Measurement and quantification of visual lobe shape characteristics

Previous work on visual lobes has shown marked irregularities in visual lobes, throwing doubt on the traditional assumptions about lobe shape. As very little research has been done on the shape aspect of visual lobe, the current study aimed to (a) propose a set of shape indices allowing easy and precise quantification of visual lobe shapes, (b) develop an application software for effective visual lobe shape mapping and computation of shape indices, and (c) map the visual lobes of a large number of subjects to determine shape characteristics for visual lobes. Visual Lobe Measurement System (VILOMS) software was developed and a set of 16 shape indices were calculated for 128 subjects using the software. The results demonstrated that lobe shapes were irregular with a low level of sphericity, moderately rough boundaries, horizontally elongated, and slightly asymmetric along vertical and horizontal axes. Correlations between the various indices were also investigated. Comparisons between the lobe shapes and the 24-sided approximated circle and ellipses showed that the lobe shapes were significantly different to the circles and the ellipses. Relevance to industry The current research developed a set of useful shape indices for measuring and quantifying visual lobe shapes. The visual lobe shape characteristics found with a large group of subjects indicated the general inadequacy of the commonly assumed oval or elliptical visual lobes previously employed in visual search modeling. The mean values of lobe shape indices obtained may lead to more accurate predictions of search performance. (c) 2006 Elsevier B.V. All rights reserved.