Cite as:
Hamburger K, Baier F, Spillmann L, 2012, "The tilted Hermann grid illusion: ‘Illusory spots’ versus ‘phantom bands’" Perception 41(2) 239 – 242
Download citation data in RIS format

Short and sweet
The tilted Hermann grid illusion: ‘Illusory spots’ versus ‘phantom bands’

Kai Hamburger, Franziska Baier, Lothar Spillmann

Abstract. The Hermann grid illusion became a cause célèbre, when it was reported that small figural changes from straight to curved bars abolish the dark illusory spots. We demonstrate that this is not an all-or-none effect; rather, the visual system tolerates some tilt/curviness. We transformed straight and curved Hermann grids to rhombic Motokawa grids by gradually tilting the horizontal bars. Initially, we observed only dark illusory spots, then dark spots combined with phantom bands traversing the rhomb along the minor axis, and finally dark phantom bands only. This shows that two kinds of illusions can coexist in the same grid pattern.

 Full-text PDF size: 414 Kb

 References  9 references, 7 with DOI links ()