, Volume 35, Issue 4, pp 313-318

Structural and cognitive components in the Müller-Lyer illusion assessed via Cyclopean presentation


Several levels of visual information processing contribute to the formation of visual geometric illusions. The present experiment attempted to separate the relative contributions of structural (physiologically based) and strategy (cognitively based) mechanisms in the formation of the Müller-Lyer illusion. A novel experimental procedure that combined Cyclopean stimulus presentation and illusion decrement was employed. The results indicated that approximately 47% of the observed illusion magnitude can be attributed to the involvement of structural factors, a result consistent with other studies that have used different experimental techniques to explore the same issue.

This research was supported by grants from the Natural Sciences and Engineering Research Council of Canada and represents an equal and shared contribution of both authors.