Target-response contingency learning is not modulated by cognitive control demands

People form associations between stimuli and responses, resulting in faster responses to stimuli that occur more frequently. This type of frequency-based stimulus-response (S-R) contingency learning has often been claimed to confound putative effects of cognitive control in conflict tasks, like the Stroop task. However, the underlying assumption that contingency learning of target-response associations itself is not modulated by cognitive control demand remains unanswered. To assess whether the presence and congruency of distracters alters contingency learning, we had participants perform a face-gender Stroop classification task, either without (“nonconflict task”) or with congruent and incongruent distractor word labels overlaid (“conflict task”). Importantly, we also manipulated the frequency at which specific face images were displayed (1, 5, or 10 times) in order to measure contingency learning. If cognitive demand facilitated contingency learning, we would see more pronounced learning effects in the conflict task than in the nonconflict task. By contrast, if cognitive demand interfered with contingency learning, we would see less pronounced learning effects in the conflict task. Across a preregistered within-participant and a separate between-participant Experiment, we observed additive main effects for image frequency and task type, with a standard S-R contingency learning effect, a standard Stroop congruency effect, and faster categorization of faces when no distractor word label was presented. Crucially, there was little evidence for an interaction effect between task and stimulus frequency, thus documenting that contingency learning occurs independently of cognitive demand in a typical conflict task. Implications for these findings are discussed.