Ryuzo Ohno

Natural and man-made landscapes cannot be seen all at once; they must be experienced in a temporal sequence. Most previous studies, however, discuss and evaluate landscapes in terms of static scenes facing the observer. As an attempt at the scientific investigation of the dynamic nature of perception during locomotion, this paper first discusses theoretical considerations on environmental perception and constructs a hypothetical model. It then presents a new research tool to describe and analyze both the continuous stream of sequential visual information received from the physical environment and the human response to it during locomotion. This is followed by a brief review of some of the major empirical studies conducted by the Ohno Laboratory at the Tokyo Institute of Technology. Experimental studies involving a Japanese garden, outdoor space at a university campus, and building exit areas generally support the model’s validity and tools for environmental design.

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Pedestrians' Mental State and Path Choice at Urban Intersections

＜10th European Architectural Envisioning Association Conference, Envisioning Architecture, pp. 153-160, Sep. 2011. ＞　Teruyuki Isagawa, Ryuzo OHNO

People behave according to incoming information from the environment, which is selected consciously or unconsciously based on one’s mental state. Many researchers have discussed pedestrians’ path choice behavior in a certain situation such as an emergency, exploring, etc. However, previous research has focused on a specific situation. Therefore, it is not clear how the mental state in a certain situation influences pedestrians’ path choice. Herein we examine the influence of three different mental states, which are defined by the degree of urgency and consequence: urgent, resolute, and recreational. We conducted an experiment using a visual simulation system to present a scene of a Y-shaped intersection and asked the subject to choose a path. The stimuli were video images of 10 intersections selected from streets in Tokyo. Each video image was created by a series of photos taken at consecutive vantage points toward the intersection by a digital camera with a fish-eye lens. A virtual street was created inside a visual simulation laboratory using images projected on three screens (each 2.0 meters x 1.8 meters), which span a wide visual field. In the experiment. 32 subjects were asked to imagine that he/she was in the following four different scenarios: 1) “evacuation from a fire and smoke” (urgent state), 2) "searching for a fast-food shop" and 3) “searching for a nearby station” (resolute states), and 4) “strolling without a specific purpose” (recreational state). They were then asked to choose either the left or right route at 10 intersections for each scenario. After each choice, the subjects were asked the reason for their choice. Path choice preference significantly varied with the situation, i.e., the mental state. A total of 1240 reasons were given, and these were categorized into three groups based on relevant phases. In the first phase, subjects demanded information such as safety, schema of a specific place, novelty. Then they tried to search for environmental cues to meet their needs such as street width, slopes, and signs in the second phase. While in the third phase information was obtained from environmental cues such as spaciousness, liveliness, mystery, and the perception of following the main route. The results indicated that subjects demand distinctly different information according to the situation. Hence, one environment can provide different information depending on the mental state of the subject as he/she searches for environmental cues.  

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　Makoto Inagami and Ryuzo Ohno

Daily perception entails an immediate awareness of the environment surrounding the body. To explore its dynamic nature during locomotion, this study tests the hypothesis that significant changes in spatial volume induce the directional focusing (i.e., anisotropy) of environmental perception. To capture perceptual activity in its natural state, we have attempted an approach using the feeling of visual pressure (i.e., felt presence) caused by the surrounding environment. In the present experiment that uses a virtual reality setup, participants were required to continuously rate their feelings while moving along a virtual outdoor route. Their ratings were analyzed in relation to environmental measurements along the route, such as the visible area of buildings and the horizontal extent of surrounding space. The relationship between the ratings and measurements was explored by using two prediction models: with and without consideration of perceptual anisotropy. The results suggested that a consideration of anisotropy improved the prediction accuracy, thereby supporting our hypothesis.

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Ryuzo Ohno, Megumi Katayama, Toshinori Komatsuzaki, Masashi Soeda

Conventional visual simulators allow observers to move in the simulated space by using a mouse or a joy-stick without the kinesthetic feeling of motion. However, the link between visual image and body motion is important to perceive the environment, especially when people are walking. 
A visual simulator was developed to synchronize the subject's walking motion on the treadmill with the video image shown on a HMD. Its validity was examined by comparing the accuracy of distance estimation with the conventional video image without walking motion. The “distance reproduction” method was applied to measure the perceived distance: subjects walked 25 meter in a real setting without being told the distance, and were asked to move the same distance in different conditions. Since the distance estimation became accurate in the condition with the walking motion, the validity of this simulator was secured. 
The following experiment was intended to investigate the influence of physical environmental features on perceived distance by using the simulation system. We operated some features using a scale model of a route and examined their influences. Subjects were asked to "walk" through a path consisted of two spaces with different physical features, and to respond by showing the proportion of the length of those two spaces. The result revealed that the distance of a narrower and lower ceiling path where people perceive clearer line perspective and faster optical flow tends to be perceived longer.