Calibration to tool use during visually-guided reaching.

In studying human perception and performance researchers must understand how the body schema is modified to accurately represent one's capabilities when tools are used, as humans use tools that alter their capabilities frequently. The present work tested the idea that calibration is responsible for modifying an embodied action schema during tool use. We investigated calibration in the context of manual activity in near space through a behavioral measure. Participants made blind reaches to various visual distances in pre- and post-test phases using a short tool that did not extend their reach. During an intervening calibration phase they received visual feedback about the accuracy of their reaches, with half of the participants reaching with a tool that extended their reach by 30cm. Results indicated both groups showed calibration appropriate to the type of tool that they used during the calibration phase, and this calibration carried over to reaches made in the post-test. These results inform discussions on the proposed embodied action schema and have applications to virtual reality, specifically the development of self-avatars.