A temporal window for estimating surface brightness in the Craik-O'Brien-Cornsweet effect

Abstract

The central edge of an opposing pair of luminance gradients (COC edge) makes adjoining regions with identical luminance appear to be different. This brightness illusion, called the Craik-O'Brien-Cornsweet effect (COCe), can be explained by low-level spatial filtering mechanisms (Dakin and Bex, 2003). Also, the COCe is greatly reduced when the stimulus lacks a frame element surrounding the COC edge (Purves et al., 1999). This indicates that the COCe can be modulated by extra contextual cues that are related to ideas about lighting priors. In this study, we examined whether processing for contextual modulation could be independent of the main COCe processing mediated by the filtering mechanism. We displayed the COC edge and frame element at physically different times. Then, while varying the onset asynchrony between them and changing the luminance contrast of the frame element, we measured the size of the COCe. We found that the COCe was observed in the temporal range of around 600–800 ms centered at the 0 ms (from around −400 to 400 ms in stimulus onset asynchrony), which was much larger than the range of typical visual persistency. More importantly, this temporal range did not change significantly regardless of differences in the luminance contrast of the frame element (5–100%), in the durations of COC edge and/or the frame element (50 or 200 ms), in the display condition (interocular or binocular), and in the type of lines constituting the frame element (solid or illusory lines). Results suggest that the visual system can bind the COC edge and frame element with a temporal window of ~1 s to estimate surface brightness. Information from the basic filtering mechanism and information of contextual cue are separately processed and are linked afterwards.

The Gold Standard Paradox in Digital Image Analysis: Manual Versus Automated Scoring as Ground Truth

“…Adjacent objects are perceived as having different brightness based on variations in staining intensity, when in fact they are the same (Figure 1, D). [24][25][26] This illusion may influence a pathologist's assessment of the staining of adjacent cells, where staining must be assessed for both the cytoplasm (middle) and membrane (edge); dissimilarities of staining intensity at the membrane may lead to misinterpretation of cytoplasmic staining intensity.…”

Proceedings of the 2017 National Toxicology Program Satellite Symposium

“…In this illusion, the brightness change along the edge in the middle influences the perception of both surfaces to the left and right of the middle having different brightness when in fact the majority is of the same brightness. To confirm, cover the middle of the image to see that the majority of the area is the same intensity or shade of gray (Kurki et al 2009; Purves, Shimpi, and Lotto 1999; Masuda et al 2014; Aeffner et al 2017). Herman grid illusion (H) is a display of lateral inhibition (LI), which is a perceived increase of contrast and sharpness (Aaen-Stockdale 2007).…”

“…The Craik-O'Brien-Cornsweet illusion demonstrates the human's perception of surfaces based on the optical characteristics of their edges (Fibonacci, 2007; Figure 4G). Adjacent objects appear to have a different brightness caused by a variation in staining intensity at the interface only, when in fact these adjacent objects are of the same staining intensity for the majority of the surface (Kurki et al , 2009, Purves, Shimpi and Lotto, 1999, Masuda et al , 2014). This effect is likely at play when it has been reported that the same membranous staining intensity is perceived as being different, depending upon if it is evaluated next to cytoplasm with staining or devoid of staining (Conway et al , 2008).…”