Experimental Studies of a Perceptual Anomaly. III. The Testing of an Explanatory Theory

Abstract

This is the third of a series of articles reporting an investigation of the block design rotation effect. This effect is shown by some patients when they are doing the Kohs' Blocks Test, which is known in other forms as the Block Design Test. In this test the subject has to reproduce patterns with the aid of diversely coloured one-inch cubes. It was observed that some patients, while they reproduced these patterns correctly, left their blocks in an obviously rotated position, apparently with no idea that anything was amiss (see Illus tration i). Such rotation can often be as great as 45°.