Where do we look when we count? The role of eye movements in enumeration

Two experiments addressed the coupling between eye movements and the cognitive processes underlying enumeration. Experiment 1 compared eye movements in a counting task with those in a "look" task, in which subjects were told to look at each dot in a pattern once and only once. Experiment 2 presented the same dot patterns to every subject twice, to measure the consistency with which dots were fixated between and within subjects. In both experiments, the number of fixations increased linearly with the number of objects to be enumerated, consistent with tight coupling between eye movements and enumeration. However, analyses of fixation locations showed that subjects tended to look at dots in dense, central regions of the display and tended not to look at dots in sparse, peripheral regions of the display, suggesting a looser coupling between eye movements and enumeration. Thus, the eyes do not mirror the enumeration process very directly.