Manual card sorting compared to automatic card presentation for assessing visual lobe size

Using a sample of 54 Hong Kong Chinese subjects a highly significant correlation was found between lobe area and search performance on a task where the stimulus presentation was controlled with a semi-automatic electro-mechanical ‘card changer’. By using the same stimulus material for determination of lobe size and search performance and by reducing the possibility of subjects using extreme search strategies, a 90s manual card sorting test was found to correlate significantly with the ‘card changer’ results and with lobe area. The good correlation with lobe area was obtained for a homogeneous group of subjects with respect to age and near acuity using a rapid and simple method of lobe area measurement. The visual lobe is a function of considerable importance for visual search and has been shown to be related to search performance in a variety of practical situations. It is suggested here that a card sorting task may be used to assess the relative extent of a person's visual lobe size for screening individuals involved in search tasks, or to assess the effects of training.