Yasuyoshi Kuba

Aging and Shifts of Visual Attention in Saccadic Eye Movements

The authors examined age-related differences in target discrimination before the saccade to investigate the influence of aging on the facilitation of target discrimination by shifts of attention. Older and younger adults made saccades toward a peripheral stimulus after its onset and discriminated the orientation of the stimulus. Mean saccadic latency was greater for older adults than for younger adults. Facilitation of target discrimination immediately before the saccades was found both in older and younger adults. These results suggest that aging affects the properties of saccades but does not affect the properties of attentional shifts immediately before a saccade.

An interfacing method between an artificial hand and human

First, the flexible grasping motion control for a hand with two fingers is explained. For this control the reference grasping force must be decided in advance of the operation and the property of the reference grasping force is explained. Second, the way to extend the grasping control by including the operator to the control loop is explained. Through consideration of the property of the reference grasping force the design of the master hand mechanism is explained.<<ETX>>

Audio signals in domestic appliances evaluated in terms of the hearing ability of older adults

The audio signals used in domestic appliances currently available on the market in Japan were recorded to identify suitable signals for the hearing ability of older adults. The results of the analysis indicated the following three problems: (1) Some appliances use high‐frequency tones around 4000 Hz. Since these sounds are hard for older adults with presbycusis to hear, it would be better to use signals with lower frequencies. However, the problem here is that if the frequency is lowered, then the signal might be masked by domestic sounds whose power would be greater relative to the low‐frequency signals. (2) The signals used by some appliances are too soft. The intensity of some signals should be adjusted to compensate for the hearing loss among older adults. (3) The sounds used in these appliances are often very similar in terms of both timbre and temporal ringing patterns. That may cause confusion because it is difficult to identify which appliance is signaling.