a slight trendp > 0.1
We speculate that our test setting provided the visual system rich cues to the context that it could use to identify that the “normal” environment was present and so adjust rapidly to its “normal mode.” Adaptation within a given session reached a limit; during the last hour of adaptation, unique yellow settings did not even show a slight trend toward increasing (slope of a linear fit to settings during the last hour did not significantly differ from zero on all 5 days, all p > 0.1).