Abstract
When people observe an action, how do they predict its outcome? Knoblich and Flach (2001) proposed that people simulate performing observed actions to predict their effects. They found that people were more accurate in predicting the outcome of an action when viewing videos of themselves than when viewing videos of another person. Presumably, when people watched videos of themselves, the system that performed the original action also simulated the action during perception and this match yielded more accurate predictions. We sought to investigate and extend this simulation hypothesis. We filmed participants (N=13) throwing Velcro balls at two targets from an allocentric (profile) viewpoint and an egocentric (over-the-shoulder) viewpoint. Participants made throws with their dominant and non-dominant hands. We subsequently asked participants to predict the trajectory of their own throws and another participant’s throws as they watched videos spanning the onset of the throwing motion to the last frame before release. Participants made more accurate predictions when they viewed videos taken from an allocentric viewpoint compared to an egocentric viewpoint regardless of whether they watched their own throws or another’s throws. Interestingly, participants’ predictions were also more accurate when they viewed a throw performed with the dominant hand than with the non-dominant hand, but only when they observed their own actions. This result provides new support for the simulation hypothesis: participants were more accurate in predicting throws they made with their own dominant hand because they used the same system to both generate and simulate these actions. The fact that participants were no more accurate in predicting the outcome of throws made with their non-dominant hand than they were in predicting throws made by another actor also suggests that people automatically make predictions that guide perception based on dominant hand simulations, regardless of which hand they observe.
Meeting abstract presented at VSS 2012