Eye Movements and Scene Perception

The present thesis reports two experiments and a meta§analysis on eye movements during scene perception.§Experiment 1 revealed that saccade amplitude is§directly proportional to image size, but the course§of saccade amplitudes over viewing time is§unaffected. Together with a meta analysis over image§perception studies, this strongly suggests that§saccade amplitude is predominantly controlled by§stimulus size. Other factors such as image type,§viewing task, or tracking equipment are of§subordinate importance. Experiment 2 assessed the§influence of viewing task and stimulus repetition.§The results show that the viewing strategy adopted to§solve a task is crucial, as the found patterns cannot§be explained by memory load effects alone. Stimulus§repetition influenced oculomotor measures in ways§that refer to effects of visuo-spatial memory. Both§experiments underline that several aspects of§oculomotor behaviour are not constant over time; the§behaviour seems to be of a different quality during§the first one or two seconds. In sum, the results§indicate that many elementary parameters are more§important than previously thought, pertaining to§theoretical as well as methodological issues.