予測反応事態の眼球運動からマイクロサッカードを検出する試み
－テニスのサービスに対する予測反応課題を用いて－

抄録

     To evaluate the effects of visual attention on anticipatory response, we attempted to detect microsaccades from eye movements during anticipatory response tasks, which consisted of three conditions, free viewing and two fixational conditions toward ball-racquet impact and ball-release areas, using video image of tennis serve. Eight expert female tennis players participated the experiment voluntarily. In the free viewing condition, they were required to explore serve motions freely on a display, and to predict a direction of serve by pushing a right or left button as accurately and quickly as possible. In the two fixational conditions, they were asked to fixate constantly a target of blue circle (diameter twelve pixels) superimposed on ball-racquet impact area or ball-release area of serve motions, and to respond in the same way as in the free viewing condition. We used an algorithm of “Engbert and Kliegl (2003) ” for the detection of microsaccades. As a result, we found that microsaccades were detected from eye movements in the both fixationl conditions and not the free viewng condition. The results in the fixational condition toward release area indicated that the frequency of microsaccades lowered as visual attention increased when some cues of serve motions for anticipation existed in a distant area from the fixational target. And the direction of microsaccades showed the direction of ball-racquet impact area after ball release. Hence, it was concluded that microsaccades could be detected from eye movements during anticipatory response tasks using video image, if the subjects tried to fixate the fixational target, and the microsaccades would be an indicator of covert attention for anticipatory response.