This research addresses usability of guide signs at railway stations for elderly passengers by understanding how a deficit in cognitive functions affects their behavior. The cognitive functions include planning, attention, and working memory, known to decrease independently with aging and indispensable for performing station tasks. We conducted two field surveys. In the first survey, paper-based cognitive-ability-assessment tests were issued for a total of 168 elderly participants. Based on their scores, four groups were defined; one with no problem and the other three with one inferior cognitive function. Each of three participants from each group performed tasks, such as transferring from line A to line B and using facilities at train stations, at one of three stations (Akihabara, Ohmiya, and Sugamo). In the second survey, a total of 154 elderly participants took the paper-tests, and three groups, each of which had one normal cognitive function, were defined. Three from each group with different use experience performed tasks at two stations (Tokyo and Shibuya) . The results showed that 1) persons with inferior planning function with normal attention function did not use guide signs when they had mental model, whereas they did not gather task-relevant information but irrelevant one when they had no mental models because of lack of definite task goals, causing them to get lost, and 2) persons with inferior planning function and inferior attention consistently had problems in gathering task-relevant information by using guide signs because of vague description of behavioral goals.

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A direction indicator should attract one's visual attention to the indicated direction effectively. Some studies using Posner's paradigm have showed that human eye gaze may pull our spatial attention to the gazed direction automatically. In this report errors and response times to a target that appears both in the same and the opposite location of the indicated direction were compared in seven types of direction indicators. Subjects participated in a target localization task. Stimulus Onset Asynchronies (SOAs) were set at 100ms, 200ms and 300ms. The responses to the target became either faster or slower when the target appeared in the same or opposite side of the indicated direction respectively when eyes and arrows were used. In contrast, the response times to the target were much less related to the indicated directions when characters were used as an indicator. Statistically significant error rates of responses were observed only when human face was used and the target appeared in the opposite directions.
The results indicate that human faces and/or gazes, when used as a direction indicator, may catch our visual attentions automatically to the indicated directions and may produce response errors when a target actually appears in the different directions. Chinese characters showed some extent of the automatic attention shifts for Japanese participants; English letters showed no such an effect, however.

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Physiological tremor referred to as tremor, a kind of mechanical vibration in biological systems, is studied. Tremor is a mechanical vibration of a body part such as an upper limb or finger. Fundamental research of tremor of the upper limb and its application are carried out. In this fundamental research, the mechanical vibration in both the vertical direction and the horizontal direction are simultaneously measured. The characteristic of tremor for healthy persons under the condition of maintenance of posture of raising the upper limb with instructed shoulder angle between the upper limb and body trunk and under the condition of the eyes closed are studied. The total power of the tremor wave is evaluated. The main frequency component in the vertical direction has a lower frequency at around 3Hz, while that in the horizontal direction has a higher frequency at around 10Hz, which is the alpha rhythm. These generated components correspond to the mechanical component and the component in the upper control nervous system, respectively. The contribution of the components under the conditions of joint angle of shoulder and kinds of shoulder joint disorder is revealed. In the application research, the tremors for three kinds of disorders, which are (a) rotator cuff tear or cut of tendon, (b) periarthritis humeroscapularis or frozen shoulder around the age of forty to fifty, and (c) loose shoulder or floating shoulder, are measured. The total power of the shoulder disorders on the disorder side of the upper limb is larger than that on the non-disorder side. The shape and frequency component of the power spectra for the three kinds of shoulder disorders show respective characters, thus the power spectra cause the shoulder disorders to discriminate.

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The present study investigated the quantification of hazard cognition of drivers depended on their ages. Ten young subjects and ten old subjects were asked to drive a virtual car along with the sine-wave curve in the 3D driving simulator. It was found by analysis of cross-correlation between the car position and the curved road, that all subjects handled preceding the change of curved road in almost all courses. And the number of course-out of the old subjects was larger than the young, while the driving speed of the old subjects was 50% as high as the speed of the young. These results were summarized as follows. Old people drove slowly and handled preceding the change of curved road so that they could compensate the delay of their response. Nevertheless, this compensation was not enough to drive safely.

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