Complexity and specificity of experimentally induced expectations in motion perception Supplementary Materials

For each session of the experiments, the staircases reached stable luminance levels after approximately 200 trials (Supplementary figure 1). A slow luminance descent was used to allow bigger variations in participants' performance and color sensitivity, as a few participants had significantly higher threshold levels than the average. Additionally, green dots were expected to be easier to detect than red dots at equal luminance levels. Thus, for each staircase step, the luminance was decreased by 0.025 cd/m 2 for the red dots and by 0.03 cd/m 2 for the green dots. Green levels of luminance, averaged over participants, were significantly closer to the background luminance than red ones, thus justifying the use of two different staircases.