STRING EDITING ANALYSIS OF HUMAN VISUAL-SEARCH

Eye movement (EM) data were recorded for human subjects performing a v isual search task in a stereoscopic computer-generated three-dimension al scene. Each experimental run consisted of six presentations: three different object placements on a common background (quasi-natural scen e) were used and one of the placements was repeated three additional t imes. Raw EM searchpath data were linearized, fixation points were def ined via a fixation algorithm and, finally, strings of fixation region labels were obtained based upon a priori regionalization schemes. Use of string editing techniques allowed quantitative comparison of the s imilarity of various searchpaths. Analysis of the similarity of search paths for each subject, as well as across subjects, led us to conclude that presentation of repeated object placements caused each subject t o develop a partly self-consistent, but idiosyncratic searchpath based upon a spatial model for that placement pattern.