Negative compatibility effect at post-categorical level

In contrast to the conventional compatibility effect, Negative Compatibility Effect (NCE) refers to the phenomenon of slower RTs in the compatible condition than in the incompatible condition. Two experiments employed a Stroop-like task in which the target and task-irrelevant stimulus were dissimilar in terms of shape and color. While conventional compatibility effects were found when the task-irrelevant stimulus and target were spatially close, NCE was observed when they were separated. Moreover, NCE was not re- sponse-modality dependent (oral / manual). These results cannot be explained by the hypothesis that NCE is caused an inappropriate allocation of spatial attention due to the similarity in shape between target and task-irrelevant stimulus (Bavelier et al., 2000). Thus, NCE seems to reflect inhibitory processing at the post-categorical level.