Directional preponderance in pitch circular vection

2000 ◽  
Vol 10 (2) ◽  
pp. 93-98
Author(s):  
H. Fushiki ◽  
S. Takata ◽  
K. Yasuda ◽  
Y. Watanabe
Keyword(s):  
Stimulus Presentation ◽  
Vertical Axis ◽  
Directional Asymmetry ◽  
Stripe Pattern ◽  
Circular Vection ◽  
Significant Difference ◽  
Perception Of Self ◽  
Self Motion ◽  
Random Dot Pattern ◽  
Rotational Stimulation

We used optokinetic stimulation (OKS) in eighteen normal adults aged 18–30 years to investigate vertical self-motion perception. In order to induce self-rotation, either a stripe pattern or a random dot pattern was projected onto the inner wall of a hemispherical dome with a diameter of 150 cm. The pattern was rotated either about the subject’s vertical axis (yaw) or about the subject’s interaural axis (pitch) for 80 s at a constant acceleration of 1 deg / s 2 . Stimuli were randomly repeated three to four times in each direction. The latency of onset as well as the perceived intensity of circular vection (CV) was measured for each stimulus presentation. CV latencies for upward rotational stimulation were significantly longer than those for downward rotational stimulation under both types of stimulus conditions. There was no significant difference in CV latency between rightward and leftward rotational stimulation. For most subjects, the magnitudes of the perceived CV for rightward rotational stimulation were equal to those for leftward rotational stimulation, whereas the magnitudes of the perceived CV for vertical stimulation showed large intersubject variability. These results provide additional evidence that fundamental differences exist between different types of self-motion. Possible explanations for the directional asymmetry in vertical perception of self-motion will also be discussed.

Influence of fixation on circular vection

2000 ◽  
Vol 10 (3) ◽  
pp. 151-155
Author(s):  
Hiroaki Fushiki ◽  
Satoru Takata ◽  
Yukio Watanabe
Keyword(s):  
Vertical Axis ◽  
Constant Acceleration ◽  
Circular Vection ◽  
Hemispherical Dome ◽  
The Mean ◽  
Fixation Points ◽  
Self Motion ◽  
Random Dot Pattern ◽  
Normal Adults ◽  
Moving Pattern

The contribution of fixation to latency of circular vection (CV) was examined in twenty-five normal adults aged 18–30 years. For induction of self-motion a random dot pattern was projected onto a hemispherical dome. The pattern was rotated either about the subject’s vertical axis or about their interaural axis at a constant acceleration of 1 deg / s 2 . For the group tested, the perceived CV latencies were significantly shorter with fixation than without fixation in both horizontal and vertical CV. The effect of fixation was pronounced in subjects with longer latencies. The mean CV latencies for two different fixation points between the subject’s eyes and the moving pattern did not differ significantly. Our results suggest that the potential influence of fixation must be carefully controlled in studies of visually induced self-motion. Possible explanations for the effect of fixation on the generation of CV will also be discussed.

scholarly journals Method to Grasp a Feeling of Being There by Turning a Head Forcibly while Watching a Tourism Video using a VR Headset

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1470
Author(s):  
Naoya Isoyama ◽  
Tsutomu Terada ◽  
Masahiko Tsukamoto
Keyword(s):  
Virtual Reality ◽  
The Other ◽  
Head Mounted Display ◽  
Sense Of Presence ◽  
Other Hand ◽  
Significant Difference ◽  
Perception Of Self ◽  
Left And Right ◽  
Being There ◽  
Self Motion

In virtual reality (VR) tourism, when watching a video of a tourist location, the feeling of presence improves the experience. Furthermore, it is desirable to be able to give a feeling of having been there before to the users visiting the site afterward. In this study, we aimed to reveal the factors that provide these feelings. We hypothesized that one of the factors is the perception of self-motion. Therefore, we proposed a method wherein the users were induced to turn their heads to the left and right when watching the video of a tourist site via a VR head-mounted display. We conducted two experiments and found that the proposed method conveyed the greatest sense of presence. On the other hand, there was no significant difference in giving the feeling of having been there between the proposed method and watching the video of the site on a PC.

scholarly journals Stimulus Eccentricity and Spatial Frequency Interact to Determine Circular Vection

