Abstract
From the finding that the absolute threshold for rotational movement was significantly lower for a field of randomly, as opposed to regularly, distributed black and white squares it was hypothesized that only in the case of high selective information-content fields would there be an inverse relationship between size of elements and the movement threshold. Movement thresholds, obtained for random and regular displays containing different sizes of internal element, confirmed the crucial role of selective information in determining the movement threshold but did not support the predicted size effect. This apparent paradox may be explained by the reduced confidence which Ss experience when judging the movement of random displays.