Modelling Experiential and Task Effects on Attentional Processes in Symmetry Detection

Abstract

The effects of attention and scanning strategies on symmetry detection have been discussed by several investigators, Locher et al. (1993) and Wenderoth (1994) being good examples. Wenderoth showed that the salience of vertical and horizontal symmetry can be manipulated by varying the range of stimuli presented, and attributes this to effects on the scanning or attentional strategies adopted by subjects. Locher et al demonstrated that scanning patterns on symmetrical displays could be manipulated by instructions and task requirements. In this paper, we look at the effects of task requirements and experience on the distribution of eye movements and fixations on symmetrical dot patterns. It is possible to link eye movements and fixations to attention by creating tunnel vision stimulus conditions, using fixation contingent displays or simply by using large stimulus patterns. In our studies, we are using large patterns together with control conditions in which the same patterns are presented at a size small enough not to require eye movements. The underlying assumption is that if we can reproduce the same order of reaction times and errors in both contexts, then the overt eye movements and fixations on the large patterns may be valid indices of small, covert attentional shifts that occur naturally on the small versions of the patterns, but which cannot otherwise be observed. We report data from one participant with five years experience viewing, constructing and manipulating symmetrical patterns and one participant without such experience. Future work will compare the eye movements and fixations of architects, and designers and those of inexperienced controls.