An experimental contribution to the problem of apparent reality

Certain two-dimensional figures acquire a character of relief and reality when oriented obliquely to the observer and viewed monocularly. The experiments were made with two types of figure—a simple straight line, and more complex patterns of lines. The results indicate that the character of reality gradually increases as the experimental conditions become more favourable. The conditions found to be most favourable are dissimilarities of size, brightness, microstructure, shape, perspective clues, between figure and ground.

When the segregating factors are operating, the figure becomes independent of the paper and takes up its own orientation in space. In the case of the simple line, this orientation may be frontal, but more usually the orientation of the background is taken into account, the resulting structural organization being that of a “needle” projecting from the background. The reality is greatest when the orientation of the background is such that the “needle” appears to be perpendicular to the ground. The complex figures used in the experiments were perspective designs of parallelepipeds. Again, the oblique position of the design associated Tvith the greatest degree of reality of the tridimensional object is that which permits the figure to be seen as projecting perpendicularly from its background.