Adjustment of visual selectivity in tasks with coexisting Simon- and Stroop-like conflicts

The proportion congruency (PC) effect is a congruency effect that decreases as the ratio of congruent to incongruent trials within a given block increases.Researchers have been interested in the transference from a set of congruent to incongruent trials, with different ratios to a set of congruent and incongruent trials with equal ratios (diagnostic task).This present study investigated whether the PC effect is transferred across tasks with a coexisting Stimulus-Response conflict (Simon task) and Stimulus-Stimulus conflict (spatial-Stroop task) in a Stimulus-Response compatibility task.Right-handed students (N = 16) were required to identify the direction of an up/down arrow presented in four possible locations (right/up, right/down, left/up and left/down).We observed the transference from two perspectives, i.e., the Simon and spatial-Stroop views.The results indicated that the PC effect was not transferred across different types of conflicts.Therefore, these results suggest that attentional control in the Simon and spatial-Stroop tasks is independent and has a simultaneous effect.