Hack 67. Objects Ask to Be Used (2)
Effects of object affordances have been found in experiments: Tucker and Ellis1 asked subjects to press a button with their left or right hand, to indicate whether a picture of an object was the right way up or inverted. Even though subjects were not thinking about the action they would use for that object, it had an effect. If they saw a cup with a handle pointing toward the rightevoking a right-hand graspthey were faster to react if their response also happened to require a right-hand response. That is, the reaction time improved if the hand used for the button press coincided with the hand that would be used for interacting with the object. This is called a compatibility effect. (The Simon Effect [Hack #56] shows that reaction times improve when stimuli and response match in the more general case. What’s happening here is that the stimulus includes not just what you perceive directly, but what affordances you can perceive too.)
The graspability of objects can affect judgments, even when people are not making any kind of movement. de’Sperati and Stucchi2 asked people to judge which way a moving screwdriver was rotating on a computer screen. People were slower to make a judgment if the handle were in a position that would involve an awkward grasping movement with their dominant hand. That is, although they had no intention to move, their own movement system was affecting their perceptual judgment.
6.7.2. How It Works
Brain imaging has helped us to understand what is happening when we see action-relevant objects. Grèzes and Decety3 looked at which brain areas are active when people do the Tucker and Ellis judgment task. Bits of their brain become active, like the supplementary motor area and the cerebellum, which are also involved in making real movements. In related research in monkeys, cells have also been discovered that respond both when the monkey sees a particular object and also when it observes the type of action that object would require.
People with damage to their frontal lobes sometimes have problems suppressing the tendency to act upon objects. They might automatically pick up a cup or a pair of glasses, without actually wishing to do so (or even when they’re told not to). It is thought that we all share these same tendencies, but with our intact frontal lobes, we are better at stopping ourselves from acting them out. (Frontal patients can also have trouble suppressing other impulses; for instance, some become compulsive gamblers.)
Taken from : Mind Hacks
