The Impact of Categorical Proximity on Positive and Negative Priming: Evidence from Categorisation and Naming Tasks

This study compares the breadth and temporal dynamics of positive and negative priming effects depending on the depth of stimulus processing. Two experiments were conducted using a Naming task (shallow processing) and a semantic Categorisation task into "living/non-living" (deep processing) with varying categorical proximity of the prime and probe. A dissociation between the patterns of positive and negative priming was observed. Positive priming emerged exclusively in the Categorisation task, demonstrated graded sensitivity to categorical proximity, and increased with longer response times, consistent with spreading activation models. Negative priming, by contrast, was observed in both tasks: in the Naming task, it appeared as a stable effect independent of categorical proximity, whereas in the Categorisation task, it manifested as a short-lived effect restricted to fast responses. These findings support the early automatic inhibition account and contradict the predictions of episodic retrieval models. Overall, the results indicate functional differences between positive and negative priming under the present conditions: whereas positive priming appears to implement fine-grained semantic tuning, negative priming serves as a coarse, early inhibitory mechanism operating at the level of generalised representations.