Introduction ------------ In a previous study recently submitted to publication (Luna, Marino, Roca, & Lupiáñez, 2017), we conducted two experiments to analyze the decrement on executive vigilance (i.e., detection of infrequent events across time) and arousal vigilance (i.e., reaction to stimuli without control over response; only in the second experiment) simultaneously. At the same time, participants resolved a flanker task with visual cues and warning signals, to assess the functioning of the classic attentional networks (i.e., phasic alertness, orienting, and executive control). The main task was to discriminate the direction of the central arrow (target), which was flanked on each side by two distracting arrows, pointing either in the same or opposite direction. The embedded executive vigilance task consisted on the detection of a large displacement of the target from its central position. Additionally, in both experiments we compared two different task versions: one group should detect a large ‘horizontal’ displacement, while the other group had to detect a ‘vertical’ displacement. The results showed that task versions differed significantly in the overall reaction time (RT; first experiment [F (1, 46) = 7.51, p = .008, ηp^2 = .14], second experiment [F (1, 72) = 11.85, p < .001, ηp^2 = .14]) and percentage of errors (first experiment [F (1, 46) = 15.03, p < .001, ηp^2 = .24], second experiment [F (1, 72) = 12.71, p < .001, ηp^2 = .15]) in the flanker task resolution, even if those trials were exactly the same in the two task versions (i.e., trials without the large displacement). Faster RT and fewer errors were observed in the vertical than in the horizontal version in both experiments. Additionally, and more importantly, executive control interacted with task version in both experiments: a smaller interference effect (i.e., the difference between incongruent and congruent conditions) was found in the vertical than the horizontal version, for both RT (first experiment [F (1, 46) = 24.34, p < .001, ηp^2 = .35], second experiment [F (1, 72) = 50.51, p < .001, ηp^2 = .41]) and percentage of errors (first experiment [F (1, 46) = 33.02, p < .001, ηp^2 = .41], second experiment [F (1, 72) = 63.08, p < .001, ηp^2 = .47]). We did not anticipate these overall differences based on the task version, and most important, the modulation over executive control (see data on the Figure 1 from the Files folder). Experiment #1 of the current project ------------------------------------- Then, we conducted a new experiment in which participants would only have to respond to the flanker task (i.e., never to the displaced infrequent target or the arousal vigilance task). In this experiment we did not expect to observe any difference in the flanker task resolution between task versions, neither for overall RT or percentage of errors, nor for the executive control measure. We believed that the main effects of task version and its interactions with executive control observed by Luna et al (2017) resulted from the ‘attentional set’ established for the whole task, in order to deal with the displaced (either vertically or horizontally) infrequent target used to resolve the ‘executive’ vigilance embedded task. It could be possible that the whole task turns more difficult to resolve when subjects have in mind the intention to attend to the target displacement in the horizontal than in the vertical direction. Then, when solving only the flanker task during this new experiment, there should be no effect of the target displacement as there should be no awareness of this infrequent stimuli detection, or at least there should be no intention to attend to it. Therefore, we reasoned, no differences should be found between task versions. We tested these hypotheses in the first experiment of the current project, in which we expected to observe very similar results for the two task versions as subjects do not need to attend to the target displacement (i.e., only resolving a flanker task but with exactly the same stimuli presentation of the previous experiments of Luna et al., 2017). Main results of the Experiment #1 --------------------------------- The results obtained (see Figure 1 on the Files folder, the bars over the ANTI* task versions) confirmed that when participants must only resolve the flanker task, no overall differences are observed between task versions, both for RT [F (1, 43) = 0.52, p = .476, ηp^2 = .01], and percentage of errors [F (1, 43) = 0.03, p = .853, ηp^2 = .00]. Most important, no modulation of task version was observed on the interference effect, neither for RT [F (1, 43) = 0.04, p = .838, ηp^2 = .00], nor for the percentage of errors [F (1, 43) = 0.99, p = .325, ηp^2 = .02]). These results supported our hypothesis that when the ‘attentional set’ is reduced to resolve a single task, there are no differences on the functioning of the executive control network. Instead, when participants must also detect infrequent stimuli, the ‘attentional set’ needs to increase to resolve two (i.e., ANTI-V task from the previous study) or three (i.e., ANTI-Vea task from the previous study) simultaneous tasks. Importantly, depending on the nature of the task set, the functioning of the executive vigilance network (which is involved in discriminating the left-right orientation of the central target embedded within distracters), will be benefited by attention being deployed to the up/down displacement of the central target, or impared by attention being deployed to the left/right displacement of the central target. Objectives for Experiment #2 ---------------------------- We propose to replicate and confirm the differences observed in the previous experiments in the interference effect as a function of the attentional set established, in a single within-participants design. We will test the same attentional sets from the previous experiments, but now without the stimuli for measuring orienting (visual cue), phasic alertness (warning signal), and arousal vigilance across time (a milliseconds down counter). Sample size for Experiment #2 ---------- Using G*Power 3.1.9.2 (Faul, Erdfelder, Lang, & Buchner, 2007), the estimated sample size was a minimum of 14 subjects, based on the effect size of the Task version x Executive control interaction in RT of the first experiment in the previous study, with a power of .95 and an alpha error of .05. In order to have the same number of participants in each condition and to anticipate the need for replacing outliers, we decided to run a total of 20 participants. Procedure and Design for Experiment #2 -------------------------------------- Four different blocks of 80 trials will be presented in a counterbalanced order and in one single session. The target will be largely displaced from it 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, and in the others two blocks on the vertical one. 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. Hypothesis for Experiment #2 ---------------------------- We expect to observe no differences in the executive control functioning (i.e., the interference effect, both for RT and percentage of errors) when participants do not need to deploy attention to the infrequent target displacement (i.e., just resolving the flanker task). We expect to find an increment in the interference effect when the attentional set is established to detect the infrequent horizontal displacement while resolving the flanker task. Furthermore, it is possible that when the attentional set is instructed to detect the infrequent vertical displacement at the same time that performing the flanker task, the interference effect will be reduced, even to a smaller size than when participants are focused only on resolving the flanker task. References ---------- Faul, F., Erdfelder, E., Lang, A. G., & Buchner, A. (2007). G*Power 3: a flexible statistical power analysis program for the social, behavioral, and biomedical sciences. Behav Res Methods, 39(2), 175-191. Luna, F. G., Marino, J., Roca, J., & Lupiáñez, J. (2017). Executive and arousal vigilance decrement in the context of the attentional networks. Manuscript Submited to Publication.