Semantic negative priming in picture categorization and naming

Ignoring a particular stimulus can hamper subsequent attended processing of the same stimulus, a phenomenon known as 'negative priming'. Previous research has yielded partial support for the claim that the effect results from the attentional inhibition of central representations, as suggested by the fact that it appears to extend to semantic associates of ignored stimuli. In the current experiment, participants categorized or named pictorial stimuli with superimposed distractor pictures; the effect of unrelated, identical, or categorically related previously ignored pictures was investigated. Furthermore, visual similarity between categorically related picture pairs was manipulated in the naming task. The results indicated negative priming from identical ignored pictures irrespective of task. However, semantic negative priming was observed in the categorization task only. In the naming task, even visual overlap between categorically related picture pairs failed to induce negative priming. These findings argue against a central locus of the negative priming effect.