Fig. 1. Two competing models of how base maps may interact with cognitive maps when people draw sketch maps. In Panel A, the base map triggers specific recollections, which biases the resulting sketch map. In Panel B, recollections are not triggered based on the base map which merely serves to assist with the spatial referencing of cognitive maps. No significant base-map effect was found for the number of polygons drawn, the extent of the areas avoided or the degree to which those areas were avoided (see Table 3). However, a statistically significant association between tortuosity and paper size was found. Specifically, respondents drew more geographically-detailed sketch maps when given larger base maps. However, the number, extent and intensity of the avoided areas in those sketch maps did not systematically alter with base map changes. Fig. 2. Collective patterns of avoidance reported on A4 base maps (top left), A3 base maps (top right), and the difference between the two (bottom). Fig. 3. Collective patterns of avoidance reported on base maps with photographic imagery (top left) and OpenStreetMap imagery (top right), and the difference between the two (bottom). Figure S1. Base map supplied to respondents that used aerial photographic imagery. This map was printed in both A3 and A4 sizes. Figure S2. Base map supplied to respondents that used OpenStreetMap imagery. This map was printed in both A3 and Adé4 sizes. Table S2. Examples of each of the sketch map categories.
