Figure 1.

Experimental setup. The beginning of the trial was signaled by a “+” appearing in the centre of the screen for 1 s, followed by the presentation of the premise categorical proposition for 2.5 s. Thereafter the sentence disappeared for 0.5 s (Waiting period), followed by the presentation of the conclusion categorical proposition for 2.5 s. Then, a question mark appeared for 1.5 s, requiring the subject to press one push button if the conclusion contradicted the premise and a different push button if the conclusion did not. If they were unable to make a clear choice, they were told to omit the response (i.e., to not push either button). Finally, a feedback advised the subject whether any button had been pressed or not, with no indication about the correctness of the contradiction identification. “New Trial” appearing on the screen advised the subject that the next trial was starting.