Reports of a processing advantage for polysemes with related senses (e.g., <printer>/<academic> PAPER) in lexical decision and a processing disadvantage for homonyms (e.g., <river>/<money> BANK) in semantic categorization have prompted the development of conflicting accounts of these phenomena. Whereas a decision-making account (Hino, Pexman, & Lupker, 2006) suggests these effects are due to qualitative differences between the tasks, accounts based on temporal settling dynamics (Armstrong & Plaut, 2008) suggest that processing time is the critical factor. To compare these accounts, we manipulated nonword difficulty and stimulus quality to make lexical decision difficult and attempted to produce the same homonymy disadvantage as in semantic categorization. We found that stimulus degradation succeeded to this end, and nonword difficulty only consistently slowed nonword responses. This provides evidence both for settling dynamics accounts of semantic ambiguity in particular, and for interactive orthographic-to-semantic processing and the construction of more integrated models, in general.