FIGURE 1.

Illustration of Simon effect used to evaluate the non-conscious processing of information in time. The two stimuli displayed on the screen were separated by a variable stimulus onset asynchrony. Subjects decided whether the two stimuli were simultaneous or asynchronous and gave their response on the left side or on the right accordingly. When asynchronies were shorter than 20 ms and simultaneity ratings were identical to those observed witth synchronous stimuli, healthy subjects nonetheless tended to press to the side of the 2nd occuring square, whereas patients tended to press to the side of the 1st square.