Poster 10

Lightness Perception in a Naturalistic Environment: A Pilot Study on Human Visual Behaviors

Constance Marion

The present study examines behavioral differences between what we are calling "Super Seers" and most others observers performing a lightness judgment task in a natural lighting environment using an eye-tracking apparatus. Super Seers can correctly perceive surface lightness in Simultaneous Lightness Contrast (SLC) effects, while other observers will errors or a lightness illusion. The researchers hypothesized that there would be differences in comparative eye movements between Super Seers and others, with Super Seers focusing on the target and others using a back-and-forth motion to compare the target's surface lightness to the surrounding environment. To determine whether a participant was a Super Seer, they were asked to judge surface lightness of an SLC effect. All participants were then trained on a 5-point grayscale with black and white as anchors and asked to identify the shades of gray under controlled, indoor lighting. Once the participant was comfortable identifying shades of gray, they put on the eye-tracking apparatus and were guided outside. They were asked to walk along a natural wooded path and periodically identify the shade of a gray target placed in the brush using the grayscale. A photometer measurement was taken of the target under the natural lighting while the participant made their judgment. Super Seers were found to have smaller areas of focus around the targets, and their eyes did not move as much when making lightness judgments.

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