Figure 1.

Schematic of the trial events in the experiments. Trials started with the choice display where participants had to choose either the “1” or “3” key in order to try to influence the valence of the subsequent image. The display remained on the screen until a choice was recorded. A fixation display was then presented for a random interval anywhere between 400 and 900 ms. This variable interval was followed by the presentation of the emotional picture which was presented for one of seven possible durations (400, 600, 800, 1000, 1200, 1400, and 1600 ms). The image then was replaced by a blank screen for 300 ms. Then participants were prompted to categorize the image duration as short of long on the final display.