Fig 1. Exemplary illustration of an experimental trial.

The target stimulus consisted of an arrow appearing at one of four possible positions with respect to the fixation cross (upper-left, upper-right, lower-right, and lower-left) and pointing towards one of the same four directions. On each trial, participants had to respond to the direction of the arrow regardless of the position where it appeared. Hence, trials could be either congruent or incongruent, depending on whether the arrow direction (i.e., the task-relevant information) matched or not its position (i.e., the task-irrelevant information). Participants indicated the arrow direction by pressing four keys on their computer keyboard (E, O, K, and D, respectively), which were spatially arranged to ensure the dimensional overlap between the characteristics of the stimulus and the response. The appearance of the target arrow was preceded by the presentation of either a sad or a neutral facial expression, thus providing two emotional conditions.