Does drawing skill relate to better memory of local or global object structure?

摘要

An accurate drawing must respect the overall shape as well as the relative positions of the depicted object?￠a??a?￠s features, which define its structure. We previously found that participants who are more skilled at drawing are also better at integrating structural information across eye-movements in a possible vs impossible objects task (Perdreau & Cavanagh, 2013). This ability may be due to an internal representation that is robust to the disruptions from the many eye-movements made between the object and the drawing. It remains unclear, though, whether drawing accuracy relates to the storage of the entire object?￠a??a?￠s structure or only of the local features relevant to the current drawing position. To test these alternatives, we designed an interactive pen tablet experiment coupled with a delayed change detection task. A simple polygonal shape was displayed on a screen and participants had to copy it on a pen tablet on which they could see their drawing. At an unpredictable moment during the copying process, the drawing and the original shape were blanked out. After a fixed delay of 900 ms, the drawing reappeared with a possible modification consisting in the displacement of one of its vertices chosen relative to the last drawn point (n, n-1, n-2 or n-4). Participants had to report whether a modification in their drawing had occurred or not (2-AFC). Our results showed that participants who were more skilled at drawing were also better at detecting changes but only when these occurred either at the n (current) or at the n-1 position. This suggests that participants who were more skilled at drawing depended more on visual memory for the information relevant to the current drawing position and less on the memory of the object?￠a??a?￠s global structure.