A head-mounted display cannot cover an angle of visual field as wide as that of natural view (out-of-view problem). To enhance the visual cognition of an immersive environment, previous studies have ...developed various guidance designs that visualize the location or direction of items presented in the users’ surroundings. However, two issues regarding the guidance effects remain unresolved: How are the guidance effects different with each guided direction? How much is the cognitive load required by the guidance? To investigate the two issues, we performed a visual search task in an immersive environment and measured the search time of a target and time spent to recognize a guidance design. In this task, participants searched for a target presented on a head-mounted display and reported the target color while using a guidance design. The guidance designs (a moving window, 3D arrow, radiation, spherical gradation, and 3D radar) and target directions were manipulated. The search times showed an interaction effect between guidance designs and guided directions, e.g., the 3D arrow and radar shorten the search time for targets presented at the back of users. The recognition times showed that the participants required short times to recognize the details of the moving window and radiation but long times for the 3D arrow, spherical gradation, and 3D radar. These results suggest that the moving window and radiation are effective with respect to cognitive load, but the 3D arrow and radar are effective for guiding users’ attention to necessary items presented at the out-of-view.
The effect of spatial contexts on attention is important for evaluating the risk of human errors and the accessibility of information in different situations. In traditional studies, this effect has ...been investigated using display-based and non-laboratory procedures. However, these two procedures are inadequate for measuring attention directed toward 360-degree environments and controlling exogeneous stimuli. In order to resolve these limitations, we used a virtual-reality-based procedure and investigated how spatial contexts of 360-degree environments influence attention. In the experiment, 20 students were asked to search for and report a target that was presented at any location in 360-degree virtual spaces as accurately and quickly as possible. Spatial contexts comprised a basic context (a grey and objectless space) and three specific contexts (a square grid floor, a cubic room, and an infinite floor). We found that response times for the task and eye movements were influenced by the spatial context of 360-degree surrounding spaces. In particular, although total viewing times for the contexts did not match the saliency maps, the differences in total viewing times between the basic and specific contexts did resemble the maps. These results suggest that attention comprises basic and context-dependent characteristics, and the latter are influenced by the saliency of 360-degree contexts even when the contexts are irrelevant to a task.
Visual information can be used to plan, start, and coordinate manual movements in obstacle avoidance. An intriguing example of visuomotor coordination is the effect of wing-shaped walls, in which ...walls are oriented away from or toward a moving agent. A historical story from medieval Japan recounts that wing-shaped walls disrupted the agent's movement more when oriented toward the agent than when oriented away from the agent. This study aimed at examining whether the disruptive effect of wing-shaped walls occurs in a schematic situation represented on a 2D plane. In this study, we conducted psychophysical experiments in which participants were asked to move a stylus from a start point to a goal while avoiding multiple line obstacles that were arranged alternately at a course. In the two experiments, we manipulated the orientation and the size of the visible parts of the obstacles systematically. We found that the obstacles oriented toward the agent produced frequent contacts with the agent and attracted manual movements to the endpoints of obstacles. We discussed possible interpretations of the results in the context of attentional guidance.
The core of a Gigahertz Spin Rotation (GSR) sensor, a compact and highly sensitive magnetic sensor, is composed of Co-Fe-based amorphous magnetic wire with a diameter of 10 μm. Observations of the ...magnetic domain structure showed that this magnetic wire has unusual magnetic noise characteristics. Bamboo-shaped magnetic domains a few hundred micrometers in width were observed to form inside the wire, and smaller domains a few micrometers across were observed to form inside these larger domains. The magnetic domain pattern changed abruptly when an external magnetic field was applied to the wire. Herein is shown how these changes may be a source of magnetic noise in the wire.
Chorus waves are naturally occurring electromagnetic emissions in space and are known to produce highly energetic electrons in the hazardous radiation belt. The characteristic feature of chorus is ...its fast frequency chirping, whose mechanism remains a long-standing problem. While many theories agree on its nonlinear nature, they differ on whether or how the background magnetic field inhomogeneity plays a key role. Here, using observations of chorus at Mars and Earth, we report direct evidence showing that the chorus chirping rate is consistently related to the background magnetic field inhomogeneity, despite orders of magnitude difference in a key parameter quantifying the inhomogeneity at the two planets. Our results show an extreme test of a recently proposed chorus generation model and confirm the connection between the chirping rate and magnetic field inhomogeneity, opening the door to controlled plasma wave excitation in the laboratory and space.
