Schiller P H, Carvey C E, 2005, "The Hermann grid illusion revisited" Perception 34(11) 1375 – 1397
Download citation data in RIS format
The Hermann grid illusion revisited
Peter H Schiller, Christina E Carvey
Received 12 October 2004, in revised form 12 January 2005; published online 23 September 2005
Abstract. The Hermann grid illusion consists of smudges perceived at the intersections of a white grid presented on a black background. In 1960 the effect was first explained by a theory advanced by Baumgartner suggesting the illusory effect is due to differences in the discharge characteristics of retinal ganglion cells when their receptive fields fall along the intersections versus when they fall along non-intersecting regions of the grid. Since then, others have claimed that this theory might not be adequate, suggesting that a model based on cortical mechanisms is necessary [Lingelbach et al, 1985 Perception 14(1) A7; Spillmann, 1994 Perception 23 691 – 708; Geier et al, 2004 Perception 33 Supplement, 53; Westheimer, 2004 Vision Research 44 2457 – 2465]. We present in this paper the following evidence to show that the retinal ganglion cell theory is untenable: (i) varying the makeup of the grid in a manner that does not materially affect the putative differential responses of the ganglion cells can reduce or eliminate the illusory effect; (ii) varying the grid such as to affect the putative differential responses of the ganglion cells does not eliminate the illusory effect; and (iii) the actual spatial layout of the retinal ganglion cell receptive fields is other than that assumed by the theory. To account for the Hermann grid illusion we propose an alternative theory according to which the illusory effect is brought about by the manner in which S1 type simple cells (as defined by Schiller et al, 1976 Journal of Neurophysiology 39 1320 – 1333) in primary visual cortex respond to the grid. This theory adequately handles many of the facts delineated in this paper.
Full-text PDF size: 379 Kb
References 80 references, 34 with DOI links ()
Your computer (IP address: 22.214.171.124) has not been recognised as being on a network authorised to view the full text or references of this article. If you are a member of a university library that has a subscription to the journal, please contact your serials librarian (subscriptions information).