A Search Task to Assess Visual Lobe Size

Using a sample of 18 Cantonese Chinese subjects that covered a wide range of acuity scores and age, very high correlations were obtained between time taken on a simple card-sorting task and visual lobe dimensions. With subjects younger than 30 years of age and having good acuity, similar but not so highly significant correlations were found. Only one card-sorting session was required to produce useful data for between-subjects comparisons so that the card-sorting task may provide a simple, fast, and valid measure of a visual function of great importance to search performance. Also, a simple means of calculating visual lobe size from tachistoscopically presented stimulus material was tested and found to produce comparable results to those obtained using a more complex method of calculation involving data transformation.