1. When the + sign appears, participants can start the time interval by pressing the space bar;
  2. When the circle appears, time is running. When participants think that their given seconds have passed, they have to press the space bar again;
  3. Participants receive feedback for how accurate they have been (Fig. metti figura dal dropbox)
If the middle circle lights green, participant estimated the interval perfectly. If one of the left circles light up, you were too fast. If one of the right circles light up, the participant was too slow.
Participants played 10 practice trials and  how many. Participants were warned that, when estimating the time duration, they were not allowed to count time or tap their fingers or feet.
 
Choice Task 1 
In this task, participants need to decide which of the two flashing circles flashes most often by pressing x if they thought the left circle flashes most often, or m if they think the right circle flashes most often. Participants played 10 practice trials and were asked to respond as fast as possible without making any mistake. The computer automatically times out after 8 seconds of no response. After the practice phase, participants repeated this task for 250 trials. Participants received feedback for 0.50s after each decision.