Human Perception of Homogeneous Dot Patterns

Experiments were conducted to ascertain human performance at clustering relatively homogeneous dot patterns. Two methods for clustering a rectangular array of dots into two halves were studied: one increased the separation between the left and right halves, and the other increased the density of one of the halves. Significant effects were found for array height on the perception of ‘separation’ patterns, and for overall dot density on the ‘density’ patterns. The results indicate that global properties of dot patterns affect the immediate perception of clusters, and consequently attempts to simulate human perception must incorporate the processing of such global properties. The results also indicate that different perceptual processes operate on dot proximity in perceiving the two kinds of pattern. It is suggested that these processes are in fact complementary: one detects perceptual edges, while the other groups areas of similar dot density.