Wang Li, Yang Xiaoying, Shi Jinfu, Jiang Yi
State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, 16 Lincui Road, Beijing 100101, PR China.
Neuroimage. 2014 Jan 1;84:217-24. doi: 10.1016/j.neuroimage.2013.08.041. Epub 2013 Aug 28.
Most vertebrates, humans included, have a primitive visual system extremely sensitive to the motion of biological entities. Most previous studies have examined the global aspects of biological motion perception, but local motion processing has received much less attention. Here we provide direct psychophysical and electrophysiological evidence that human observers are intrinsically tuned to the characteristics of local biological motion cues independent of global configuration. Using a modified central cueing paradigm, we show that observers involuntarily orient their attention towards the walking direction of feet motion sequences, which triggers an early directing attention negativity (EDAN) in the occipito-parietal region 100-160ms after the stimulus onset. Notably, such effects are sensitive to the orientation of the local cues and are independent of whether the observers are aware of the biological nature of the motion. Our findings unambiguously demonstrate the automatic processing of local biological motion without explicit recognition. More importantly, with the discovery that local biological motion signals modulate attention, we highlight the functional importance of such processing in the brain.
包括人类在内的大多数脊椎动物都拥有一个对生物实体运动极其敏感的原始视觉系统。此前的大多数研究都考察了生物运动感知的整体方面，但局部运动处理受到的关注要少得多。在这里，我们提供了直接的心理物理学和电生理学证据，表明人类观察者内在地适应于局部生物运动线索的特征，而与整体构型无关。使用一种改良的中央提示范式，我们表明观察者会不由自主地将注意力导向脚部运动序列的行走方向，这会在刺激开始后100 - 160毫秒在枕顶叶区域触发早期定向注意负波（EDAN）。值得注意的是，这种效应对局部线索的方向敏感，并且与观察者是否意识到运动的生物性质无关。我们的发现明确地证明了局部生物运动的自动处理，无需明确识别。更重要的是，随着发现局部生物运动信号调节注意力，我们强调了这种处理在大脑中的功能重要性。
