小型船舶操船時の視覚的注意に関する予備的研究：2次元画像を使った“シミュレーション”実験

摘要

プレジャーボートや漁船といった小型船舶の事故rnは最近10年、全海難事故2300～2900件のうちの約rn60～70％を占めており、事故の主な原因は見張り不rn十分とされている。2007年度の海上保安庁統計rnによれば、見張り不十分にも様々な種類があり、そrnれらは①見張りを行わなかった、②相手船を認めたrnものの、その後の動静監視を行わなかった、③見張rnり態勢には就いていたものの、相手船、障害物等をrn見落とした、の3つに分類されている。%We measured the reaction time to detect a circle (0.6 deg arc in diameter), presented for 0.5 msec on two dimensional still and motion pictures, and the frequency of response errors to oversight it. The pictures were views of shore which was videotaped from a deck in the small boat, whose vessel speed was 0, 5, or 18 kt, at two different sea roads (near scenery and far scenery). Ten observers viewed the pictures projected on a big screen (27 deg arc x 43 deg arc) with the intention to simulate the navigation of the small boat. The results showed that 1) the reaction time for the still picture was less than those for the motion pictures and 2) the percentage of the oversight of the stimulus in the motion picture of near scenery with the highest speed was much higher than those in other pictures. Some implications of these results on the role of visual attention during the navigating arerndiscussed.