Imagery and Action • Adaptation and Recalibration

People learn to use tools by changing the coupling between their motor actions and the expected consequences. For example, after using a computer mouse for a while, people learn to anticipate the upward movement of the cursor when they push their hand forward on the desk. This is often called, “perceptual-motor skill acquisition.” This line of work asks how people manage to learn a new coupling or skill that they can flexibly change when they switch from one tool to another. The work relies on adaptation paradigms (e.g., with prism glasses) and recalibration paradigms (e.g., walking the wrong direction on a moving walkway). One finding has been that the timing of an action exerts a strong role in producing recalibration effects.  For example, after recalibration, moving slowly expresses greater effects of recalibration than moving at the same speed used during the recalibration period, and monotonically greater effects than moving even more quickly.

A second emerging finding is that people’s mental models (or lack thereof) determine when there is skill acquisition instead of perceptual adaptation. For example, we have asked subjects to use a tool to point at a location on a screen.  During this time, they wear prisms.  Half of the subjects know what the tool looks like and half do not.  After the period of adaptation, people remove the glasses and let go of the tool.  Their task is to point at an object on a screen.  People who knew the structure of the tool exhibit greater after-effects from the adaptation period than the people did not know the structure of the tool.  The people who did not know the structure of the tool evidently attributed the prism's effect to the tool.  It is an interesting question how the brain shunts adaptation to a tool when there is no information specifying the tool, but shunts adaptation to visual-motor coupling when there is information specifying the shape of the tool.