対面した他者の視線から受ける奥行の知覚

摘要

In this study, we utilized two tasks in experiments by presenting a 3D-CG face model with changing its head and lighting-to-the-head orientations : the tasks were 1) direction judgment of "forward", "backward", or "depth around (near) myself and 2) position identification for various targets aligned horizontally. Results showed that the perceived "depth" of the eye-gaze directions were basically horizontal-angle-dependent. The perceived area of "forward-to-me" was able to be classified according to the following two perceptual processes: one was based on the condition of judged horizontal angle being "around me" then the degree of close-eyes (vergence) had been used, and another was based on the condition of judging horizontal angle was judged "averted to me" then the judgment has made by the larger degree of the eye-rotation. In the experiment 2, we computed the perceptual gap between perceived gaze position with the actual gaze direction by multiple-regression analysis, as a function of perceived eye-gaze in horizontal directions (left / right to subjects), head and lighting orientations. It was shown that the perceived eye-gaze position, involving the gap between a real target-position and the perceived position, had been well-expected by the simple linear regression of a multiple regression function by degree of the models' head, light, and eye-directions.%本研究では，視線を正確に制御できる三次元顔モデルを用いて，人間の視線知覚特性を調べる2つの実験を行った．実験1では，視線の対象との距離が変化した際の輻輳角（寄り目具合）を定量的に変化させて実験を行った．結果として，相手と対面した状況においては，自分より後方への視線に関しては正確に判断されない傾向がある事が明らかになった．また，「自分より前」を見ているという判断を行うためには，水平角度に関して正面を見ていると判断された上での輻輳による奥行きの判断，もしくは水平角度が大きい（非常に自分から逸れた位置にある）と判断された上で角度変位が大きな視線の向きを観察したことによる判断，という2つの知覚過程による領域に分類できることが示唆された．したがって，視線の奥行方向判断は，水平方向判断に大きく依存することが分かった．また実験2では，先行研究において調べられている，水平方向の頭部角度，照明角度の変動によって起こる視線知覚のズレの予測式を算出した．結果から、知覚される視線角度は、顔モデルの頭部、照明方向、眼球の角度により予測可能であることが明らかになった．