Figure 1. Experimental paradigms for the “observation task” (left) and “sequencing task” (right).

In both tasks, stimulus presentation lasted 4sec. Only in the “sequencing task” the stimulus was followed by the command to digit on the keyboard the correct sequence. for Both sequencing and observation tasks had an intertrial period of 1.5sec, followed by a new trial. In the left panel two consecutive trials are shown, one representing a biological action and the other representing a physical event.