Phonological codes are early sources of constraint in visual semantic categorization.

Two experiments were directed at early phonological activation in the semantic categorization task. In Experiment 1, briefly exposed targets homophonic to category exemplars (ROWS for the category A FLOWER), and their graphemic controls (ROBS), were judged for category membership with and without a backward pattern mask. False positives were greater for ROWS than ROBS to the same degree under both unmasked and masked conditions. In Experiment 2, false positives were examined in the semantic categorization task under backward dichoptic masking by pseudowords that were, in turn, masked monoptically by a pattern mask. Briefly exposed homophones (e.g., WEAK), masked by a phonologically similar pseudoword ("feek"), a graphemic control ("felk"), or an unrelated pseudoword ("furt"), were categorized as category exemplars (A UNIT OF TIME). The difference in false positives was significant for WEAK-feek versus WEAK-furt, but not for WEAK-felk versus WEAK-furt. It was suggested that the persistence of the homophonic effects under the pattern masking of Experiment 1 and their amplification under the phonological masking of Experiment 2 were because phonological codes cohere rapidly and provide, thereby, immediately available constraints on semantic processing.