Figure 2.

Experimental set-up and analysis of color/luminance preference test

(A) Equipment set-up: The computer monitor is set to display the test stimulus.

(B) The test dish is placed on the displayed stimulus such that one quarter of the dish represents the region of interest (ROI).

(C) Graph represents the visual preference of tadpoles across a 30-min trial. The preference is determined by counting every minute, on the minute the number of tadpoles that reside in the ROI. The overall preference for the ROI during the trial is determined by averaging the preference across the 30 time-points. Dashed line represents the average number of tadpoles in the ROI that would be expected if there is no preference for, or avoidance of, the ROI.