Figure 1.

Outline of the global-to-local paradigm and stimuli. A trial started with the presentation of a fixation cross lasting between 1 and 1.5 s followed by the presentation of one of eight possible stimuli displayed in (A). Subjects had to detect the target numbers 1 and 2 which appeared either at the global level or at the local level of the hierarchical stimulus and respond as quickly as possible via button press. They were instructed to press the “Z” key when the target 1 appeared and the “M” key when the target 2 appeared. The stimulus itself was presented for 100 ms and replaced by a blank shown until the subject responded via a button press. (B) Outline of a single trial.