Yuki Mori

Changes in Brain Blood Flow by the Use of 2D/3D Games

Recently, with the rapid progress in image processing and three-dimensional (3D) technology, stereoscopic images are not only seen on television but also in theaters, on game machines, etc. However, symptoms such as eye fatigue and 3D sickness may be experienced when viewing 3D films on displays and visual environments. The influence of stereoscopic vision on the human body has been insufficiently understood; therefore, it is important to consider the safety of viewing virtual 3D content. In this study, we examine whether exposure to 3D video clips affects the human body such as brain blood flow. Subjects viewed 3D video clips on the display of portable game machines, and time series data of their brain blood flow was measured by near-infrared spectroscopy (NIRS) with use of FOIRE-3000 (Shimazu Co. Ltd., Kyoto). Our results showed oxyhemoglobin tended to increase throughout the cerebral cortex while operating the game machines on the 3D display in comparison with the 2D display.

Effect of Background Viewing on Equilibrium Systems

Our previous study indicated an increase in the sway values that were observed during peripheral viewing. Especially in the background, there are large differences between human binocular images and artificial stereoscopic images, to which our convergence corresponding to depth cues is not accommodated. This is why equilibrium functions are affected by peripheral viewing. In the present paper, we examine the effect of the exposure to stereoscopic video clips without the background on our equilibrium function. Fifteen healthy young males voluntarily participated and maintained the Romberg posture in stabilometry. Their stabilograms were recorded during monocular vision or binocular parallax vision using semipermeable smart glasses. We also measured the body sway with the subjects’ eyes closed 0–3 min after the exposure to the video clips. A statistical comparison indicated that our equilibrium function is significantly affected by video clips with the background 0–2 min after the exposure to the video clips.

A study of the relationship of equilibrium function and the cerebrum blood flow with alcohol intake

The severity of alcohol-related impairment increases in proportion to alcohol intake. The centrostaltic cerebrum is suppressed with increased alcohol intake, with symptoms including staggering gait and motility disturbance. In this study, we focused on the deterioration of equilibrium function with the above-mentioned suppression under the influence of alcohol. We herein compared the time course of stabilometry with that of cerebrum blood flow by using fNIRS. We thus considered that equilibrium dysfunction would occur with alcohol ingestion due to inactivation of the cerebrum.

Effect of Viewing a Long Stereoscopic Film on Equilibrium Function and Autonomic Nervous System

OBJECTIVES Owing to the recent rapid advancements in image processing and three-dimensional (3-D) technologies, stereoscopic images can now be viewed on television as well as in theaters and on gaming consoles among others. However, with these advancements, there have also been reports on motion sickness and asthenopia induced by viewing stereoscopic films. Human equilibrium function deteriorates when viewing stereoscopic films, which may lead to motion sickness; however, the exact cause of such motion sickness remains unknown. Therefore, as part of hygiene research that contributes to society, it is important to consider the safety of viewing virtual 3D contents. METHODS In this study, we investigated the effects of viewing 2-D/3-D video clips on the human body by stabilometry, electrogastrography (EGG), and subjective assessments. Seven subjects aged 22 to 24 viewed 2-D/3-D video clips for 60 min. RESULTS A comparison of time series data obtained at rest shows a significant change in the EGG patterns 20 min after the start of viewing the video clips. Furthermore, sway values while viewing the 3-D video clips were considerably higher than those while viewing the 2-D video clips 60 min after the start of viewing. CONCLUSIONS These findings show that the autonomic nervous system is affected first by long-term viewing of stereoscopic films, and the equilibrium function deteriorates gradually over the course of the exposure.

Numerical Analysis of Body Sway While Viewing a 3D Video Clip Without Perspective Clues

Recently, with the rapid progress in image processing and three-dimensional (3D) technology, stereoscopic images are not only seen on television but also in theaters, on game machines, etc. However, symptoms such as eye fatigue and 3D sickness are experienced when viewing 3D films on displays and visual environments. The influence of stereoscopic vision on human body has been also insufficiently understood; therefore, it is important to consider the safety of viewing virtual 3D contents. The aim of this study is to examine the effects of exposure to 2D/3D video clips on human equilibrium systems. Stereoscopic video clips with complexly ambulated spheres and their monocular (2D) vision were shown to subjects using binocular parallax smart glasses. We compared stabilograms recorded during exposure to video clips with/without depth cues on 3D images. The time-average potential function was obtained from stabilograms using stochastic differential equations as a mathematical model for body sway to conduct a numerical analysis.