[The influence of geometric visual illusions on saccadic eye movements].
BACKGROUND
The aim of this study was to investigate whether visually perceived length differences of Mueller-Lyer figures result in amplitude differences of saccadic eye movements along the figures.


METHODS
Video recordings of eye movements were obtained from 35 healthy volunteers (aged 18 - 30 years) when scanning the endpoints of Mueller-Lyer targets.


RESULTS
Saccades between the ends of lines with inward-pointing arrowheads had significantly greater amplitudes than saccades between the ends of lines with outward-pointing arrowheads. This bias was observed for both horizontal and vertical target orientations, and was maintained with a smaller amplitude, after fixation periods were extended from 1 s to 4 s.


CONCLUSIONS
Changes in length perception by visual illusions correspond with changes in the amplitude of saccadic eye movements. Therefore, recordings of saccadic eye movements offer the opportunity to assess changes in visual object perception based on changes of central image processing at the cortical level.
Tegetmeyer
H
H
Klinik und Poliklinik für Augenheilkunde, Universität Leipzig. tegeth@medizin.uni-leipzig.de
Wenger
A
A
D000293:Adolescent; D000328:Adult; D005260:Female; D005403:Fixation, Ocular; D006801:Humans; D008297:Male; D009903:Optical Illusions; D009949:Orientation; D010364:Pattern Recognition, Visual; D011601:Psychophysics; D012016:Reference Values; D012438:Saccades; D012858:Size Perception