Viewpoint-dependent Priming Effects in the Perception of Human Actions and Body Postures

Anja Daems, Karl Verfaillie
1999 Visual Cognition  
The identification of human actions and body postures viewed from different viewpoints was examined in four long-term priming experiments with static pictures of a human model. In Experiments 1 and 2 participants had to name or describe the pictures, and in Experiments 3 and 4 participants had to decide whether the pictures showed a possible or impossible body pose. Reliable priming effects were obtained only when priming and primed action or pose shared the same in-depth orientation
more » ... s 1 and 4) and left-right reflection (Experiments 2 and 3). Having seen the same action or pose in a different orientation did not reliably facilitate identification performance later on. Also, there was no priming for poses that are impossible to perform with a human body, not even when an identical same-view prime was used. These findings suggest that the stored representations that mediate the identification of human actions and postures are viewpoint specific. One kind of stimulus that virtually all human observers encounter numerous times in their lives is other human beings, engaged in many different actions, resulting in an even greater variety of body postures. Identifying these actions and body postures must therefore be a major task of the human visual system. This task is not straightforward, though. Depending on the orientation and position of the acting body relative to the observer, different instances of a Requests for reprints should be addressed to A. Daems,
doi:10.1080/135062899394894 fatcat:jxq4pmoyezd3ljqk4pdjvvyt3u