Are participants in these experiments mentally rotating the whole stimulus, or are they looking only at certain parts? To answer this question Lynn Cooper (1975) performed studies that (ดูไม่ออก) presented participants with irregular polygons such as those shown in Figure 8.6. The polygons were formed by connecting a random scattered number of points, with more complete polygons resulting from a greater number of points. Participants were first trained a discriminate between original and mirror image reflections of the polygons. Next, …(ดูไม่ออก) were shown either the original polygons …(ดูไม่ออก) reflections at different angles of rotation …(ดูไม่ออก) at the different angles of rotation …(ดูไม่ออก) were asked to determine whether the …(ดูไม่ออก) whether the object …(ดูไม่ออก) depicted was the original or a reflection of the original.