Imagery and Action • Tool Use

A distinctively human talent is the construction and use of multi-part tools. The purpose of this work is to explore the competencies that may be responsible. During tool use, objects often change position, for example, when a wrench turns a bolt. Imagery may help people anticipate the displacements that result from tool use. The literature on imagery points to this possibility, but it has primarily explored the functions of imagery for recognizing objects and spatial arrays displaced by an experimenter. For imagery to enable tool use, it should also exhibit functions that specifically link the updating of an image to an individual’s actions. It should also help people imagine how similar actions with different tools yield different physical changes. Our claim is that people’s actions facilitate their imagery for object displacements, but that this facilitation depends on their mental model of the tool at hand.  For example, we have found that, after looking at a block and spool and closing their eyes, pulling the string shown in the figure below helps people imagine the block turning clockwise (as compared to not pulling the string).  However, it interferes with their ability to imagine the block turning counter-clockwise, unless they think the string is unwinding from the near-side of the spool.