SIMULATION STUDY OF REACTION-TIMES AT VARYING VISUAL ANGLES

This paper focuses on the experiments of visual field in the horizontal plane and derives mathematical equations of both the experimental and the simulated reaction times of different subjects. A simple reaction time experiment was set up to test 50 subjects at various angles on both sides of the subjects head at standard line of sight of zero degree and their reaction times were noted. The experimental results were analysed and a mathematical relation was obtained. A FORTRAN based simulation model was developed which simulated 500 subjects and the simulated reaction times of the subjects were obtained. The results indicate that the reaction time takes much longer when the stimulus appear in the periphery of the horizontal visual field. This points at the fact that critical objects in a vigilance or monitoring tasks should be placed at approximately 40 degrees in the horizontal plane on either side of the center. The simulated results validate the mathematical relationship obtained from the experimental results. The use of simulation technique in such a problem has reinforced the laboratory findings to help derive conclusions that could be used with greater confidence by the researchers and man-machine system designers. This study also presents a model to predict reaction time at varying visual angles with the visual field of 80 degrees left and right in the horizontal plane. Simple reaction time which refers to a single stimulus and a single response option is a very important phenomenon in a number of human factors, safety and psychological studies. Human visual fields including preferred viewing angle and areas are crucial in designing several human machine systems including display and control panels of various types and other interfaces.