> Objectives In this new experiment, we aim at replicating and extending previous findings regarding modulations over the interference effect as a function of the attentional set established by a secondary task with a different stimuli set. We will test the same attentional sets from Experiment #2, but stimuli will be presented as vertical arrows pointing either up or down. Therefore, the five arrows string will be presented at the left or the right of the fixation point. > Sample size As in Experiment #2, we propose to run a total of 20 participants. Estimation of this N is based on power analysis and can be reviewed in Experiment #2 of the current project. > Procedure and Design The procedure and design will be similar to the one of Experiment #2, except that the target and distractors will point either up or down and presented to the left or to the right of the fixation point. The script developed in E-Prime can be found in the files section. Four different blocks of 80 trials will be presented in a counterbalanced order and in one single session. The target will be largely displaced left-right/up-down from its central position in 20% of the trials in each block. In two of the four blocks, the displacement will be set on the horizontal axis (left-right displacement), and in the others two blocks on the vertical one (up-down displacement). For the two blocks with the infrequent horizontal displacement, participants will receive different instructions (by counterbalance selection). In one block, they should resolve only the flanker task in all trials (independently on whether the central target is displaced or not). In the other block with infrequent horizontal displacement, participants will be encouraged to be aware of the target displacement to detect it as soon as possible, while resolving the flanker task in the rest of the trials. The same two different instructions will be set for the two blocks with the infrequent vertical displacement. > Hypotheses Again, we expect to observe no differences in the executive control functioning (i.e., the interference effect, both for RT and percentage of errors), depending on the direction of the displacement, when participants do not need to deploy attention to the infrequent target displacement (i.e., just resolving the flanker task). In other words, there will be no differences in the size of the interference effect observed in the blocks with horizontal and vertical displacement in 20% of the trials, when a single task is performed. Importantly, and in contrast to to Experiment #2, in the dual task conditions, we expect to find an increment in the interference effect when the attentional set of the dual task is established to detect the infrequent vertical displacement, a reduction in the interference effect when the attentional set of the dual task is established to detect the infrequent horizontal displacement of the target. It s probable that, as it was found in the others experiments of the current project, the reduction of the interference effect would result even to a smaller size than when participants are focused only on resolving the flanker task.