Channel Information Capacity of the Sensomotor System of the Eye

Abstract

Most recent investigations on smooth pursuit and saccadic eye movements based on visuo-oculomotor system reaction to the predictable target jumps or movement trajectories do not fit real working situation. Visuo-oculomotor system of the operator during man and machine interaction and visuo-motor control is involved in searching and pointing or pursuing objects of interest witch position or trajectories are random. Study was performed to evaluate capability limit of the visuo-oculomotor system to pursue not predictable target or jump to random stimulus. For this task concept of the information theory was adopted. It was supposed that human visuooculomotor system is information transfer channel where target movement trajectory or jump position is input or source information and elicited smooth pursuit or saccadic eye movement errors are lost information. Information rate transferred through channel is defined as difference between input and lost information. Channel information capacity of the visuo-oculomotor system is calculated as a limit of transferred information threw channel during time unit. Experimental investigation of the human visuo-oculomotor system during smooth pursuit and saccadic eye movements was performed using LC Technology, Ltd. produced eye tracker “EyeGaze System”. After testing five subjects and calculations it was found that channel information capacity of the human visuo-oculomotor system during smooth pursuit is around 8 bites per second and around 7 bytes per second during saccadic eye movements. During calculations a few theoretical assumptions were accepted such as independence between horizontal and vertical neural channels of the visuo-oculomotor system and application of the Gaussian probability distribution for target and error signals. Bibl. 5 (in English; summaries in English, Russian and Lithuanian).