Ikeda Hanako, Watanabe Katsumi, Cavanagh Patrick
College of Contemporary Psychology, Rikkyo University, Saitama, Japan.
J Vis. 2013 Mar 26;13(4):20. doi: 10.1167/13.4.20.
It is difficult to identify a target in the peripheral visual field when it is flanked by distractors. In the present study, we investigated this "crowding" effect for biological motion stimuli. Three walking biological motion stimuli were presented horizontally in the periphery with various distances between them, and observers reported the walking direction of the central figure. When the inter-walker distance was small, discriminating the direction became difficult. Moreover, the reported direction for the central target was not simply noisier, but reflected a degree of pooling of the three directions from the target and two flankers. However, when the two flanking distractors were scrambled walking biological motion stimuli, crowding was not seen. This result suggests that the crowding of biological motion stimuli occurs at a high-level of motion perception.
当外周视野中的目标两侧伴有干扰物时，很难识别该目标。在本研究中，我们调查了生物运动刺激的这种“拥挤”效应。三个行走的生物运动刺激以水平方式呈现于外周视野，它们之间有不同的间距，观察者报告中央人物的行走方向。当行走者之间的距离较小时，辨别方向变得困难。此外，报告的中央目标方向并非仅仅是噪声更大，而是反映了来自目标和两个侧翼干扰物的三个方向的某种程度的合并。然而，当两个侧翼干扰物是杂乱的行走生物运动刺激时，未观察到拥挤现象。这一结果表明，生物运动刺激的拥挤发生在运动感知的高级阶段。
