Fig 1.
Venetian blind effect examples.
Stereograms of rectangular-wave gratings with zero geometric disparity and (a) a luminance disparity corresponding to a dichoptic luminance modulation of approximately 0.8 or (b) a contrast disparity corresponding to a dichoptic contrast modulation of approximately 0.8, for demonstrating the Venetian blind effect. Either crossed or uncrossed fusion is appropriate. If crossed fusion is used, the lighter bars of the fused image will appear to rotate with the left edge of each bar appearing closer to the viewer. If uncrossed fusion is used, the lighter bars of the fused image will appear to rotate with the right edge of each bar closer to the viewer.
Fig 2.
Stereogram of "crystal" image with maximum luminance disparity for demonstrating binocular luster, taken after the written description by Helmholtz [9, 10]. Either crossed or uncrossed fusion is appropriate. The entire fused image will shimmer.
Fig 3.
Stereogram of gratings image with a geometric disparity for demonstrating binocular rivalry, taken after Panum [15]; Panum's gratings were at diagonals instead of horizontal and vertical). Either crossed or uncrossed fusion is appropriate. The entire fused image will rival.
Fig 4.
Data for (a) participant JJD, (b) RSH, and (c) WWS. Each plot, from top to bottom, shows probability of detecting rivalry ("riv"), luster ("lstr"), and rotation ("Vb") at different modulations. The left plots are for luminance ("lum") and right are for contrast ("con"). Filled boxes are for the left "eye" condition and empty boxes for right "eye." The vertical dotted line is the point where the light bars begin to straddle the background. Error bars indicate one standard error based on the score estimator [60] (see also [61, 62]). Open squares represent the probability of responding "present" for perceived rivalry (riv), luster (lstr), and rotation (the Venetian blind effect, Vb) when the right eye viewed the stimulus with higher average luminance or contrast and filled squares represent the case when the left eye viewed the stimulus with higher average luminance or contrast. Curves are least-squares fits of Laplace cumulative probability distributions, with dashed for the case when the right eye viewed the stimulus with higher average luminance or contrast and solid for the case when the left eye viewed the stimulus with higher average luminance or contrast [6].
Fig 5.
(a) The "average luminance" condition, with luminance values derived from a grating with dichoptic luminance modulation of 0.4. (b) "Light luminance bars," from dichoptic luminance modulation of 0.4. (c) "Light contrast bars," from dichoptic contrast modulation of 0.5. (d) "Dark bars," from dichoptic luminance modulation of 0.4. The bars straddle the background in (a) and (b), and not in (c) and (d).
Fig 6.
Data for participants (a) JJD, (b) RSH, and (c) WWS. From top to bottom for each plot, probability of detecting rivalry ("riv"), luster ("lstr"), and rotation ("Vb") at different modulations. The top left plot is for "average luminance" ("avg"), top right "light luminance bars" ("llm"), bottom left "light contrast bars" ("lcn"), and bottom right "dark bars" ("dar"). Filled boxes are for the left "eye" condition and empty boxes for right "eye." The vertical dotted line is the point where the light bars begin to straddle the background. Error bars indicate one standard error based on the score estimator [60] (see also [61, 62]). Open squares represent the probability of detecting rivalry ("riv"), luster ("lstr"), and rotation ("Vb") when the right eye viewed the bars with the higher luminance and filled squares represent the case when the left eye viewed the bars with the higher luminance. Curves are least-squares fit of Laplace cumulative probability distributions, with dashed for the case when the right eye viewed the bars with the higher luminance and solid for the case when the left eye viewed the stimulus with higher luminance [6].
Fig 7.
Model Predictions for perceived rotation.
Predictions of the probability of perceiving rotation by the generalized difference model coupled with the presumed relationship of average luminance and contrast in controlling the response rate of neurons described by Eq (2) for participants (a) JJD, (b) RSH, and (c) WWS. The top left plot is for "average luminance" ("avg"), top right "light luminance bars" ("llm"), bottom left "light contrast bars" ("lcn"), and bottom right "dark bars" ("dar"). Probability of perceiving a rotation data are from the corresponding plots in Fig 6. Filled boxes are for the left "eye" condition and empty boxes for right "eye." Error bars indicate 95% confidence intervals based on the score estimator [60] (see also [61, 62]).