Rapid learning by walking observers wearing a reversing or inverting prism.

We measured the initial rapid learning of walking observers who wore an up-down inverting or left-right reversing prism. This prism-walking version of the 'mirror-drawing' experiment revealed that the learning curve as a function of the trial number was the same as that typically acquired from a traditional mirror-drawing experiment. We suggest that the initial short-term learning process involved in prism walking is similar to that in mirror drawing and is related to the high-level decision-making process involved in visuo-motor planning of actions with feedback from transformed vision.