Fig 1.
Sample image pair of the spot-the-difference game.
This image contains 6 differences (position of bubbles, eye-brow of the larger fish, scale of the larger fish, tail fin orientation of the larger fish, image of face in the helmet of smaller fish and rivet in the helmet of smaller fish) used in Experiment 1. This image pair can be cross-fused using convergence eye movements to create the cyclopean percept and experience the fusion mode of gameplay.
Fig 2.
Panel A shows the mean (±1 SEM) time taken to complete the task for the four different level of task complexity (3, 6, 9 and 12 differences) in the non-fusion (NF) and fusion (F) modes of gameplay in Experiment 1. Panel B shows the mean (±1 SEM) difference in the time taken between the non-fusion and fusion modes of gameplay for each level of task complexity. Panel C shows the total number of misses of local feature differences across all participants for a given level of task complexity in both modes of gameplay in Experiment 1. The horizontal line above each pair of bars in this panel indicate the total number of differences that had to be identified for that task complexity. The % values for each pair of bars indicate the misses in a percentage scale. Asterisk symbols indicate statistically significant difference between each pair of data obtained in the fusion and non-fusion mode of gameplay. *: p-values between 0.05 and 0.01, **: p-values between 0.01 and 0.001 and ***: p-values <0.001.
Fig 3.
Panel A shows the percentage of times a given difference was identified as the first amongst all the possible differences in an image for difference task complexity in Experiment 1 for non-fusion (NF) and fusion (F) modes of gameplay. Panel B shows the mean (±1 SEM) time taken for first correct identification of a difference in a given image for the three types of local feature differences. Given that the polarity difference was overwhelmingly identified as the first in both modes of gameplay, the number of data points that were averaged to compute the mean and SEM in panel B are larger for this difference, relative to the other two. Asterisk symbols are same as Fig 2.
Fig 4.
Sample grayscale image pair with 50% luminance contrast and 3° angular subtense used in Experiment 2 (Panel A). Mean (±1 SEM) time taken for task completion across target contrasts and sizes in the non-fusion (NF) and fusion (F) modes of gameplay in Experiment 2 (panels B–D). Mean (±1 SEM) difference in the time taken between the two modes of gameplay for each combination of target contrast and size (panels E–G). Asterisk symbols are same as Fig 2.
Fig 5.
Sample image pair along the red-green color axis (140 – 320o hue angle) with 75% color saturation used in Experiment 3 (Panel A). Mean (±1 SEM) time taken for task completion across target color saturations and hue angles (panels B–D). Mean (±1 SEM) difference in the time taken between the non-fusion (NF) and fusion (F) modes of gameplay for each combination of color saturation and hue angle (panels E–G). Asterisk symbols are same as Fig 2.
Fig 6.
Sample image pair used in Experiment 4 (Panel A). This image contains difference pairs with opposite luminance polarity that is meant to enhance the experience of lustre (top left square, middle-right hexagon and bottom left square) and difference pairs with same luminance polarity that weakens the experience of lustre (top circle, middle hexagon and bottom-right hexagon). Mean (±1 SEM) time to task completion for difference pairs with opposite luminance polarity (Opp pol) that enhances the experience of binocular lustre and difference pairs with same luminance polarity (Same pol) that weaken the experience of binocular lustre (Panel B). Each pair of bars show data from the non-fusion and fusion modes of gameplay. Asterisk symbols are same as Fig 2.