Eye movements of large populations: II. Deriving regions of interest, coverage, and similarity using fixation maps.

The analysis of eye movement traces (i.e., the patterns of fixations in a search) is more complex than that of such parameters as mean fixation duration, and as a result, previous attempts have focused on a qualitative appraisal of the form of an eye movement trace. In this paper, the concept of the fixation map is introduced. Its application to the quantification of similarity of traces and the degree of coverage by fixations of a visual stimulus is discussed. The ability of fixation maps to aid in the understanding and communication of large numbers of eye movement traces is examined.