Measures of the Complexity of Random Black and White and Coloured Stimuli

The construction of black and white random-line stimuli having internal intersections, and a set of bi-coloured stimuli derived from these, is described. The number of internal intersections as an index of subjective complexity is shown to be highly valid for both sets, and the number-of-perimetric-turns variable is also shown to have a high correlation with judged complexity.