Consideration of the 'sensory-motor coordination' to an optic and acoustic stimulation

It is necessary to know how quickly and how accurately humans can react when sensory stimulations are presented around them in order to construct a virtual reality system. We have been studying how quickly and accurately subjects can indicate targets such as a bursting sound and a flashing light presented around them without seeing their arm. The motion induced by the sensory stimulation is called "sensory-motor co-ordination". In this report, the angle error between the indicated angle and the target angle was measured as a function of the target angle (Case 1). This result was compared with the angle error between the indicated angle and the angle informed by an operator using spoken words (Case 2). In the experimental setup, the 19 LEDs and speakers were arranged inside a hemi-spaced cylinder and the distance from the subject to the targets was 0.5 m. The duration of the presented targets was 0.2 sec. The indicated angles were detected by a touch panel attached to the hemispaced cylinder. The subjects were asked not to move their head or eyes during the experiment. From the experimental results, the degree of error increased in the peripheral area, and the error in case 1 was smaller than in case 2. We discussed the reason for this and the design of virtual reality systems.<<ETX>>