Wuerger Sophie M, Crocker-Buque Alexander, Meyer Georg F
Department of Experimental Psychology, University of Liverpool, Liverpool, UK.
Seeing Perceiving. 2012;25(1):15-28. doi: 10.1163/187847611X620892.
Biological motion is usually associated with highly correlated sensory signals from more than one modality: an approaching human walker will not only have a visual representation, namely an increase in the retinal size of the walker's image, but also a synchronous auditory signal since the walker's footsteps will grow louder. We investigated whether the multisensorial processing of biological motion is subject to different constraints than ecologically invalid motion. Observers were presented with a visual point-light walker and/or synchronised auditory footsteps; the walker was either approaching the observer (looming motion) or walking away (receding motion). A scrambled point-light walker served as a control. Observers were asked to detect the walker's motion as quickly and as accurately as possible. In Experiment 1 we tested whether the reaction time advantage due to redundant information in the auditory and visual modality is specific for biological motion. We found no evidence for such an effect: the reaction time reduction was accounted for by statistical facilitation for both biological and scrambled motion. In Experiment 2, we dissociated the auditory and visual information and tested whether inconsistent motion directions across the auditory and visual modality yield longer reaction times in comparison to consistent motion directions. Here we find an effect specific to biological motion: motion incongruency leads to longer reaction times only when the visual walker is intact and recognisable as a human figure. If the figure of the walker is abolished by scrambling, motion incongruency has no effect on the speed of the observers' judgments. In conjunction with Experiment 1 this suggests that conflicting auditory-visual motion information of an intact human walker leads to interference and thereby delaying the response.
一个正在靠近的行人不仅会有视觉呈现，即行人图像在视网膜上的尺寸增大，还会有同步的听觉信号，因为行人的脚步声会越来越大。我们研究了生物运动的多感官处理是否受到与生态无效运动不同的限制。向观察者呈现一个视觉点光行人模型和/或同步的听觉脚步声；行人模型要么靠近观察者（逼近运动），要么远离（后退运动）。一个打乱的点光行人模型用作对照。要求观察者尽可能快速、准确地检测出行人模型的运动。在实验1中，我们测试了由于听觉和视觉模态中的冗余信息而产生的反应时优势是否特定于生物运动。我们没有发现这种效应的证据：反应时的减少是由生物运动和打乱运动的统计促进作用所解释的。在实验2中，我们分离了听觉和视觉信息，并测试了与一致的运动方向相比，听觉和视觉模态之间不一致的运动方向是否会产生更长的反应时。在这里，我们发现了一种特定于生物运动的效应：只有当视觉行人模型完整且可识别为人形时，运动不一致才会导致更长的反应时。如果通过打乱消除行人模型的形状，运动不一致对观察者的判断速度没有影响。结合实验1，这表明完整行人模型的听觉 - 视觉运动信息冲突会导致干扰，从而延迟反应。
