Simple measures of visual-lobe size and search performance.

The objectives of this study were to simplify lobe-size calculation; and to test a simple card-sorting task as a measure of lobe size. A simple method of calculating lobe dimensions from tachistoscopically presented stimuli was found to give results that were comparable to a more complex method using data transformation. A 1 min card-sorting test using only one target against a homogeneous background was shown to be sensitive to subject differences in visual lobe area. With the type of sorting-test material proposed, the whole testing procedure would, at the most, require a 1 min practice period followed by a 1 min test trial. Near foveal acuity was significantly related to horizontal lobe dimensions and to some measures of card-sorting performance. The study showed that a card-sorting task provided a rapid and simple means of estimating relative visual-lobe size.