Semantic priming revealed by mouse movement trajectories

Congruency effects are taken as evidence that semantic information can be processed automatically. However, these effects are often weak, and the straightforward association between primes and targets can exaggerate congruency effects. To address these problems, a mouse movement method is applied to scrutinize congruency effects. In one experiment, participants judged whether two numbers were the same ("3\3") or different ("3\5"), preceded by briefly presented pictures with either positive or negative connotations. Participants indicated their responses by clicking a "Same" or "Different" button on the computer screen, while their cursor trajectories were recorded for each trial. The trajectory data revealed greater deviation to unselected buttons in incongruent trials (e.g., "3\5" preceded by a green traffic light picture). This effect was influenced by the type of responses but not by prime durations. We suggest that the mouse movement method can complement the reaction time to study masked semantic priming.