Lexical access codes in visual word recognition: Are the joint effects of context and stimulus quality diagnostic?

Is it possible to identify when lexical access in visual word recognition i s based on an orthographic code and when it is based on a phonological code ? Some researchers have argued that the joins effects of semantic context a nd stimulus quality in lexical decision are diagnostic. Their argument is t hat when phonological recoding is employed, it serves to keep the effects o f stimulus quality and context from interacting. Semantic context and stimu lus quality are therefore predicted to have additive effects on RT. In cont rast, when lexical access is not mediated by a phonological recoding stage, then the effect of stimulus quality interacts with context, as commonly se en in the literature. A strong test of these claims was devised in which pa rticipants were forced to use phonological recoding for the purpose of lexi cal access. An interaction between context and stimulus quality was observe d. This finding is taken as evidence that the joint effects of semantic con text and stimulus quality are nor diagnostic with respect to the nature of the lexical access code (i.e., orthographic versus phonological) for reader s of English.