Arbitrary eye movement strategy in global-local processing experiments

Background and Aim : Perceptual organization is one of mostly debated issues in visual perception. We all process global features faster than local details, called Global Precedence . Researches have shown that whatever stimulus eccentricity getting more distance from fovea, the perception of local details becomes harder. Researchers usually found this result when gaze point was fixed on the center of field of view and the stimulus location was manually adjusted.Methods : Our question is In process of global and local features, what is eye movement strategy to choose arbitrary eccentricity when the gaze point was not restricted to a particular fixation point . We design two experiments in two different paradigms: Matching and Similarity Judgment. We setup an EYELINKII™, 1000Hz to perform these two tasks with fifteen participants.Results : We found that the global precedence was confirmed by these two experiments. Also, we interestingly observed a high average of arbitrary eccentricity in global trials, in compared with local trials. Despite, the number of fixations were meaningfully more in local trials.Conclusion : Naturally, higher arbitrary eccentricity is preferred to percept global features.

Keywords:

perceptual organization , global precedence , arbitrary eccentricity , eye movement strategy