The Role Of Reaching In Action Recognition And Understanding

Problem of other minds is an ancient question that tries to answer how individual can grasp other's mental state by behavior.Currently,theory theory,rationality theory and simulation theory are three dominant approaches of problem of other minds.But,explicitly or implicitly,they all assume understanding intention of a given action requires both action and its context.Thus,those three theories ignored possibility that action as a bridge to other's mind directly.In this article,we suggest the relation between action and intention is deflationary,which means one can understand others mind by mere action.This proposal is based on the substantial researches showed that action kinematic influenced by goal,intention and context,which makes the action as an information wealthy object of perception.And,mirror neurons system linked together the action execution and action understanding system.Researchers noticed that observers' mirror neurons system is sensitive to the subtle differences of action.Recently,several studies showed the observer can discriminate other's action based on subtle differences in visual tasks,and understand those differences as corresponding mental state.In our study,we designed two experiments,and recruited over 50 college students as subjects in each experiment.In experiment 1,subjects need to judge whether the grasping was toward a small object(peanut,pencil)or big object(apple,glass)based on a 2-3 seconds pre-contact stage video without any context information or and post-contact information.The execution's arm can be fully seen or occluded by black clothes.In experiment 2,we further explored whether observer can understand the mental state accompany action execution by action alone.The video was similar to experiment 1,but the object behind screen was changed to small object(a porcelain wine cup filled with half cup of water,an aluminum foil wine cup filled full cup of water)and big object(a glass filled with half cup of water,a paper cup with full cup of water).The different state of filled water in each cup was designed to manipulate the difficult to spill out.Thus,in the experiment 2,the subject watched the video of grasping toward each object with different mental state(cautious,normal).Result of experiment 1 showed the occluded arm has a negative impact on action understanding,which means both palm and arm play a critical role in action understanding.Furthermore,experiment 2 showed grasping a small object was accompanied more gentle reaching stage than grasping an big object.Thus,each action is a specify object of perception,and support the argument of direct access to other's mind by action.