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

Masuda A, Watanabe J, Terao M, Yagi A, Maruya K - Front Hum Neurosci (2014)

Bottom Line: Also, the COCe is greatly reduced when the stimulus lacks a frame element surrounding the COC edge (Purves et al., 1999).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).

View Article: PubMed Central - PubMed

Affiliation: Department of Integrated Psychological Science, Kwansei Gakuin University Nishinomiya, Japan.

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.

No MeSH data available.


Related in: MedlinePlus

Results of experiment 1 (durations of COC edge and frame element were 200 ms). The description of each graph is the same as in the caption of Figure 5.
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Figure 6: Results of experiment 1 (durations of COC edge and frame element were 200 ms). The description of each graph is the same as in the caption of Figure 5.

Mentions: The apparent brightness was estimated for each condition by calculating the PSEs. When the COCe is observed, the PSE is yielded at a positive contrast value, and a larger PSE indicates that a stronger COCe occurred. In all conditions, the dynamics of the PSE against SOA conditions (COCe dynamics) draws a bell-shape (Figures 5A, 6A for 50 ms durations of the COC edge and frame element and for 200 ms durations, respectively). The maximum PSE was around 15% (15.4, 13.2, and 21.6% for AM, YM, and TF, respectively). In the control condition, the estimated PSEs were around 3% (2.7, 1.4, and 4.2% for AM, YM, and TF, respectively). The maximum COCe size increased as the luminance contrast of the frame element increased when the durations of COC edge and frame element were 50 ms (Figure 5B) and 200 ms (Figure 6B). The COCe decreased as the absolute value of SOA increased. The COCe at largest SOAs (±400 ms) was not significantly different from the COCe in the control condition among all contrast and duration conditions (Figures 5C,D, 6C,D). In most conditions, the range of the SOA, in which the presence of the frame element was significantly effective (hereafter called the SOA range; see also Figure 2) was between −300 and 300 ms, except for several conditions where the frame duration was 50 ms and the contrast was low (< = 10%). Thus, the observed width of the SOA range was typically 600–800 ms, roughly consistent with contrast and duration change, yet some exceptions were observed.


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

Masuda A, Watanabe J, Terao M, Yagi A, Maruya K - Front Hum Neurosci (2014)

Results of experiment 1 (durations of COC edge and frame element were 200 ms). The description of each graph is the same as in the caption of Figure 5.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4217394&req=5

Figure 6: Results of experiment 1 (durations of COC edge and frame element were 200 ms). The description of each graph is the same as in the caption of Figure 5.
Mentions: The apparent brightness was estimated for each condition by calculating the PSEs. When the COCe is observed, the PSE is yielded at a positive contrast value, and a larger PSE indicates that a stronger COCe occurred. In all conditions, the dynamics of the PSE against SOA conditions (COCe dynamics) draws a bell-shape (Figures 5A, 6A for 50 ms durations of the COC edge and frame element and for 200 ms durations, respectively). The maximum PSE was around 15% (15.4, 13.2, and 21.6% for AM, YM, and TF, respectively). In the control condition, the estimated PSEs were around 3% (2.7, 1.4, and 4.2% for AM, YM, and TF, respectively). The maximum COCe size increased as the luminance contrast of the frame element increased when the durations of COC edge and frame element were 50 ms (Figure 5B) and 200 ms (Figure 6B). The COCe decreased as the absolute value of SOA increased. The COCe at largest SOAs (±400 ms) was not significantly different from the COCe in the control condition among all contrast and duration conditions (Figures 5C,D, 6C,D). In most conditions, the range of the SOA, in which the presence of the frame element was significantly effective (hereafter called the SOA range; see also Figure 2) was between −300 and 300 ms, except for several conditions where the frame duration was 50 ms and the contrast was low (< = 10%). Thus, the observed width of the SOA range was typically 600–800 ms, roughly consistent with contrast and duration change, yet some exceptions were observed.

Bottom Line: Also, the COCe is greatly reduced when the stimulus lacks a frame element surrounding the COC edge (Purves et al., 1999).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).

View Article: PubMed Central - PubMed

Affiliation: Department of Integrated Psychological Science, Kwansei Gakuin University Nishinomiya, Japan.

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.

No MeSH data available.


Related in: MedlinePlus