Fig. 4
Comparison of object location and size across conditions. a Top—the mean X and Y distance between object centroids of the different drawing conditions (Delayed Recall, Immediate Recall, Image Drawing) and object centroids in the original image. Object centroids were determined from ellipses placed around each drawn object by AMT workers. The y-axes represent the distance as the proportion of the x-direction (or y-direction) pixel distance between centroids and the image pixel width (or height). Bottom—the mean ellipsis width and height differences between objects in each drawing condition and the objects in the original images. Y axis values represent width and height differences as a proportion of image width and height, respectively. Each dot represents each of the 60 images used in the experiments, and lines connect the same image across conditions. Significance in Wilcoxon rank-sum tests between conditions is indicated with horizontal lines at the top (Bonferroni-corrected p < 0.0167). b Example maps of the average ellipse encompassing the most commonly drawn objects in four of the images. Solid ellipses indicate the average object location in the Delayed Recall drawings, whereas dashed ellipses indicate the average object location in the Image Drawings. Participants in both conditions drew objects in the correct locations and at the right sizes; e.g., in the bathroom, putting the mirror in the upper left, the cabinet in the upper middle, the shower on the right, and the sink on the bottom left. This shows that participants drawing from memory had spatially accurate memory representations, drawing objects in the correct places and correct sizes from objects they had seen in images 11-min earlier
