Effects of orthography on speech production in a form-preparation paradigm

Four experiments investigated potential influences of spelling on single word speech production. A form-preparation paradigm that showed priming effects for words with initial form overlap was used to investigate whether words with form overlap, but different spelling (e.g., "camel"-"kidney") also show priming. Experiment 1 demonstrated that such words did not benefit from the form overlap, suggesting that the incongruent spelling disrupted the form-preparation effect. Experiment 2 replicated the first experiment with an independent set of items and an improved design, and once again showed a disruptive effect of spelling. To divert participants’ attention from the spelling of the targets, Experiment 3 was conducted entirely in the auditory domain, but yielded the same outcome as before. Experiment 4 showed that matching initial letters alone, in the absence of matching sounds (e.g., "cycle"-"cobra"), did not produce priming. These findings raise the possibility that orthographic codes are mandatorily activated in speech production by literate speakers.