Perception ◽  
1998 ◽  
Vol 27 (9) ◽  
pp. 1067-1077 ◽  
Author(s):  
Stephen Palmisano ◽  
Barbara Gillam
Keyword(s):  
Spatial Frequency ◽  
Optic Flow ◽  
Peripheral Vision ◽  
High Spatial Frequency ◽  
Object Motion ◽  
Frequency Pattern ◽  
Circular Vection ◽  
Perception Of Self ◽  
Self Motion ◽  
Stimulus Eccentricity

While early research suggested that peripheral vision dominates the perception of self-motion, subsequent studies found little or no effect of stimulus eccentricity. In contradiction to these broad notions of ‘peripheral dominance’ and ‘eccentricity independence’, the present experiments showed that the spatial frequency of optic flow interacts with its eccentricity to determine circular vection magnitude—central stimulation producing the most compelling vection for high-spatial-frequency stimuli and peripheral stimulation producing the most compelling vection for lower-spatial-frequency stimuli. This interaction appeared to be due, in part at least, to the effect that the higher-spatial-frequency moving pattern had on subjects’ ability to organise optic flow into related motion about a single axis. For example, far-peripheral exposure to this high-spatial-frequency pattern caused many subjects to organise the optic flow into independent local regions of motion (a situation which clearly favoured the perception of object motion not self-motion). It is concluded that both high-spatial-frequency and low-spatial-frequency mechanisms are involved in the visual perception of self-motion—with their activities depending on the nature and eccentricity of the motion stimulation.

scholarly journals Gender-specific analysis for the association between trunk muscle mass and spinal pathologies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yusuke Hori ◽  
Masatoshi Hoshino ◽  
Kazuhide Inage ◽  
Masayuki Miyagi ◽  
Shinji Takahashi ◽  
...  
Keyword(s):  
Muscle Mass ◽  
Bioelectrical Impedance ◽  
Vertical Axis ◽  
Impedance Analysis ◽  
Poor Quality ◽  
Trunk Muscle ◽  
Sagittal Vertical Axis ◽  
Cross Sectional ◽  
Lower Trunk ◽  
Significant Difference

AbstractWe investigated the relationship between trunk muscle mass and spinal pathologies by gender. This multicenter cross-sectional study included patients aged ≥ 30 years who visited a spinal outpatient clinic. Trunk and appendicular muscle mass were measured using bioelectrical impedance analysis. The Oswestry Disability Index (ODI), visual analog scale (VAS) score for low back pain, sagittal vertical axis (SVA), and EuroQol 5 Dimension (EQ5D) score were investigated to evaluate spinal pathology. The association between trunk muscle mass and these parameters was analyzed by gender using a non-linear regression model adjusted for patients’ demographics. We investigated the association between age and trunk muscle mass. We included 781 men and 957 women. Trunk muscle mass differed significantly between men and women, although it decreased with age after age 70 in both genders. Lower trunk muscle mass was significantly associated with ODI, SVA, and EQ5D score deterioration in both genders; its association with VAS was significant only in men. Most parameters deteriorated when trunk muscle mass was < 26 kg in men and < 19 kg in women. Lower trunk muscle mass was associated with lumbar disability, spinal imbalance, and poor quality of life in both genders, with significant difference in muscle mass.

Torsional eye movements are facilitated during perception of self-motion

1999 ◽  
Vol 126 (4) ◽  
pp. 495-500 ◽  
Author(s):  
K. V. Thilo ◽  
Thomas Probst ◽  
Adolfo M. Bronstein ◽  
Yatsuji Ito ◽  
Michael A. Gresty
Keyword(s):  
Eye Movements ◽  
Perception Of Self ◽  
Self Motion

The utility of supine radiographs in the assessment of thoracic flexibility and risk of proximal junctional kyphosis

2021 ◽  
pp. 1-7
Author(s):  
Francis Lovecchio ◽  
Renaud Lafage ◽  
Jonathan Charles Elysee ◽  
Alex Huang ◽  
Bryan Ang ◽  
...  
Keyword(s):  
Thoracic Spine ◽  
Lumbar Lordosis ◽  
Pelvic Tilt ◽  
Pelvic Incidence ◽  
Vertical Axis ◽  
Control Analysis ◽  
Proximal Junctional Kyphosis ◽  
Sagittal Vertical Axis ◽  
Significant Difference ◽  
Junctional Kyphosis