A method to estimate orientation direction of liquid crystal molecules three-dimensionally under ultrasound excitation was proposed and the relationship between the ultrasound vibration and the ...molecular orientation was discussed. Our group have reported a technique to control orientation direction of liquid crystal molecules using ultrasound vibration which could be applied to an optical variable-focus liquid crystal lens. The lens consisted of a liquid crystal layer sandwiched by two glass circular discs and a piezoelectric ring. Ultrasound vibration induces change in the refractive index of the lens, enabling the variable-focus function. The three-dimensional orientation direction of the liquid crystal molecules in the lens was predicted from the transmitted light distributions under the crossed Nicol conditions. The liquid crystal molecules were inclined from vertical alignment by the ultrasound vibration, and larger ultrasound vibration gave larger inclination of the molecules. There was a strong correlation between the distributions of ultrasound vibration and the liquid crystal molecular orientation; the molecular orientation was changed remarkably between the antinodal and nodal parts of the ultrasound flexural vibration on the glass plate and the molecules aligned towards the antinode.
The zebrafish is widely used as a model in biological studies. In particular, the heart rate and cortisol levels of zebrafish are commonly measured to elucidate the pharmacological effects of ...chemical substances. Meanwhile, although ventilation is also an important physiological index reflecting emotion-like states, few studies have evaluated the effects of chemicals on ventilation in adult zebrafish. In this study, we assessed whether it is possible to evaluate the pharmacological effects elicited by caffeine in adult zebrafish under free-swimming conditions. We measured the ventilation in adult zebrafish exposed to multiple concentrations of caffeine under restraint and free-swimming conditions and evaluated the pharmacological effects of caffeine using linear mixed model analysis. In addition, results of electrocardiogram analysis and swimming speeds were compared with those in previous reports to ensure that an appropriate dose of caffeine was administered. Under restraint conditions, caffeine significantly decreased heart rate and increased ventilation in a concentration-dependent manner. Under free-swimming conditions, the ventilation rate significantly increased with increasing caffeine concentration. These results indicate that the pharmacological effects elicited by chemicals on ventilation can be evaluated in free-swimming zebrafish.
A layered metal–organic framework (MOF) comprising extra-large nanographene sheets, HBC MOF, was successfully synthesized using a dicarboxylic acid derivative of hexa-peri-hexabenzocoronene (HBCLH2), ...and its structure was characterized by single-crystal X-ray diffraction analysis. The crystal structure shows that 2D layers composed of a dinuclear Zn2+ complex unit and HBCL are located on top of each other through multiple weak interlayer bonds, affording HBC MOF, having three dimensionally connected nanopores with large nanographene surfaces. The HBC-based nanographene sheets are anchored to the MOF framework via two zinc carboxylate linkages and therefore have an axial rotational freedom. The sorption isotherms of gaseous molecules such as carbon dioxide and hydrocarbons (acetylene, propane, propylene, benzene, and cyclohexane) on HBC MOF all displayed a hysteretic profile with reversible structural changes, as observed by in situ powder X-ray diffraction studies.
Abstract
This study aimed to develop and validate a scale called the Futoko Spectrum Quotient (FSQ), which measures school absenteeism (
futoko
), as a method to achieve the early identification of ...at‐risk students. We recruited 673 students and 119
futoko
students from secondary schools and educational support centers. The results showed that the bifactor model had better fit, proposing a general (G) factor representing avoidance motivation and an orthogonal specific (S) factor representing psychological distress. We then examined the measurement invariance and continuity of the latent bifactor construct of the FSQ, correlations of the FSQ with external variables, and measurement reliability to validate the FSQ. Our findings highlight the need to focus on students’ mental state prior to the emergence of absence behaviors and the significance of the present scale in theory and practice.
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