Weech Séamas, Troje Nikolaus F
Department of Psychology, Queen's University, Kingston, ON, Canada.
Department of Psychology, Queen's University, Kingston, ON, Canada; Department of Biology, Queen's University, Kingston, ON, Canada; School of Computing, Queen's University, Kingston, ON, Canada; Centre for Neuroscience Studies, Queen's University, Kingston, ON, Canada.
Iperception. 2018 Jan 9;9(1):2041669517750171. doi: 10.1177/2041669517750171. eCollection 2018 Jan-Feb.
Depth-ambiguous point-light walkers are most frequently seen as facing-the-viewer (FTV). It has been argued that the FTV bias depends on recognising the stimulus as a person. Accordingly, reducing the social relevance of biological motion by presenting stimuli upside down has been shown to reduce FTV bias. Here, we replicated the experiment that reported this finding and added stick figure walkers to the task in order to assess the effect of explicit shape information on facing bias for inverted figures. We measured the FTV bias for upright and inverted stick figure walkers and point-light walkers presented in different azimuth orientations. Inversion of the stimuli did not reduce facing direction judgements to chance levels. In fact, we observed a significant facing away bias in the inverted stimulus conditions. In addition, we found no difference in the pattern of data between stick figure and point-light walkers. Although the results are broadly consistent with previous findings, we do not conclude that inverting biological motion simply negates the FTV bias; rather, inversion causes stimuli to be seen facing away from the viewer more often than not. The results support the interpretation that primarily low-level visual processes are responsible for the biases produced by both upright and inverted stimuli.
深度模糊的点光行走者最常被视为面向观察者（FTV）。有人认为，FTV偏差取决于将刺激识别为人。因此，通过颠倒呈现刺激来降低生物运动的社会相关性已被证明可以减少FTV偏差。在这里，我们重复了报告这一发现的实验，并在任务中添加了简笔人物行走者，以评估明确的形状信息对倒置人物的朝向偏差的影响。我们测量了以不同方位呈现的直立和倒置简笔人物行走者以及点光行走者的FTV偏差。刺激的倒置并没有将朝向判断降低到随机水平。事实上，我们在倒置刺激条件下观察到了显著的背向偏差。此外，我们发现简笔人物行走者和点光行走者的数据模式没有差异。尽管结果与先前的发现大致一致，但我们并不认为颠倒生物运动会简单地消除FTV偏差；相反，倒置会导致刺激更多地被视为背向观察者。结果支持这样一种解释，即主要是低级视觉过程导致了直立和倒置刺激产生的偏差。
