The goal of sensation and perception is to guide us through our environment. We use visual information to avoid obstacles while walking around campus or driving on the highway. When it is completely dark, we avoid obstacles by touch. We feel our way by touching the obstacles in front of us. In this way, most of us can negotiate our own homes at night with the lights off by just using touch. We use auditory information to determine what people are saying and whether or not the phone is ringing. We use olfactory (smell) information to determine if we want to eat something or avoid any contact with it. We use information about temperature on our skin to determine if we want to wear a sweater or a T-shirt. Thus, perceiving what is around us guides us to action. We can define action as any motor activity. Action includes moving one’s eyes along the page of a book as well as a baseball player swinging his bat at incoming fastball. It includes turning your head when you hear the voice of a friend or a concert pianist’s fingers darting across her piano keyboard. Any movement we make can qualify as action. If that movement is directed by something we perceive in the environment, then we can see it is perception-guided action. In sum, one of the chief goals—if not the goal—itself is to guide functional action.
Our actions seem so easily controlled by our senses that it is easier to see how our senses control action by distorting our sensory input. Watch a few videos that illustrate how the distortion of visual input affects our actions and how we respond to these distortions.
The people in these videos are wearing goggles that make everything look off to the side by a few degrees. Their task is to play catch. In this video, the participants have just put the goggles on. Watch as they throw the beanbag off to the side where they see their partner in catch it. |
In this video, the participants have worn the goggles for a while, and they are much more successful in playing catch. They have adapted to the distortion, and they are better able to use vision to guide their throwing and catching. |
This adaptation has a price. Now the participants, including one of the authors, have taken off the goggles. For a few throws, the person stays adapted to the distortion caused by wearing the goggles, and now they are throwing the beanbag in the opposite direction than they did when they first put on the goggles. |