OBJECTIVE Supine radiographs have successfully been used for preoperative planning of lumbar deformity corrections. However, they have not been used to assess thoracic flexibility, which has recently garnered attention as a potential contributor to proximal junctional kyphosis (PJK). The purpose of this study was to compare supine to standing radiographs to assess thoracic flexibility and to determine whether thoracic flexibility is associated with PJK. METHODS A retrospective study was conducted of a single-institution database of patients with adult spinal deformity (ASD). Sagittal alignment parameters were compared between standing and supine and between pre- and postoperative radiographs. Thoracic flexibility was determined as the change between preoperative standing thoracic kyphosis (TK) and preoperative supine TK, and these changes were measured over the overall thoracic spine and the fused portion of the thoracic spine (i.e., TK fused). A case-control analysis was performed to compare thoracic flexibility between patients with PJK and those without (no PJK). The cohort was also stratified into three groups based on thoracic flexibility: kyphotic change (increased TK), lordotic change (decreased TK), and no change. The PJK rate was compared between the cohorts. RESULTS A total of 101 patients (mean 63 years old, 82.2% female, mean BMI 27.4 kg/m2) were included. Preoperative Scoliosis Research Society–Schwab ASD classification showed moderate preoperative deformity (pelvic tilt 27.7% [score ++]; pelvic incidence–lumbar lordosis mismatch 44.6% [score ++]; sagittal vertical axis 42.6% [score ++]). Postoperatively, the average offset from age-adjusted alignment goals demonstrated slight overcorrection in the study sample (−8.5° ± 15.6° pelvic incidence–lumbar lordosis mismatch, −29.2 ± 53.1 mm sagittal vertical axis, −5.4 ± 10.8 pelvic tilt, and −7.6 ± 11.7 T1 pelvic angle). TK decreased between standing and supine radiographs and increased postoperatively (TK fused: −25.3° vs −19.6° vs −29.9°; all p < 0.001). The overall rate of radiographic PJK was 23.8%. Comparisons between PJK and no PJK demonstrated that offsets from age-adjusted alignment goals were similar (p > 0.05 for all). There was a significant difference in the PJK rate when stratified by thoracic flexibility cohorts (kyphotic: 0.0% vs no change: 18.4% vs lordotic: 35.0%; p = 0.049). Logistic regression revealed thoracic flexibility (p = 0.045) as the only independent correlate of PJK. CONCLUSIONS Half of patients with ASD experienced significant changes in TK during supine positioning, a quality that may influence surgical strategy. Increased thoracic flexibility is associated with PJK, possibly secondary to fusing the patient’s spine in a flattened position intraoperatively.

Comparative Analysis of the Exposure and Surgical Freedom of the Endoscopic Extended Minipterional Craniotomy and the Transorbital Endoscopic Approach to the Anterior and Middle Cranial Fossae

2018 ◽  
Vol 17 (2) ◽  
pp. 174-181 ◽  
Author(s):  
Raywat Noiphithak ◽  
Juan C Yanez-Siller ◽  
Juan M Revuelta Barbero ◽  
Raymond I Cho ◽  
Bradley A Otto ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Standard Deviation ◽  
Minimally Invasive ◽  
Vertical Axis ◽  
Endoscopic Approach ◽  
Extended Version ◽  
Specific Approach ◽  
Significant Difference ◽  
Surgical Application ◽  
The Mean

