Verfaillie Karl, Daems Anja
Laboratory of Experimental Psychology, Brain and Cognition, Faculty of Psychology and Educational Sciences, KU Leuven, Leuven, Belgium.
Front Psychol. 2020 Mar 10;11:393. doi: 10.3389/fpsyg.2020.00393. eCollection 2020.
The proficiency of human observers to identify body postures is examined in three experiments. We use a posture decision task in which participants are primed with either anatomically possible or impossible postures (in the latter case the upper and lower body face in opposite directions). In a long-term priming paradigm (i.e., in an initial priming block of trials and a subsequent test phase several minutes later), we manipulate the relation between priming and test postures with respect to the identity of the person in the body postures (Experiment 1), the prototypicality of the depth orientations (Experiment 2), and the variability of the priming orientations (Experiment 3). Reaction time to the test postures is the main dependent variable. In Experiment 1 it is found that priming of postures does not depend on the exact visual appearance of the actor (either same priming and test female or male figure or different figures), supporting the hypothesis that posture priming primarily is determined by the spatial relations between the body parts and much less by characteristics of the person involved. Long-term priming in our paradigm apparently is based on the reactivation of high-level posture representations that make abstraction of the identity of the human figure. In Experiment 2 we observe that privileged or prototypical orientations (e.g., 3/4 views) do not affect long-term priming of body postures. In Experiment 3, we find that increasing or decreasing the variability between the priming and test figures influences reaction time performance. Collectively, these results provide a better understanding of the flexibility (e.g., invariant to identity) and limits (e.g., depending on depth orientation) of the processes supporting human posture recognition.
在三个实验中考察了人类观察者识别身体姿势的能力。我们使用了一种姿势判断任务，在该任务中，向参与者呈现解剖学上可能或不可能的姿势（在后一种情况下，上半身和下半身朝向相反方向）。在长期启动范式中（即在初始启动试验块和几分钟后的后续测试阶段），我们根据身体姿势中人物的身份（实验1）、深度方向的典型性（实验2）以及启动方向的变异性（实验3）来操纵启动姿势和测试姿势之间的关系。对测试姿势的反应时间是主要的因变量。在实验1中发现，姿势启动并不取决于演员的确切视觉外观（启动和测试的是同一女性或男性形象，或者是不同形象），这支持了以下假设：姿势启动主要由身体各部分之间的空间关系决定，而较少由所涉及人物的特征决定。我们范式中的长期启动显然基于高级姿势表征的重新激活，这些表征对人物形象的身份进行了抽象。在实验2中，我们观察到特权或典型方向（例如3/4视图）不会影响身体姿势的长期启动。在实验3中，我们发现增加或减少启动和测试形象之间的变异性会影响反应时间表现。总的来说，这些结果有助于更好地理解支持人类姿势识别的过程的灵活性（例如，对身份不变）和局限性（例如，取决于深度方向）。
