM) were measured using a modified VVM questionnaire. Visual dependence was measured as the error to subjective visual vertical using a computerized Rod and Frame test. RESULTS: Forty-two participants (56.8%) tested positive for VVM. Of these, 68.9%were patients with concomitant complaints of headaches. Visual dependence was present in 41.5%of all patients but showed no significant correlation with headache. 22.2%of patients had visual dependence and complained of headaches. CONCLUSIONS: These results demonstrate that sensory reweighting occurs in patients experiencing dizziness and headache, supports the role of vestibular involvement in this disorder, and provides future direction for novel interventions.

Visual Verticality Perception in Spinal Diseases: A Systematic Review and Meta-Analysis

Patients diagnosed with traumatic or non-traumatic spinal pain and idiopathic scoliosis frequently suffer from imbalance. The evaluation of the perception of verticality by means of visual tests emerges as a quick and easy tool for clinical management of the balance disorders. Several studies have assessed the visual perception of verticality in spinal diseases obtaining controversial results. The aim of our study is to analyze the perception of visual verticality in subjects with several spinal diseases in comparison with healthy subjects. A meta-analysis was carried out. PubMed MEDLINE, Scopus, WoS, CINAHL, and SciELO databases were searched until January 2020. The standardized mean difference (SMD) was calculated to analyze differences between patients and healthy controls. Fifteen studies with a total of 2052 patients were included. In comparison with healthy subjects, a misperception of verticality was found in patients with spinal pain when the perception of the verticality was assessed with the rod and frame test (SMD = 0.339; 95% confidence interval (CI) = 0.181, 0.497; p < 0.001). It seems that the perception of visual verticality is not altered in patients with idiopathic scoliosis (p = 0.294). The present meta-analysis shows a misperception of visual verticality only in patients with spinal pain.

VISUAL-VESTIBULAR AND POSTURAL ANALYSIS OF MOTION SICKNESS, PANIC, AND ACROPHOBIA

Background: Visual-vestibular and postural interactions can act as cues that trigger motion sickness and can also have a role in some anxiety disorders. We explore a method to detect individual sensitivity to visual-vestibular unusual patterns, which can signal a vulnerability to develop motion sickness and possibly anxiety disorders such as a fear of heights and panic. Material/Methods: 65 undergraduate students were recruited for the purposes of this study as voluntary participants (44 females); average age 21.65 years (SD=2.84) with normal or corrected to normal vision, without vestibular or postural deficiencies. Panic was assessed with the Albany Panic and Phobia Questionnaire, Motion Sickness with the Motion Sickness Susceptibility Questionnaire and Acrophobia was assessed by means of the Acrophobia Questionnaire. The Sharpened Romberg Test was used to test participant’s postural balance. The Rod and Frame Test (RFT) measures the participant’s ability to align a rod to the vertical within a titled frame providing a measure of error in the perception of verticality by degrees. This test was changed to measure the error offered when a participant’s head was tilted, and to trace the error caused by manipulating the vestibular system input. Results: The main findings show only motion sickness to be correlated with significant errors while performing a visual-vestibular challenging situation, and fear of heights is the only anxiety disorder connected with postural stability, although all disorders (fear of heights, panic and motion sickness) are correlated between each other in the self-report questionnaires. Conclusions: All disorders are correlated to each other in the surveys, and might have some common visual-vestibular origin, in theory. The rod and frame test was exclusively correlated with motion sickness whereas the postural stability test only displayed sensibility to acrophobia. Panic disorder was correlated to neither the RFT nor the Romberg. Although this method was initially employed to increase sensibility in order to detect anxiety disorders, it ended up showing its value in the detection of motion sickness.

Assessment of visual field dependence: Comparison between the mechanical 3D rod-and-frame test developed by Oltman in 1968 with a 2D computer-based version

The identification of subject’s perceptual style regarding multisensory integration is a central issue for spatial perception and sensorimotricity. In spatial orientation studies, the weighting of visual frame of reference (visual field dependence) is classically assessed by using verticality perception tasks, and especially the mechanical 3D rod-and-frame test (3D RFT). The validation of a 2D computer-based version of the RFT by virtue of its portability would facilitate the identification of modes of spatial referencing for the design and evaluation of sensory and motor rehabilitation programs. We question here whether the computerized 2D RFT yields frame effects similar (in amplitude, direction) and correlated to those induced by the mechanical 3D RFT. In both devices, 35 young and healthy males’ subjects were seated and tasked with aligning a rod to the gravity vertical within a square frame that was tilted at 18Âř. The results showed significantly larger rod deviations from the verticality in the 3D RFT. 3D and 2D RFT errors significantly correlated but shared a small amount of common variance ( r 2 = 0.35). In addition, left-right tilt asymmetry changes from one device to another. These results suggest that the mechanical 3D RFT for verticality perception remains a more robust test for identifying the subject’s perceptual style.