Figure 2

Task design. A central fixation (500 ms) was followed by a cue (neutral or peripheral): part one reports only data derived from the neutral cue-condition. After a delay of 53 ms, stimuli were presented for 40 ms. The short period of stimuli presentation preclude saccadic eye movement, allowing to access the influence of exogenous covert attention. In each trial, participants were instructed to answer the question, “Is the stimulus that looks higher in contrast tilted to the right or left?” or “Is the stimulus that looks more colorful tilted to the right or left?” Participants chose from four options and responded by pressing one of the four designated response keys: left stimulus, tilted to left (‘z’ key); left stimulus tilted to right (‘x’ key); right stimulus, tilted to left (‘n’ key); or right stimulus, tilted to right (‘m’ key).