Schematic representation of the experimental design.

<p>(A) Trial timeline. Each trial started with a 1 second baseline period (pre-cue period), after which a letter cue was shown for 0.5 s (‘L1’ = near-left and ‘R1’ = near-right at 3.5° eccentricity; ‘L2’ = far-left and ‘R2’ = far-right at 7° eccentricity). Next, subjects had to covertly attend to the placeholder at the cued location whilst fixating at the white fixation cross for a random period in the range between 0.5 and 3 seconds (pre-target period). Then, a target was shown within the cued placeholder for 0.05 s. Next, the fixation cross turned from white to black and the subject had to press a button to indicate which target (−45° or +45°) he/she detected. Finally, feedback was shown (green cross = correct, red cross = incorrect) and after two seconds the next trial started. (B) Targets. Gabor patches with left orientation (−45°) or right orientation (+45°), shown here at full contrast.