Editorial: Taking a hands-on approach: current perspectives on the effect of hand position on vision

Preventing action slows down performance in perceptual judgment

Action and vision are known to be tightly coupled with each other. In a previous study, we found that repeatedly grasping an object without any visual feedback might result in a perceptual aftereffect when the object was visually presented in the context of a perceptual judgement task. In this study, we explored whether and how such an effect could be modulated by presenting the object behind a transparent barrier. Our conjecture was that if perceptual judgment relies, in part at least, on the same processes and representations as those involved in action, then one should expect to find a slowdown in judgment performance when the target object looks to be out of reach. And this was what we actually found. This indicates that not only acting upon an object but also being prevented from acting upon it can affect how the object is perceptually judged.

How action performance affects object perception

How deep is the linkage between action and perception? Much is known about how object perception impacts on action performance, much less about how action performance affects object perception. Does action performance affect perceptual judgment on object features such as shape and orientation? Answering these questions was the aim of the present study. Participants were asked to reach and grasp a handled mug without any visual feedback before judging whether a visually presented mug was handled or not. Performing repeatedly a grasping action resulted in a perceptual categorization aftereffect as measured by a slowdown in the judgment on a handled mug. We suggest that what people are doing may impact on their perceptual judgments on the surrounding things.