AbstractBACKGROUNDNumerous minimally invasive approaches to the skull base have been successively developed. Knowledge of the surgical nuances of a specific approach may facilitate approach selection. This study sought to compare the nuances of an extended version of the minipterional craniotomy (EMPT) with those of the transorbital endoscopic approach (TOEA) to the anterior and middle cranial fossae (ACF and MCF, respectively).OBJECTIVETo quantitatively analyze and compare the area of exposure and surgical freedom between EMPT and TOEA to the ACF and MCF.METHODSEMPT and TOEA were carried out in 5 latex-injected cadaveric heads, bilaterally (10 sides). For each approach, the area of exposure, surgical freedom, and angle of attack were obtained with neuronavigation and statistically compared.RESULTSNo significant difference was found between the mean area of exposure of EMPT and TOEA at the ACF and MCF (P = .709 and .317, respectively). The mean exposure area at the ACF was of 13.4 ± 2.6 cm2 (mean ± standard deviation) and 13.0 ± 1.9 cm2 for EMPT and TOEA, respectively. Except for the crista galli, EMPT afforded a larger area of surgical freedom at all targets. EMPT also achieved significantly greater attack angles in vertical axis except to the crista galli. The horizontal attack angles to all targets were similar between approaches.CONCLUSIONEMPT and TOEA offer a comparable area of exposure at the ACF and MCF in the cadaver; however, the instrument maneuverability afforded by EMPT is superior. Further studies are necessary to better define their precise surgical application.

scholarly journals Aromatherapy with ylang ylang for anxiety and self-esteem: a pilot study

2014 ◽  
Vol 48 (3) ◽  
pp. 492-499 ◽  
Author(s):  
Juliana Rizzo Gnatta ◽  
Patricia Petrone Piason ◽  
Cristiane de Lion Botero Couto Lopes ◽  
Noemi Marisa Brunet Rogenski ◽  
Maria Júlia Paes da Silva
Keyword(s):  
Pilot Study ◽  
Essential Oil ◽  
Self Esteem ◽  
Physiological Parameters ◽  
Post Intervention ◽  
Temperature Method ◽  
Significant Difference ◽  
Perception Of Self ◽  
Cutaneous Application

Objective: To verify if the use of ylang ylang essential oil by cutaneous application or inhalation alters the anxiety and self-esteem perception and physiological parameters as blood pressure and temperature. Method : A pilot study with 34 professionals from a nursing group randomized in three groups: one received the ylang ylang essential oil by cutaneous application, the second received through inhalation and the third (placebo) received the ylang ylang essence through cutaneous application. The assessment was done by an Anxiety Inventory (IDATE) and the Dela Coleta self-esteem scale, applied on baseline, after 30, 60 and 90 days and after 15 days post-intervention (follow up). Results : In the pre and post-intervention intergroup analysis, there was a significant difference in self-esteem for the three groups (p values: G1=0.014; G2=0.016; G3=0.038). There were no differences in the analysis between groups for anxiety or for physiological parameters. Conclusion : It was found significant alterations only to the intergroup perception of self-esteem for the three groups.


scholarly journals Differences in Demographic and Radiographic Characteristics between Patients with Visible and Invisible T1 Slopes on Lateral Cervical Radiographic Images

2022 ◽  
Vol 11 (2) ◽  
pp. 411
Author(s):  
Sadayuki Ito ◽  
Hiroaki Nakashima ◽  
Akiyuki Matsumoto ◽  
Kei Ando ◽  
Masaaki Machino ◽  
...  
Keyword(s):  
Pilot Study ◽  
Surgical Planning ◽  
Vertical Axis ◽  
Sagittal Vertical Axis ◽  
Radiographic Images ◽  
T1 Slope ◽  
Group I ◽  
Significant Difference ◽  
The Mean ◽  
Flexion And Extension

Introduction: The T1 slope is important for cervical surgical planning, and it may be invisible on radiographic images. The prevalence of T1 invisible cases and the differences in demographic and radiographic characteristics between patients whose T1 slopes are visible or invisible remains unexplored. Methods: This pilot study aimed to evaluate the differences in these characteristics between outpatients whose T1 slopes were visible or invisible on radiographic images. Patients (n = 60) who underwent cervical radiography, whose T1 slope was confirmed clearly, were divided into the visible (V) group and invisible (I) group. The following radiographic parameters were measured: (1) C2-7 sagittal vertical axis (SVA), (2) C2-7 angle in neutral, flexion, and extension positions. Results: Based on the T1 slope visibility, 46.7% of patients were included in group I. The I group had significantly larger C2-7 SVA than the V group for males (p < 0.05). The C2-7 SVA tended to be larger in the I group, without significant difference for females (p = 0.362). Discussion: The mean C2-7 angle in neutral and flexion positions was not significantly different between the V and I groups for either sex. The mean C2-7 angle in the extension position was greater in the V group. The T1 slope was invisible in males with high C2-7 SVA.

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